Dresser-Rand. Instruction Manual for Single Stage 350, 500, and 700 Frame Steam Turbines (2011)

SST Turbine Instruction Manual

Speed Control System

TURBINE

WHEEL

NOZZLE

RING

HAND VALVE

(OPEN POSITION)

Figure D-5. Hand Valve Arrangement

Hand-valves must be fully open or fully closed. Operation with a partially open

hand-valve is equivalent to throttling, meaning that efficiency is lower. It will also

cause steam cutting damage to the valve seats.

When closing hand-valves, close the valve furthest from the inlet flange first. Open

hand-valves using the opposite sequence. This will prevent interrupted flow from

nozzles to the blades, which will subject blades to unnecessary stress cycles and

could reduce turbine efficiency.

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Section E

Overspeed Trip System

E.1

General

In the event of an overspeed condition, caused by a sudden loss of load or failure

of the speed control system, the supply of steam to the turbine must be quickly and

positively interrupted, preventing damage to or destruction of the turbine or driven

equipment and possible personal injury. The turbine has a fixed amount of stored

energy in the steam or gas already downstream of the trip valve at the time that the

trip valve is closed. The turbine converts that energy to rotating mechanical

energy and transmits it to the driven machine. As it does so, with no additional

energy entering the turbine, the turbine slows down and comes to a stop.

An overspeed trip valve, activated by the over-speed governor cup assembly and/or

electronic trip system, performs this function.

Per NEMA SM23, Steam Turbines For Mechanical Drive Service, normal turbine

trip speed is 15% over maximum continuous speed for NEMA A (Woodward TG)

governors and 10% over maximum continuous speed for NEMA D governors.

Maximum continuous speed is 5% over rated speed; therefore, trip speed is 16%

(NEMA D) or 21% (NEMA A) over rated speed. Occasionally the trip speed set

point may be lower or higher than normal due to a customer request and/or

technical reason. The factory trip setting speed appears on the turbine nameplate.

Standard SST turbines are supplied with an overspeed governor cup assembly

(refer to Figure E-2, Overspeed Governor Cup Assembly), located within the

mounting housing on the steam end of the turbine shaft, which contains a spring-

loaded weight, within which resides a speed-adjusting set-screw. The weight,

spring, and setscrew are selected and set at the factory so that the weight snaps out

of the bushing at a predetermined trip speed. This trip speed is recorded on the

turbine data sheet and the turbine nameplate.

When the weight snaps out of the overspeed governor cup assembly (refer to

Figures E-2, Trip System), it strikes the trip paddle, which in turn releases the trip

linkage, causing the trip valve to close. As turbine speed decreases, the weight is

pulled back into the bushing by spring action. The trip valve can then be manually

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E.2

Warnings

CAUTION

If the KW load on a turbine-generator cannot be reduced in the

normal manner, it indicates the possibility of unacceptable

deposits on the control valve components.

STUCK CONTROL VALVES ARE A DANGER SIGNAL THAT THE

TRIP VALVE MAY ALSO BE STUCK. UNDER THESE

CONDITIONS IT IS IMPERATIVE THAT THE GENERATOR LOAD

NOT BE REMOVED UNTIL THE TRIP VALVE IS CLOSED.

If the trip valve cannot be closed by normal means, then other valves in

the steam system must be used to cut off the steam supply to the

turbine.

THE UNIT CIRCUIT BREAKER SHOULD NEVER BE OPENED

WHILE LOAD IS ON THE UNIT AND TRIP AND THROTTLE /

GOVERNOR VALVES ARE INOPERABLE. FAILURE TO

FOLLOW THESE PRECAUTIONS COULD CAUSE A SEVERE

OVERSPEED WITH EXTREME DANGER TO THE TURBINE

AND OPERATING PERSONNEL.

DANGER

NEVER BLOCK OR DISABLE THE TURBINE TRIP SYSTEM

OR ATTEMPT TO ADJUST OR REPAIR IT WHILE THE

TURBINE IS OPERATING.

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WARNINGS

TESTING, REPAIR AND MAINTENANCE of overspeed trip

systems must be performed only by trained and

EXPERIENCED PERSONNEL.

The OVERSPEED TRIP SYSTEM must always be TESTED

and adjusted, if necessary, when STARTING the steam

turbine.

The OVERSPEED TRIP SYSTEM must be TESTED WEEKLY

on turbines that operate continuously. This prevents build-up

of foreign material in the trip linkage and alerts the operator to

deterioration that may affect trip system performance.

The TRIP SYSTEM utilizes HEAVY SPRINGS; use CAUTION

when assembling or disassembling the mechanism.

The TRIP LINKAGE MOVES RAPIDLY WITH GREAT FORCE

when the turbine trips. Use CAUTION when ADJUSTING the

TRIP SYSTEM, MAINTAINING the turbine, or when

WORKING IN THE VICINITY of the OPERATING TURBINE.

WARNINGS

Always determine and CORRECT the cause of an

OVERSPEED TRIP BEFORE RESETTING THE VALVE AND

MECHANISM.

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DO NOT SET THE OVERSPEED TRIP SYSTEM to a speed

HIGHER than the factory setting without first consulting the

factory.

E.3

Description and Function

E.3.1

Overspeed Governor Cup Assembly

The overspeed governor cup assembly (Figure E-2) consists of the following parts.

Legend:

90. Cup - Governor

94. Spring

91. Screw - Adjusting

95. Bushing - Weight

92. Set Screw

96. Ring - Retaining-Open type

93. Weight

97. Ring - Retaining-External type

Figure E-2. Emergency Governor Cup Assembly

The weight (93), which is contained via retaining rings (96 and 97) within the

emergency governor cup (90), is installed within a lateral hole in the emergency

governor cup body (90). The emergency governor cup assembly is installed on the

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turbine shaft via key and set screw. The weight is heavy at the adjusting screw end

(upper part of Figure E-2, Emergency Governor Cup Assembly). As the shaft and

cup assembly rotates, centrifugal force tends to move the weight out of the cup,

compressing the spring (94). When turbine speed reaches the trip speed, centrifugal

force at the weight exceeds spring retention force, causing the weight to snap out,

tripping the trip linkage.

The speed at which the weight trips the linkage is a function of the weight (93),

bushing (95) shape and material, the spring rate of the weight spring (94), and the

position of the adjusting screw (91). The factory based on the desired trip speed

selects these components. In the field, trip speed is adjusted by changing the

position of adjusting screw (91). It is imperative that the setscrew (92) be tightly

turned into and locking the adjusting screw (91) from any movement. Refer to

Section E.5, Adjustment of Trip Speed, for adjustment and maintenance

instructions.

WARNING

Weight (93), spring (94), adjusting screw (91) and setscrew

(92) are a FACTORY-CONFIGURED SET, selected to obtain

the proper trip speed for a specific turbine. DO NOT MIX OR

INTERCHANGE THESE PARTS with similar parts from other

turbines or attempt to modify these components. Consult your

local Dresser-Rand manufacturer’s representative or the

factory if replacement parts are needed.

E.3.2

Trip Valve

The standard SST turbine trip valve (Figure E-3, Trip Valve, E-4 Trip System) is a

positive shut-off, force-actuated, sliding trip valve that is spring-loaded to ensure

fast action.

When the turbine is running, the trip valve is fully open, held in place by the trip

linkage (valve linkage lever (444), latch (445) and trip lever (490)), which is in

turn held by trip lever (583) action against the trip finger (584).

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426

Seat

427

Roll Pin

428

Valve

429

Stem

430

Cover

431

Cap Screw

432

Lock Washer

433

Plug

436

Bushing

437

Link

438

Set Screw

439

Packing

440

Gland Follower

441

Valve Spindle

444

Lever

1000

Valve Body

The trip linkage operates as follows:

Refer to Figures E-1, Typical Trip System Arrangement Drawing, E-2, Emergency

Governor Cup Assembly, E-3 Trip Valve and E-4, Trip System.

During trip valve reset, as the valve (428) approaches the fully open position, reset

handle (434) rotates trip lever and latch (444 and 445) into place with the knife

edge of the latch (445) into position into the slot on the trip lever (490). The trip

pin (577) then engages the trip lever (583), holding the valve in the open position.

There is a torsion spring, operating in the valve closing direction, applies tension to

trip pin (577). There is also a linear acting spring (510) that is pulling against lever

(444). This tension is transferred to the knife-edge, holding the linkage in the open

position. With the valve in the open position, inlet steam can now flow into the

turbine.

The trip valve can then be tripped, either manually or by an overspeed condition. If

overspeed occurs, the weight (93) will snap out of the weight bushing (95), striking

the trip lever (584), causing it to release trip lever (490). The trip shaft (441) is

rotated by retraction of torsion spring (510), extending the linkage, closing the trip

valve via stem (429) and link (437). The force of the longitudinal spring (510)

ensures positive closing of the trip valve.

When the system is tripped, a spring acting on pin (577) retracts, rotating lever

(490), thus allowing lever (444) and latch (445) to be pulled by spring (510) into

the closed position via the trip linkage, isolating the turbine from the steam supply.

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DANGER

Under no circumstances should the TRIP VALVE be blocked or

held open to render the trip system inoperative. Overriding the

trip system, and allowing the turbine to exceed the rated

(nameplate) trip speed, may result in FATAL INJURY to

personnel and extensive turbine damage. In the event the trip

system malfunctions, immediately SHUT DOWN the turbine

and remedy the cause.

Refer to Sections C.3.10, C.3.11, C.3.12 and C.3.13 for recommended drain and

leak-off piping configurations.

Optional construction may include a separate overspeed trip valve. Refer to the

certified drawings in Appendix A.

E.3.3

Trip Linkage

The standard SST turbine trip linkage, set in motion by movement of the weight

(93) in the governor cup assembly (90) Fig. E-2 controls the closing of the trip

valve. The linkage also allows the valve to be opened and latched in the open

position via reset handle (434), Fig. E-4. The design clearance at the end of the

governor controlled steam valve(s) and trip or trip and throttle valve stems are required

to minimize steam leakage from the turbine.

WARNING

NEVER OPEN A CLOSED TRIP VALVE without first preparing

the turbine and driven equipment for operation.

E.4

Trip System Operation

For SST turbines supplied with the standard trip linkage, if the overspeed trip valve

is tripped shut and the turbine stopped, either from an overspeed trip condition or

manual activation of the trip lever, the trip valve must be reset manually, as

described below.

E.4.1

Manual Reset

Use the following procedure to manually reset the over-speed trip valve:

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a. Close shut-off valve in inlet steam line as soon as possible after the turbine

trips.

b. Determine cause of the trip condition. It may be due to loss of the driven

machine load, a turbine fault, or a governor problem. Remedy the cause using

procedures detailed in Section K, Troubleshooting.

c. If the turbine is not at a complete stop, listen for weight retraction into the

weight bushing, or wait for turbine speed to drop to 75% of its rated value to

ensure resetting of the trip weight.

d. Lift reset handle (434 in Figure E-4) slightly (approximately 10-15 angular

degrees) to open trip valve (428 in Figure E-3).

e. When pressure in the valve body has bled off, continue lifting the reset handle

using minimal force, until the trip valve opens and the trip lever (490 in figure

E-4) latches on latch (445 in Figure E-4).

CAUTION

DO NOT try to FORCE or jerk open the TRIP VALVE.

g. Gradually open shut-off valve in inlet steam line to bring turbine up to normal

operating speed, allowing the governor to take control. Then open shut-off

valve to full open position and back off one-quarter turn.

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E.5

Adjustment of Trip Speed

E.5.1

Trip Speed Setting

It may become necessary to change the factory speed setting of the trip system due

to a change in the normal operating speed of the turbine.

Refer to the following figures:

Figure E-1, Typical Trip System Arrangement Diagram

Figure E-2, Emergency Governor Cup Assembly

Figure E-3, Trip Valve

Figure E-4, Trip System

Figure M-2, Governor, Mounting Housing, and Trip Components

Figure L-15, Governor Valve Travel Setting, Woodward TG Governor

For SST turbines supplied with the standard emergency governor cup assembly,

adjusting the position of the adjusting-screw (91) inside the governor cup (90) can

change this setting. Use the following procedure to set turbine trip speed:

a. Test the over-speed trip system per the Overspeed Trip Test Procedure specified

in Section E.6.2. Record the speed at which the weight triggers the over-speed trip

valve, stopping the turbine. Close isolating valve in inlet steam line to prevent

accidental restart.

b. For turbines with a Woodward governor with overspeed test device (type TG,

PG-PL and PG-D) remove test device cover located on top or end of the governor

(refer to Woodward instructions in Appendix B.)

c. Slide the end of the operating rod into its socket and turn it slowly. The turbine

speed will increase to tripping, and the turbine will trip out. For type UG

governors, the over-speed pin is located adjacent to the “Woodward” logo. Raise

up on this pin to over speed the turbine.

d. Turbines with Woodward governors without the over-speed device: Pry open

the governor valve, being careful not to damage the linkage. When trip speed is

reached, the turbine will trip out.

e. Turbines with electronic governors (Tri-Sen, CCC, and Woodward) -- refer to

the instruction manuals located in Appendix B for correct operating and testing

procedures.

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WARNING

FIELD CONFIGURABLE GOVERNOR

Any change to the control limits, such as (but not limited to)

speed, over-speed trip, control logic, other than “tuning” (see

governor manual) requires the prior written approval of

Dresser-Rand Company to assure that safe operating limits are

not exceeded. Failure to comply may result in damage to

property, serious injury or death to personnel.

The new trip setting should be approximately 21% above the rated speed for a

NEMA A (Woodward TG) governor and 16% above the rated speed for a NEMA

D governor.

f. Open inlet isolating valve and test turbine tripping several times after final

adjustment. If the trip speed is not repeatable within 2%, or if erratic operation

occurs, investigate and correct the problem before placing the turbine in normal

service.

If possible, carry out a daily check of the tripping mechanism during the first week

after adjustment, by over-speeding the turbine.

Optional construction may include an electronic overspeed trip system. Refer to

the certified drawings and the appropriate vendor instruction manual in Appendix

A and Appendix B for instruction on how to adjust the trip speed set point.

E.5.2

Magnetic Pickup Clearances

When supplied, maintaining the proper clearance between the magnetic pickups

(located on the turbine mounting housing) and the turbine shaft mounted signal

gear/device is crucial to the operation of the turbine electronic trip systems and

electronic governor systems. Refer to Figure E-5.

Prior to initial start up of the turbine, the clearances must be checked, adjusted and

the pickups locked into position.

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As a part of the routine checking and testing of the turbine, the magnetic pickups

should be visually checked for damage and the clearances verified to be within

tolerance.

Figure E-5. Air Gap Between Signal Gear and Magnetic Pickup

E.6

Testing the Overspeed Trip Mechanism

E.6.1

General

Before testing the overspeed trip system, the turbine must be visually inspected for

defects. Pay particular attention to governor and overspeed trip components and

correct the defects prior to initiating any tests.

Exercising of the governor-controlled valves may be performed choking the trip or trip

and throttle valve. At the same time, the trip or trip and throttle valve is exercised.

WARNING

RAPID CLOSING OF VALVES SUPPLIED WITH THE

TURBINE IS ESSENTIAL TO PROTECT AGAINST

OVERSPEED AND POSSIBLE OTHER MECHANICAL

PROBLEMS.

DANGER

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NEVER BLOCK OR DISABLE THE TURBINE TRIP SYSTEM

OR ATTEMPT TO ADJUST OR REPAIR IT WHILE THE

TURBINE IS OPERATING.

WARNING

The overspeed trip system may malfunction during testing. Use

caution when testing and be prepared to shut the turbine down

quickly with the inlet-isolating valve.

The overspeed trip system should be tested weekly to verify its operation, to

prevent build-up of foreign material on the trip linkage, and to alert the operator to

deterioration that may affect trip system performance.

Dresser-Rand recommends incorporation of testing into the plant

operating/maintenance program and the keeping of a log to record tests.

Any malfunction of the trip system should be investigated and corrected prior to

returning the turbine to service.

E.6.2

Overspeed Trip Test Procedure

Before testing of the overspeed trip system, the turbine must be visually inspected

for defects. Pay particular attention to governor and overspeed trip components and

correct any defect prior to initiating any tests.

Use the following procedure to test the SST Turbine over-speed trip system:

a. Start up the turbine per Section I.4.2, Initial Start-Up Procedure.

b. Manually trip the turbine by pressing on the trip lever (434). The over-speed

trip valve should close, shutting off the turbine steam supply and bringing it to

a stop. This confirms operation of the linkage and valve, but not the

emergency governor cup assembly. If the valve does not close, refer to Section

K, Troubleshooting. Otherwise, proceed to Step c.

WARNING

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The TRIP LINKAGE MOVES VERY RAPIDLY and abruptly

through its full travel when the turbine is TRIPPED. To guard

against serious hazards to operating personnel, they must

STAY CLEAR OF THE LEVER.

c. Open and latch the overspeed trip valve according to Section E.4, Trip System

Operation.

d. Increase turbine speed using the governor speed adjusting screw or knob on

the governor until trip speed is reached. The turbine should trip within 2% of

the trip speed setting on the turbine nameplate, and come to a complete stop.

e. If the turbine fails to trip at a speed 5% greater than the trip speed setting,

manually trip the turbine by pressing down on the trip lever. Refer to Section

K, Troubleshooting, to determine why the turbine fails to trip properly.

Optional construction may include an electronic overspeed trip system. Refer to

the certified drawings and the appropriate vendor instruction manual for

instructions on how to test the overspeed trip system.

Section F

Lubrication System

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F.1

General

Proper lubrication of turbine bearings and the governor is essential for long,

trouble-free service. Turbine oil must be clean, of the proper viscosity and

quantity, and maintained at the proper temperature. Oil levels should be checked

before starting the turbine and on a daily basis for turbines running continuously.

WARNING

Lack of lubricant or contaminated lubricant could result in

bearing failure. This could create sparks or hot surfaces, which

could ignite lubricant or flammable gasses.

CAUTIONS

Overloading the turbine drive shaft will cause the turbine to

slow down - possibly resulting in insufficient lubrication and/or

reduced function and damage to the driven equipment.

If the ambient temperature exceeds 110° F (43° C), cooling

water must be provided to the bearing housings to limit the

maximum temperature of the lubricating oil to 180° F (82°C). If

the ambient temperature falls below freezing a means must be

provided to maintain the lubricating oil in the bearing housings

to a minimum temperature of 130°F (54°C) and to prevent

cooling water from freezing and possibly cracking the bearing

housings.

Without immediate and constant oil feed, the heat generated by the shaft in the

turbine bearings, unless properly dissipated, can cause bearing failure. Oil ring

lubricated bearings receive immediate lubrication as the shaft begins to turn, so

long as the proper oil level is maintained in the bearing housings. With pressure

lubricated bearings, the lubrication system must be arranged such that oil fills the

supply lines and feeds the bearings when the shaft begins to turn.

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F.2

Lubrication Requirements

Lubrication requirements are a function of the turbine type, exhaust temperature

and required operating speed range. In many cases, several lubrication options are

feasible at a given set of operating conditions with the selected method determined

by the user.

Major oil companies produce satisfactory oil for turbine use. It is advisable to consult

with your oil supplier for specific recommendations. As a minimum, the selected oil

should meet the following:

(a) Properly refined highly filtered mineral oil.

(b) Maximum metal wetting ability and ability to prevent the formation of rust on

metal parts bathed in oil. High stability toward oxidation and corrosion resistance may be

accomplished by the use of rust and oxidation inhibitors, or as a result of a particular

refining process.

(d) Best possible ability to separate rapidly from water.

(e) Minimum tendency to oxidize or form sludge when agitated at actual operating

temperatures when mixed with air and water.

(f) Minimum tendency to emulsify or foam when agitated with water and/or air.

(g) High viscosity index. A fluid with a high viscosity index can be expected to

undergo very little change in viscosity with temperature extremes and is

considered to have a stable viscosity.

CAUTIONS

CLEANLINESS is ESSENTIAL for long and trouble free service

from BEARINGS and GOVERNOR. Care must be taken to

ensure that no foreign material enters bearing housings, the

governor, and constant level oilers or oil reservoirs when

performing maintenance, checking oil, adding oil or making

adjustments.

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Overloading the turbine drive shaft will cause the turbine to

slow down - possibly resulting in insufficient lubrication and/or

reduced function and damage to the driven equipment.

The bearings are made to precision limits on a production basis. When bearing

clearances become excessive, new bearings must be installed. Bearing clearances

may be considered excessive when they become approximately 0.004”/0.101mm over

the normal maximum clearance. (Refer to the turbine data sheets for normal running

clearance of your turbine.) The bearings are longitudinally split to permit their removal

and replacement with the shaft in place. Procedures for replacements are given in

Section L-6.

The recommended bearing temperature limits are as follows:

Metal Temp. Oil Temp.

°F / °C

Maximum Normal - Pressure Lube

Operating

220/104

180/82

Alarm

230/110

185/86

Shutdown

250/121

195/90.5

Maximum Normal - Ring Oiled

Operating

220/104

180/82

Alarm

265/129

185/86

Shutdown

270/132

195/90.5

Table F-1 Bearing Temperature Limits

F.3

Oil Ring Lubrication

The basic method of lubrication for SST turbines is oil ring lubrication. Carbon

steel oil rings running on the turbine shaft pick up oil from reservoirs in the

bearing housings. As the shaft and oil rings rotate together, oil flows from oil rings

onto the shaft, ultimately flowing into the bearings, providing lubrication. The

thrust bearing, located inside the shell of the steam end main bearing, receives its

lubricating oil from this same action. The oil level within bearing housings must

be maintained at a sufficient level to allow the oil rings to run in the oil. An oil

level that is too high results in oil leakage past the shaft seals. Oil rings cease to

rotate sufficiently when the shaft runs below

950 RPM, no longer providing

adequate lubrication. Therefore, the turbine should not be run at minimum

governor speeds less than 950 RPM unless for slow roll speeds of 500 RPM for

warm-up purposes.

SST frame turbines must have simple bearing cases, the ambient temperatures must

be below 110°F (43°C) and the cooling water supply must not exceed 100°F

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(38°C) to qualify for ring oiled lubrication. Heat deflectors and air maze breathers

must be used when the maximum operating exhaust temperature exceeds 400°F

(204°C).

Cooling water for the bearing case is recommended for all ring-oiled turbines.

Approximately 2 GPM of fresh water at 90°F (82°C) or less is required for cooling

the lubricating oil for each bearing housing. Cooling water is recommended when

the temperature of the bearing case cap exceeds 150°F (82°C). Maximum allowable

water pressure is 75 PSIG (517 KPAG). See Figure 25 for a typical bearing case

water piping schematic for ring oiled turbines.

The cooling water connections to the oil cooler are shown on the outline drawing

or oil piping diagram in Appendix A. The turbine data sheets specify the required

volume. The water outlet piping should be arranged to discharge into an open sight

drain where the operator can observe it. A water leg of at least six inches in height

should be placed in the outlet line adjacent to the cooler to assure the cooler being

kept full of water.

CAUTION

DO NOT RUN turbines equipped with oil ring lubrication at

speeds LESS THAN 950 RPM. The OIL RINGS WILL NOT

OPERATE CORRECTLY at these speeds, causing BEARING

FAILURE due to lack of lubrication.

The presence of oil in the constant level oilers does not

necessarily mean that oil in the bearing housings is at the

proper level.

Note: There are certain speeds and temperatures where Dresser-Rand

allows operation without cooling water. (Synthetic oil is required.)

F.4

Mist Oil System Lubrication

WARNING

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If the turbine is supplied with mist oil lubrication, oil mist could

escape from the bearing housing vents or oiler. If there is the

possibility that these could be ignited by equipment or

processes in the proximity of the turbine they should be piped

to a safe area.

The turbine may be lubricated by a facility mist oil supply. When a turbine

utilizes a system of this type, a diagram that shows turbine connections and piping

is provided in Appendix A.

F.5

Circulating Oil Cooling System

The circulating system is the next step up from the ring oil system with water cooling. This

system must be used when oil temperature in the bearing housings could exceed 180°F (82°C)

and/or the exhaust temperature exceeds 550°F (82°C). This elevated temperature is

normally caused by an increase in shaft/bearing rubbing speeds and/or elevated inlet or

exhaust steam temperatures being transmitted from the wheel casing to the bearing cases.

The circulating system is basically a ring lubrication system. The difference is that a

shaft driven direct drive pump which circulates oil out of the bearing cases for

additional cooling has been added. At higher exhaust temperatures, an external oil

cooler is added to the system.

The pump supplied with this system is a positive displacement gear type pump. It is

mounted on the shaft at the exhaust end of the turbine. The upper half of the exhaust

end bearing case serves as a housing for the pump. The same pump is used regardless

of turbine rotation. The pump may be mounted off the turbine shaft at the steam

end when design allows.

A standpipe or overflow port is located at each bearing case to maintain the correct

oil level.

F.6

Pressure Lubrication System

Force-feed (pressure) lubrication systems, mandatory on SST turbines operating

above 5000 RPM or when normal exhaust temperature is 650F (343C) or higher,

employ a positive displacement pump to draw oil from a reservoir which is then

cooled, filtered and delivered under pressure to the turbine bearings. The used oil

drains from the turbine bearing housings by gravity and flows back to the reservoir

to be reused.

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Force feed lubrication system reservoir/console assemblies must be located so that

the oil drain piping between the turbine bearing housings and the reservoir’s oil

return connection slopes a minimum of 0.5 inches per foot (40 mm per meter).

CAUTION

The oil drains must be free flowing at atmospheric pressure.

Under no circumstances should the oil drains be pressurized or

have a vacuum applied. Horizontal pipe runs should be sloped

continuously, at least 0.5 inches per foot [40 mm per meter],

towards the reservoir.

Refer to instructions from the lubrication system supplier.

CAUTION

All lubrication oil piping tubing, and system components, that

have not been pre-charged, should be flushed prior to

assembly. The assembled lubrication oil system should be

flushed prior to turbine initial start-up.

F.6.1

Design Parameters for Turbine Pressure Lubrication Oil Systems

SST turbines supplied with sleeve bearings and a standard ball thrust bearing

require:

Normal Oil Supply Temperature

= 120° F (49° C)

Normal Oil Supply Pressure

= 20 - 25 psig (137 - 172 kPag)

Oil Filtration

= 25 micron or better

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Bearing Cases

GPM

Heat Load

Steam End Exhaust End

Simple/Simple

300 BTU/Min

HiCap/Simple

500 BTU/Min

W/Ball Thrust

HiCap/Simple

1000 BTU/Min

W/Tilt Pad Thrust

Refer to Section F.12, Lubricating Oil Selection Guidelines, and to the certified

drawings in Appendix A for a description of the supplied hardware, the specific

lubricating oil requirements, the oil flow, and the heat load applicable to the

purchased equipment package.

CAUTION

SST turbines supplied with a tilting pad thrust bearing or

turbines sharing lubrication with a gear reducer or driven

equipment, will require additional oil flow and heat load

capacity and may require the use of special viscosity

lubricants. Refer to the certified drawings in Appendix A for a

description of the lubricating oil system requirements.

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F.7

Cooling Water to Bearing Housing Water Jackets

Tables F-1, Cooling Water Requirement, specifies when cooling water to bearing

housing water jackets is required. This requirement is based on the type of

lubrication system supplied with the turbine, the steam conditions, and the ambient

conditions. Refer to the certified drawings in Appendix A for specific cooling

water requirements for your turbines.

Lubrication Type

Cooling Water to Bearing

Cooling Water to

Housing Mandatory

Bearing Housing

Optional

Standard oil ring

Cooling water supply

temperatures must not

exceed 100°F (43°C)

Standard oil ring

with circulating oil

Force feed

Table F-1. Cooling Water Requirement

Cooling water for the bearing case for ring oiled turbines is recommended for all

ring-oiled turbines. Approximately 2 GPM of fresh water at 90°F (32°C) or less

is required for cooling the lubricating oil for each bearing housing. Cooling water

is recommended when the temperature of the bearing case cap exceeds 150°F

(65.5°C). Maximum allowable water pressure is 100 PSIG (690 KPAG).

Cooling of the bearing oil is accomplished by water jackets integral to the bearing

housings. Under severe service conditions such as high ambient temperatures,

partial load (high exhaust temperature) operation, and frequent shutdown (heat

soaking), the optional application of cooling water will assist in maintaining

recommended oil temperatures.

Cooling water should be piped into one of the lower connections on the bearing

housings and out from the upper connection on the opposite side. If

interconnection of water jackets on the two bearing housings is desired, connect

the outlet of the non-drive end bearing housing to the inlet of the drive end bearing

housing. Refer to Figure F-3, Cooling Water Piping with Interconnecting Pipe. All

unused bearing housing connections should remain plugged.

Valves should be included in the cooling water piping to control the flow of water

and allow it to be shut off. The ideal system would employ two valves—one

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upstream of the bearing housing, acting as a shut-off valve, and one downstream to

control flow. This arrangement ensures that water jackets are filled with water and

allows water to be shut off without disturbing the flow adjustment. If one valve is

used, it should be downstream of the bearing housings.

Figure F-1.Typical Bearing Case Water Piping Schematic for Ring Oiled

Turbines

Flow should be adjusted to maintain bearing oil sump temperature in the normal

range shown in Table F-3, Recommended Oil Sump and Bearing Temperatures.

Refer to the certified drawings in Appendix A for the location of cooling water

connections on bearing housings.

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Single stage ring oiled turbines require cooling water connections to the bearing

cases. See Figure F-3 for a typical bearing case water piping schematic for ring

oiled turbines.

Pressure Lube Turbines -- The cooling water connections to the oil cooler are

shown on the Outline Drawing or Oil Piping Diagram in Appendix A. The turbine

data sheets specify the required volume. The water outlet piping should be ar-

ranged to discharge into an open sight drain where the operator can observe it. A

water leg of at least six inches in height should be placed in the outlet line adjacent

to the cooler to assure the cooler being kept full of water.

F.7.1

Bearing Housing Cooling Water Requirements

Cooling water for bearing housings must meet the following specifications.

Flow Rate (per housing):

2 GPM (7.0 l/MIN)

Maximum Inlet Pressure:

100 PSIG (690 KPAG)

Maximum Inlet Temperature

90F (32C)

Water Quality:

Clean, non-corrosive

F.7.2

Governor Oil Cooling Water Requirements

Refer to turbine data sheets for water requirements. During operation, admit cooling water

as necessary to maintain oil temperature, out of cooler, between 90°F and 180°F (32°C

and 82°C).

F.8

Recommended Oil Sump and Bearing Temperatures

Table F-3, Recommended Oil Sump and Bearing Temperatures, lists the

recommended temperature ranges for the turbine bearing oil sumps and the turbine

bearings during normal operation. In addition, the table defines recommended

alarm and trip set points for optional instrumentation.

Oil Sump Temperature—

Bearing Temperature—

Operating Status

F

C

F

C

Normal Operation

180

220

104

Alarm

185

230

110

Trip

195

90.5

250

121

Table F-2. Recommended Oil Sump and Bearing Temperatures

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For turbines operating in an extreme environment, an optional thermostatically

controlled immersion heater may be provided in the main oil tank to heat the oil prior

to start-up and to maintain a suitable temperature during operation. If your turbine

has this equipment, a supplementary description and parts list is provided in Appendix

B. Operating procedures for this equipment are given in Section A-12.

When ambient temperature is approximately at the freezing point 32°F (0°C) or

below, the thermostat should be set at its maximum heat setting prior to startup. The

heater selected by Dresser-Rand is limited to approximately 250°F (121°C) so that

there is no danger of carbonizing the oil.

When oil reaches a temperature where it will flow smoothly, approximately 100°F

(38°C) it should be circulated through the oil system. If the oil tank is not equipped

with a thermometer, the temperature may be monitored as the oil leaves the system

cooler. The cooling water for the oil cooler should not be turned on until the turbine is

operating and the temperature of the oil leaving the cooler is approximately 120°F

(49°C). After oil pressure is established and stabilized throughout the complete system, the

turbine may be started, as described in the Starting Procedure. During operation, the

thermostat may be initially set at its minimum setting. Periodic checks of the oil tempera-

ture can determine the requirement for adjustment.

Governor Heater--When ambient temperature is approximately at the freezing

point, 32°F (0°C) or below, the thermostat should be set at its maximum heat setting prior

to startup. When the oil in the governor reaches approximately 90°F (32°C), the

turbine may be started and the thermostat set at its minimum heat setting. It should

be noted that precise temperature of the oil for normal operation of the governor is not

critical, provided that the oil temperature is within the range of 90°F to 180°F (32°C to

82°C).

CAUTION

Do not allow COOLING WATER to COOL OIL SUMP

TEMPERATURE TO BELOW 130F (54C), as this may

interfere with the action of the oil rings or cause

ATMOSPHERIC MOISTURE to CONDENSE in the oil

reservoir.

F.9

Constant Level Oiler

Turbines lubricated with oil rings typically are equipped with constant level oilers.

The purpose of these oilers is to maintain the correct oil level in the bearing

housings. When applicable, instructions for constant level oilers may be found in

Appendix B.

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F.10

Bearing Housing Oil Levels and Capacities

The following table shows the approximate oil quantities required to fill bearing

housings based on the SST turbine frame size. In addition, each constant level oiler

has a capacity of about 8 oz. of oil.

Frame Size

Steam End Capacity

Exhaust End Capacity

ALL SST’S

64 oz. (1.89 l)

Table F-3. Bearing Housing Oil Capacity

The following table shows the required oil levels that should be maintained by

proper adjustment of constant level oilers. The oil level gauge on the side of the

bearing housing indicates the oil level. A mark inscribed on the lower-half bearing

housing indicates the proper oil level. If the mark is obscured, refer to the

following table.

Distance Below Bearing Housing

Frame Size

Horizontal Split in Inches

SST Simple Bearing Case Steam End

3.25 (8.26cm)

SST Simple Bearing Case Exhaust End

2.875 (7.30 cm)

Table F-4. Bearing Housing Oil Levels

For hydraulic governor oil requirements, refer to the governor instruction manual

in Appendix B.

F.11

Maintenance/Oil Changes

Oil levels in turbine bearing housings, the governor and/or optional oil reservoirs

should be checked daily.

Low point drains in bearing housings and oil reservoirs should be checked weekly

for water.

Establish an oil change frequency based on oil tests. Otherwise, oil in bearing

housings and oil reservoirs should be changed monthly; or earlier, if there is reason

to believe that the oil has been contaminated with water, dirt, or by overheating.

CAUTIONS

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Lubrication System

The presence of oil in the constant level oilers does not

necessarily mean that oil in the bearing housings is at the

proper level.

CLEANLINESS is ESSENTIAL for long and trouble free service

from BEARINGS and the GOVERNOR. Care must be taken to

ensure that no foreign material enters bearing housings, the

governor, and constant level oilers or oil reservoirs when

performing maintenance, checking oil, adding oil, or making

adjustments.

For hydraulic governor oil requirements, refer to the governor instruction manual

in Appendix B.

F.12

Lubricating Oil Selection Guidelines

 Reference Table F-6 -- Sleeve Bearing Turbine, Lubricating Oil Selection

Guidelines.

 Reference Table F-7

- Ball Bearing Turbine, Lubricating Oil Selection

Guidelines

The importance of using a proper lubricant cannot be overemphasized. High

quality turbine oils are required. Dresser-Rand Steam Turbine Business Unit does

not recommend specific brands of oil. Turbine owners should consult reliable oil

suppliers regarding the proper selection of turbine oils. As a minimum, the selected

oil should be of premium quality rust and oxidation inhibited turbo-machinery oil,

which will readily separate from water and have minimum tendency to emulsify or

foam when agitated at actual operating temperatures. EP additives are not

recommended. Since the proper grade of lubricant may not be available locally, it

should be ordered in advance of start-up time. Comparisons between different

viscosity grading systems are shown in Table F-6, Viscosity Comparisons.

CAUTION

For SST turbines sharing a forced-feed lubrication system with

a gear reducer or driven equipment, refer to the certified

drawings in Appendix A for a description of the lubricating oil

requirements.

Viscosity Requirements

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VISCOSITY SSU

DESCRIPTION

VALUES @ 100°F

Range

Nominal

*Light Turbine Oil (LTO)

ISO VG 32

130-180

150

**AGMA 1 / SAE 10W {Med)

ISO VG 46

193-235

214

***AGMA 2 /SAE 20

ISO VG 68

284-347

315

****AGMA 3 / SAE 30

ISO VG 100

417-510

464

Typical Recommendations

* Pressure Fed Lubrication

** Pressure Fed Lubrication with Oil Rings Retained

*** Ring Oiled Lubrication or Units with Reduction Gear.

**** Mist Oil Lubrication or Units with Ball Bearings

Table F-5. Viscosity Comparisons

F.13

Air Purge of Bearing Housings

An air purge connection can be furnished as an option on the bearing housing for

the supply of low pressure, dry, filtered air or nitrogen. The positive pressure

(relative to atmospheric pressure) will prevent the intrusion of dust, moisture, and

other contaminants into the bearing housing. The supply pressure should not

exceed a 1-inch (25.4 mm) water column.

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Optional Gland Condensers, Eductors, and Ejectors

Section G

Optional Gland Condensers, Eductors, and

Ejectors

For some applications, optional ejectors, eductors or gland condensers may be

supplied with the turbine package for the removal and recovery of leakage past the

turbine shaft seals.

Motive flow is applied to the inlet of the educator or ejector, creating a slight

vacuum, which is applied at the turbine gland leak-off connections. The discharge

of the eductor, ejector and/or gland condenser is then typically returned to the

plant water system when the motive fluid is steam or a safe area when the motive

is fluid gas. These items normally ship loose for piping and installation by others.

Refer to the certified drawings and optional equipment manuals for details of any

items supplied with the turbine package.

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Optional Instruments and Controls

Section H

Optional Instruments and Controls

NOTE

Refer to Appendix B at the end of this manual for instructions

for accessory instruments and controls not manufactured by

Dresser-Rand.

H.1

Sentinel Warning Valve

If specified as an accessory (applies to turbines to be operated on steam only), the

turbine will be furnished with a sentinel-warning valve to alert the operator when

excessive pressure arises in the exhaust casing.

WARNINGS

The SENTINEL WARNING VALVE will ONLY WARN that

excessive pressure exists in the casing. It will NOT RELIEVE

THIS PRESSURE.

It is the USER’S RESPONSIBILITY to INSTALL A FULL-FLOW

RELIEF VALVE in the exhaust line between the turbine

exhaust casing and the first shut-off valve. This relief valve

should be sized to relieve the FULL AMOUNT OF STEAM

THAT THE TURBINE WILL PASS, in the event that the

exhaust line is blocked.

H.2

Pressure and Temperature Gauges

If specified as accessories, the turbine will be furnished with inlet and exhaust

pressure and/or temperature gauges. Inlet and exhaust gages must be connected to

the user’s inlet and exhaust steam piping just upstream and/or downstream of the

turbine inlet and exhaust flange connections as appropriate. Steam chest pressure

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SST Turbine Instruction Manual

gages may be connected to a “T” connection installed into the turbine steam chest

drain piping. Gauges are maintenance-free and require no attention.

H.3

Solenoid Trip

WARNING

If the turbine is equipped with a solenoid overspeed trip system

it will be activated electrically, hydraulically, pneumatically or

with a combination of these power sources. If the required

power source is not activated or fails, the over-speed trip

system will not operate. The turbine cannot be tripped by this

system.

When specified, the turbine can be supplied with a solenoid operated trip system

for remote trip functions. The supplied components may include a solenoid

actuator, or a solenoid valve and pneumatic actuator. The action of the actuator

striking the turbine trip linkage disengages the knife-edges in the turbine trip

linkage, causing the overspeed trip valve to close. Trip signals to the solenoid can

be automatically or manually transmitted. Electrical power (and for systems with

pneumatic actuators air pressure) must be available for the operation of the remote

trip functions. Turbines may also include optional mechanical or proximity type

limit switches, which may be wired to signal a “turbine tripped” condition. Refer to

the certified drawings and appropriate vendor instruction manuals for specifics of

the trip system supplied with the Dresser-Rand equipment package.

Refer to turbine data sheets to determine whether solenoid valve trips out turbine (opens)

in energized or de-energized mode. Make sure valve is closed before starting.

H.4

Other Optional Instruments and Controls

When specified by the customer, other optional instruments and controls can be

supplied. Refer to the certified drawings and appropriate vendor instruction

manuals.

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Start-Up and Operation

Section I

Start-Up and Operation

I.1

Warnings

The operator should read Sections A through H of this manual to become familiar

with the turbine before attempting to start and operate it.

WARNINGS

The surface temperature of the turbine and piping will become

that of the steam inlet temperature. This could exceed the

ignition temperature of some gasses. Therefore, if the turbine

is installed where explosive gasses could be present it is the

user's responsibility to insure that this does not create a

hazardous situation.

DO NOT START OR OPERATE this turbine unless the

INSTALLATION has been VERIFIED TO BE CORRECT and

all pre-startup SAFETY AND CONTROL FUNCTIONS have

been CHECKED.

DO NOT START OR OPERATE this turbine unless you have a

COMPLETE UNDERSTANDING of the location and function of

ALL COMPONENTS in the steam supply and exhaust

systems, including block and relief valves, bypasses, drains,

and any upstream or downstream equipment that may affect

the flow of steam to or from the steam turbine.

Should an explosion occur in the vicinity of the turbine it is the

user/installer’s responsibility to halt it immediately and/or limit

the range of explosive flames and explosive pressures to a

sufficient level of safety.

DANGERS

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NEVER WEAR NECKTIES OR OTHER LOOSE CLOTHING

while in the proximity of the turbine or auxiliary equipment.

These could be become entangled in the shaft, couplings,

linkage or other moving parts and cause serious injury.

Keep body parts

(fingers, hands, etc.) away from shaft,

coupling, linkage or other moving parts to prevent contact and

possible serious injury.

Wear proper eye protection when working on or around the

turbine.

WARNING

Never operate the turbine with the governor or governor

system disabled.

CAUTION

If the ambient temperature exceeds

110F (43C), cooling

water must be provided to the bearing housings to limit the

maximum temperature of the lubricating oil to 180F (82C). If

the ambient temperature falls below freezing a means must be

provided to maintain the lubricating oil in the bearing housings

to a minimum temperature of 130F (54C) and to prevent

cooling water from freezing and possibly cracking the bearing

housings.

DANGER

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NEVER BLOCK OR DISABLE THE TURBINE TRIP SYSTEM

OR ATTEMPT TO ADJUST OR REPAIR IT WHILE THE

TURBINE IS OPERATING.

WARNINGS

DO NOT START OR OPERATE this turbine unless you have a

COMPLETE UNDERSTANDING of the CONTROL SYSTEM,

the OVERSPEED TRIP SYSTEM, the drain and leak-off

systems, the lubrication system, and all auxiliary mechanical,

electrical, hydraulic and pneumatic systems, as well as the

meaning and significance of all monitoring gages, meters,

digital readouts, and warning devices.

When STARTING the turbine, be prepared to execute an

EMERGENCY SHUTDOWN in the event of FAILURE of the

GOVERNOR, OVERSPEED CONTROL SYSTEMS, linkage, or

valves.

The surface temperature of the turbine and piping will become

that of the steam inlet temperature. Personnel should wear

gloves and protective clothing to avoid burns.

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CAUTIONS

Overloading the turbine drive shaft will cause the turbine to

slow down - possibly resulting in insufficient lubrication and/or

reduced function and damage to the driven equipment.

Turbines should not be subjected to temperatures in a non-

running ambient condition of less than 20°F (unless special

LOW TEMPERATURE has been specified and low

temperature materials have been provided.

Do not operate the turbine above the Maximum Continuous

Speed or below the Minimum Allowable Speed as shown on

the nameplate, for sustained periods of time.

WARNINGS

The turbine should NOT BE OPERATED unless a properly

sized, functional, FULL FLOW RELIEF VALVE or other

overpressure protective device has been installed UPSTREAM

OF THE SHUT-OFF valve closest to the TURBINE EXHAUST

LINE.

VERIFICATION of proper FUNCTIONING and SETTING of the

OVERSPEED TRIP SYSTEM during initial start-up is

MANDATORY. This should be accomplished with the turbine

disconnected from the driven equipment.

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WARNINGS

Shown below are turbine noise levels that were measured at

three feet

(1 meter), while operating at a normal load and

exhausting to a positive back pressure. These noise levels are

not guaranteed and are published for informational purposes

only.

This noise data is based on test measurements that were

taken on similar equipment being operated on the factory test

stand, and have been extrapolated and/or corrected for

background noise as appropriate.

When the turbine is operated under actual field conditions,

noise generated in or by the piping, foundation, base plate,

couplings, driven equipment, background and other sources,

can add significantly to the turbine noise level and to the

overall noise levels in the area.

It is recommended that the equipment user assess the noise

level(s) of the completed installation and determine if additional

sound attention and/or hearing protection for operating

personnel is required.

Octave Band Frequency (HZ) - Expected Sound Pressure Levels

(dB - Ref. 2 x 10-5 N/m2)

Accoustic

125

250

500

Expected Overall dBA

Insulation

YES

Table I-1. Turbine Sound Level Data

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I.2

General

The following recommended start-up and operating procedures apply to the basic

turbine (ring-oiled, TG governor, without reduction gear). For information on any

optional equipment, refer to the appropriate vendor instruction manual in Appendix

WARNINGS

None of the recommended start-up and operating procedures

contained in this manual shall be construed in any way as

relieving the user of his responsibility for compliance with the

requirements of any regulatory body, or for the exercise of

normal good judgment in the start-up, operation, and care of

the turbine.

If a coupling guard is to be installed, refer to the coupling guard

manufacturer’s instructions to insure that it does not contact

the running shaft or coupling which could cause a spark that

could ignite hazardous gasses in the environment in which the

turbine is installed.

To ensure trouble-free operation, the turbine must be:

a. Cleaned thoroughly prior to start-up and kept clean at all times.

b. Properly lubricated at regular intervals.

c. Subjected to regular checks for the correct functioning of protective devices.

d. Regularly inspected and maintained according to a scheduled preventive

maintenance program.

e. Operated according to the procedures specified in this instruction manual.

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I.3

Turbine Installation and Start-Up Checklist

The following turbine installation and start-up checklist is provided as a guide on

the following pages. Although intended for use by Dresser-Rand servicemen, this

checklist is suitable as a guide for end-users as well.

Turbine Installation and Start-Up Checklist

I.3.1

Turbine Information

Customer

_________________

Location

______________

Serviceman

_________________

Customer Contact

______________

Start Date

_________________

Complete Date

______________

Nameplate Data:

Turbine

Driven Equipment

Serial Number

_________________

__________________

Rated Speed [RPM]

_________________

__________________

Overspeed Trip [RPM]________________

__________________

Power [HP]

_________________

__________________

Governor

Lube System

Manufacturer

_________________

__________________

Serial Number

_________________

__________________

Part Number

_________________

__________________

Application:

Use:

Continuous _______ Standby _________Autostart _________

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I.3.2

Site Information

Actual Steam Conditions:

Inlet press. (P1) ______Inlet Temp. (T1) ______Exhaust press. (P2) _____

Yes

Is the base provided level and adequate to support the turbine?

Is piping deadweight supported by hangers or supports?

Do inlet and exhaust flanges line up with piping flanges?

Does the steam inlet pipe have a top take-off from the main

header to minimize moisture induction?

Is there a piping run or dead leg beyond the take-off?

Have expansion joints been used?

Has the piping been blown out with steam (including exhaust

for backpressure units)?

Has inlet and exhaust piping been drained at low points or

trapped to avoid water legs?

Has a full-flow relief valve been installed in the exhaust system

upstream of the first shut-off valve? Setting? ___________

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I.3.3

Installation

Yes No

Is the turbine in good condition without signs of improper storage,

mishandling or shipping damage?

Are foundation and base plate securing bolts adequate?

Is the turbine properly secured to the base plate?

Has the base plate been grouted?

Was rust preventative removed from the shaft and other exposed

surfaces?

If the turbine was prepared for long-term storage, was the inside of

gland housings wiped clean and carbon ring sets installed?

If a sleeve bearing type turbine was prepared for long-term

storage, was the bearing and shaft journal surface wiped clean?

Were bearing housings flushed and drained with a light oil prior to

filling?

Are lubricating oil levels correct?

Turbine

Governor

Lubricating Oil Used:

Turbine --

Brand _______________

Type __________

Governor --

Brand _______________

Type __________

Is the coupling properly lubricated and free to oscillate by

hand?

Does the turbine rotate freely when turned by hand?

Do the oil rings rotate with the shaft?

Is the turbine rotation correct?

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Yes

Do the throttle valve, overspeed trip valve and associated linkage

move freely?

Does the Overspeed Trip lever reset easily and trip when operated

by hand?

Does the emergency weight move freely in the governor cup

assembly?

Has the lube system been site flushed?

Are lube oil return lines pitched to the sump?

Is there a Sentinel warning valve?

Setting? _________

Is the turbine adequately drained at all points?

Are water-cooling lines to the bearing housings properly installed?

Are there provisions for regulating cooling water flow?

Are steam leak-off connections piped correctly and unrestricted?

(I.e., with no valves, manifolds, water legs or pipe size reduction).

Does the user understand the following:

Overspeed Trip System operation?

Overspeed Trip Valve reset procedure?

Overspeed Trip exercising requirement and procedure?

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I.3.4

Start Up - Uncoupled

Drive shaft run out? ________ Driven equipment shaft run out? __________

Cold alignment method? (attach print out if available)

Rim & Face

( )

Reverse Indicator

( )

Laser

( )

Other

( )

RIM

FACE

Indicator mounted on _______________ coupling reading ________________

Turbine ___________________ inches low to driven equip.

Coupling Manufacturer _________________ Model ________

Yes No

Did governor operate properly?

Is the running speed satisfactory?

Trip speed checks #1 _______ #2 ________ #3 ________ RPM

Overspeed test witnessed by _______________________

Bearing oil temp (sump) Gov end _______ Drive end__________

Lube oil pressure to bearing ________ psig

Lube oil temp- Into Cooler ___________ Out ____________

Are protective devices operating properly?

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I.3.5

Start Up - Coupled

Actual Steam Conditions:

Inlet press. (P1) ______

Inlet Temp. (T1) ______Exhaust press. (P2) _____

Yes

Does the turbine operate at rated speed?

Speed variation? _____________ RPM

Does auxiliary equipment operate properly?

Is steam leakage within acceptable limits?

Vibration: (in/sec)

(mils) filtered unfiltered

(Indicate speed if mils are used __________ rpm)

Turbine

(Vert/Horiz/Axial)

Gov Bearing

___/__/___

Coupling Bearing

__/___/___

Driven equipment

Driven End Bearing

___/___/__

Non-Driven End Bearing

___/___/__

Are oil levels correct with no evidence of leakage?

Oil temp at discharge? Gov. End

_______ Drive End

________

Hot alignment method? (attach print out if available)

Rim & Face

( )

Reverse Indicator

( )

Laser

( )

Other

( )

RIM

FACE

Indicator mounted on _______________ coupling reading ________________

Turbine ___________________ inches low to driven equip.

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I.4

Start-Up Procedure

WARNING

Turbine installation, operation, repair and service must be

performed by EXPERIENCED PERSONNEL ONLY. Read and

understand this instruction manual before installing, operating,

repairing or servicing turbines.

I.4.1

Restoration of Turbine from Shipping Condition

The turbine was completely assembled, adjusted for proper operation, and tested

immediately prior to shipment. A quick reference check list of tasks to complete prior

to placing the unit into operation is as follows: (Storage information is provided at the

end of this section.)

 Unpacking and inspection

 Cleaning of shipping preservatives

 Selecting and preparing foundation

 Bearing inspection and seal oil baffle outside diameters

 Aligning turbine and driven machine

 Connect steam and exhaust piping

 Connect water piping

 Preparation for initial starting and start-up

We recommend that Dresser-Rand Service Representatives oversee the installation and

initial start-up of this steam turbine unit.

Before starting a turbine for the first time, or one that has been in storage, it is

important to have the bearing cases, shaft packing areas, and the governor parts

clean. Solvent may be used for this purpose.

(See Commercial Products for

Dresser-Rand Service List at the end of section

After factory testing, turbines are prepared for shipping and storage. The following

two sections describe activities to be performed prior to initial start-up.

I.4.1.1

Flushing/Filling of Bearing Housings

Before starting the turbine for the first time, open bearing case drains and allow

any residual oil to drain. Close the drains.

The oil recommended for permanent operation should now be added to the turbine

through the oil hole covers, until levels reach their respective permanent marks on

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bearing housings. Add oil as necessary to constant level sight feed oilers mounted

at each bearing case. Note that a low oil level may result in improper lubrication

and a high oil level may cause leakage past the seals and/or overheating.

Refer to Section F, Lubrication System, for oil recommendations.

I.4.1.2

Shaft Packing

If the turbine was prepared for short-term storage, then no additional steps are

required.

For turbines in long-term storage, the upper half of the turbine case must be

removed to gain access to the shaft packing and turbine rotor. The garter springs

and stop washers should be wiped clean to remove the rust preventative. Matched

carbon ring sets (shipped with the turbine) should be installed. Labyrinth and

carbon ring seals, the inside of the turbine case and all internal components should

be cleaned of the water-soluble preservative.

I.4.2

Initial Start-Up Procedure

The following recommended start-up procedure applies to the basic turbine (ring-

oiled, TG governor, without reduction gear). For information on any optional

equipment, refer to the appropriate vendor instruction manual.

On ring-oiled units, the oil should be warmed up to a viscosity such that the oil rings will

turn and pick up oil; this may be done by circulating hot liquid through the water jackets,

or by means of electric heating elements in the oil compartments. On units equipped with a

flood lubricating system the oil should be warmed up to a viscosity such that the oil

pump will pick up its prime; this may be done by means of a steam heating coil or an electric

heating element. If electric heating elements are used, they should be limited to

approximately 250°F. temperature, to avoid carbonizing the oil. After the oil is warmed up,

circulate some of the warm oil by means of a hand, motor or steam driven pump.

It may not be necessary to pre-heat the oil unless the ambient temperature is well below 32°

F, depending on the relationship between temperature and oil viscosity. Experience will

determine the temperature at which it is necessary to preheat the oil.

After heating the oil or determining that it does not require heating, start the unit in

the usual manner, taking special care that all drain valves are left open long enough

to drain all condensed steam from the steam line and the turbine. Turn the unit over

slowly for a short time, making sure that the oil rings are turning and/or the oil

pump is delivering oil.

Before connecting steam piping to the turbine for the first time, all piping should

be thoroughly blown out with steam to ensure that solid particles such as welding

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beads and rust are not carried along with the steam inlet into the turbine. Refer to

Section C, Installation. Thereafter, the following precautions must be taken:

Review warnings outlined in Section I.1. If this is the first time the turbine is

put in service, review the Installation Start-Up Checklist in Section I.3.

Check the driven machine and verify that it is ready to start.

Check oil levels in bearing housings and the governor.

Verify that the magnetic pick-up to signal gear clearance is correct

(if

supplied).

Verify that all valves downstream of the exhaust-isolating valve are open.

On condensing units, admit sealing steam to carbon ring glands.

For turbines supplied with gland leak-off connections, open the leak-off

atmospheric valve. Refer to Section C.3.12 , Gland Seal Intermediate Leak-

Off Piping-High Back Pressure Exhaust

Open the exhaust-isolating valve.

Open all hand-valves.

Drain all condensate from low points in the inlet steam line, from the casing or

low points in the exhaust steam line, and from overspeed trip and throttle

valve bodies. Drain valves may be left open while the turbine is started, to

allow condensate to drain as the turbine warms up.

If a cooling water system is used, admit cooling water to bearing housing

water jackets. Flow should be adjusted to maintain bearing oil sump

temperature in the normal range, as shown in Table F-3, Recommended Oil

Sump and Bearing Temperatures. Refer to Section F, Lubrication System.

If a gland seal condenser is used, admit cooling water. If a steam ejector or

water eductor is used, admit the motive flow.

Start the lubrication system, if applicable.

Verify that the overspeed trip valve is latched open, by raising the manual

reset handle.

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DANGER

NEVER BLOCK OR DISABLE THE TURBINE TRIP SYSTEM

OR ATTEMPT TO ADJUST OR REPAIR IT WHILE THE

TURBINE IS OPERATING.

o. Provide a means for measuring turbine speed, either with a tachometer or with

a stroboscope.

WARNING

Never operate the turbine with the governor or governor

system disabled.

p. Turn the governor-adjusting screw on the end of the governor fully

counterclockwise to the low speed position. Refer to Figure D-1, Woodward

Oil Relay Governor Features, for screw location.

q. Admit sufficient steam through the inlet-isolating valve to turn the turbine

over slowly (950 RPM minimum) and continue to operate at this speed until

the turbine is fully warmed. Close all drain valves when condensate no longer

drains. Some of the incoming steam will condense on the “cold” turbine walls.

CAUTIONS

DO NOT RUN turbines equipped with oil ring lubrication at

speeds LESS THAN 950 RPM. The OIL RINGS WILL NOT

OPERATE CORRECTLY at these speeds, causing BEARING

FAILURE due to lack of lubrication.

Do not operate the turbine above Maximum Continuous Speed

or below Minimum Allowable Speed as shown on the

nameplate, for sustained periods of time.

Listen for uneven running or vibration. Shut down and correct, if required.

Refer to Section I.5, Turbine Vibration Limits, when measuring shaft axial

displacement, shaft radial displacement, or bearing housing vibration.

Open isolating valve in the inlet steam line gradually, bringing turbine speed

up slowly until the governor takes control at the low speed setting. If the

governor has not assumed speed control by the time rated speed is reached,

shut down immediately and refer to Section K, Troubleshooting.

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For turbines supplied with gland housing leak-off connections, open the leak-

off isolation valve and close the leak-off atmospheric valve. Refer to Section

C.3.12, Gland Seal Intermediate Leak-Off Piping-High Backpressure

Exhaust.

u. Once speed control has been established, open the throttle valve by adjusting

the speed setting screw on the governor clockwise to bring the turbine up to

the required operating speed of the driven equipment.

v. Monitor turbine operation until stable operation is attained.

I.5

Turbine Vibration Limits

I.5.1

Shaft Displacement Measured with Proximity Probes

Radial Displacement:

When the turbine has been provided with provisions for radial proximity probes,

the turbine shaft has been burnished and degaussed at the probe locations to limit

the electrical and mechanical runout of the shaft. API 611 specifies that when the

turbine is brand new and operated on the factory test stand that the vibration level

must be at or below the “shop limit + runout”. Actual coupled, loaded field

conditions tend to be higher.

Radial displacement in any plane during coupled, loaded, field conditions should

be at or below the alarm level as shown in the figure below. If the level of

vibration increases to greater than the trip level, the turbine should be stopped and

the cause of the vibration identified and corrected.

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Wellsville SST Vibration Limits/Settings for API-

611 and Non-API Units

4.0

3.5

3.0

Shop Limit

2.5

2.0

Alarm Setting

1.5

Trip Setting

1.0

0.5

0.0

1000

4000

7000

MCOS (RPM)

Figure I-1.

Radial Shaft Displacement

Axial Displacement:

For turbines provided with standard ball thrust bearings, the shaft axial position is

typically not measured. Refer to tables B-1, Major Fits, Clearances, & Rotor

Balance Criteria

- SST, and B-2, Major Fits, Clearances, & Rotor Balance

Criteria - for shaft endplay.

Turbines provided with tilting pad thrust bearings are designed to have some axial

clearance between the active and inactive thrust faces known as float. When these

turbines have been provided with provisions for axial position probes, the Alarm

and Trip set points are specified in Table I-1, Axial Shaft Displacement Tilting Pad

Thrust Bearings. If the level of displacement increases to greater than the trip

level, the turbine should be stopped and the cause of the displacement identified

and corrected.

Note: For API 612 turbines the shop limit is 1.0 instead of 2.0.

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Turbine

Alarm

Trip

Model

ALL SST

+/- 17 mils

+/- 22 mils

MODELS

Table I-2. Axial Shaft Displacement Tilting Pad Thrust Bearings

I.5.2 Bearing Housing Vibration

When shaft proximity probes are not installed, the bearing housing vibration can be

used as an indirect measure of the shaft displacement.

API 611 and 612 specify that when the turbine is brand new and operated on the

factory test stand, the peak vibration measured on the bearing housing while it

operates at the maximum continuous speed shall not exceed 0.12 inches per second

[unfiltered] and

0.08 inches per second

[filtered]. When measuring bearing

housing vibration, the alarm and trip set points are specified in the table below. If

the level of vibration increases to greater than the trip level, the turbine should be

stopped and the cause of the vibration identified and corrected.

Bearing Housing Vibration [inches per second, unfiltered]

Turbine Model

Alarm

Trip

ALL SST MODELS

0.24

0.36

Table I-3. Bearing Housing Vibration

I.6

Testing the Overspeed Trip Mechanism

Refer to Section E.6, Testing the Overspeed Trip Mechanism.

I.7

Governor Speed Adjustment

Standard SST turbines are supplied with WOODWARD TG-type hydraulic

governors. Operating speed of the turbine is adjusted using the TG governor speed

adjustment screw, located in the cover plate of the governor. Refer to Figure D-1,

Woodward Oil Relay Governor Features, for adjusting screw location. The speed

adjustment mechanism is provided with sufficient internal friction to eliminate the

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need to externally lock the screw. A screwdriver, coin, or key may be used to

adjust speed, and only light torque is required to turn the adjusting screw.

Turning the adjustment screw clockwise increases the turbine speed setting.

Exercise care when increasing the speed setting, to ensure that driven machine

speed limits or trip speed are not inadvertently exceeded as a result of such

increases.

Turning the adjustment screw counterclockwise decreases the turbine speed

setting. Continuous governing below

1100 RPM for the low-speed governor,

below 2200 RPM for the medium-speed governor, or below 4000 RPM for the

high-speed governor is not recommended because governor oil pressure may not

be sufficient to actuate the governor valve.

Optional construction may include alternate governor configurations. Refer to the

certified drawings and appropriate vendor manual for complete description.

I.8

Governor Droop Adjustment

For WOODWARD TG-type hydraulic governors, droop is factory adjusted to

provide a no-load speed of approximately 106% to 110% of the full-load or normal

speed. If it becomes necessary to alter droop from this initial setting, follow

instructions in the Woodward governor manual.

Exercise caution whenever the governor is opened. The TG governor is a precise

hydraulic mechanism, and the entry of dirt or any other foreign material can cause

the governor to malfunction.

Optional construction may include alternate governor configurations. Refer to the

certified drawings and appropriate vendor instruction manual for complete

description.

WARNING

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GOVERNORS should NOT be DISMANTLED OR REPAIRED

by INEXPERIENCED PERSONNEL. Governors contain

powerful springs that could cause PERSONAL INJURY and

have delicate components which, if damaged, could result in

GOVERNOR FAILURE.

WARNING

FIELD CONFIGURABLE GOVERNOR

Any change to control limits, such as (but not limited to) speed,

overspeed trip, control logic, other than “tuning” (see governor

manual) requires the prior written approval of Dresser-Rand

Company to assure the safe operating limits are not exceeded.

Failure to comply may result in damage to property, serious

injury or death to personnel. Refer to the instruction manual for

detailed instructions.

I.9

Hand-valve Adjustments

SST turbines can, as an option, be fitted with up to three hand-valves (350 frame

turbines: 1; 500 and 700LP frame turbines: 2; and 700, 700H, and 700 HLP frame

turbines: 3). These hand-valves provide the operator with the ability to increase or

decrease the number of nozzles admitting steam to the turbine wheel.

The turbine will operate most efficiently when the pressure in the steam chest is at

a maximum (approximately 90% of line pressure). The highest chest pressure

occurs when the fewest number of hand-valves are open, which will allow the

desired operating speed.

To adjust hand-valves for maximum efficiency, proceed as follows:

With all hand-valves open and the normal load applied, adjust the governor to the

required operating speed. Beginning with the hand-valve farthest from the inlet

flange close one hand-valve at a time until the turbine speed falls off sharply. Then

reopen the last hand-valve that was closed. The speed should return to the required

value. If both hand-valves are closed and no sharp drop in speed occurs, leave both

hand-valves closed.

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Caution: When putting the unit into operation, do not close a hand-valve tightly

until the turbine is up to operating temperature and all parts are evenly heated. The

reason for this is that the material of the valve stem is subject to greater thermal

expansion than the turbine casing, and if the valve is closed tightly when cold, it

may lock the valve in the closed position making it difficult to open.

CAUTION

Do not leave any hand-valve partially open, as this may result

in steam cutting of the valve and seat. Hand-valves should be

completely open or completely closed. Turbine speed should

not be controlled by the hand-valves; this is the function of the

governor.

I.10

Shutdown

The following recommended shutdown procedure applies to the basic turbine

(ring-oiled, TG governor, without reduction gear). For information on any optional

equipment, refer to the appropriate vendor instruction manual.

After the unit is shut down in accordance with normal operating routine, special

care should be taken to be sure that all water is drained from the steam line, ex-

haust line, turbine casing, valves, oil cooler, etc. Pockets of water could cause

damage due to freezing, and could cause trouble during the next start-up.

Shutting down the turbine may be accomplished as follows:

a. Check shutdown instructions for the driven equipment.

b. Trip the overspeed trip lever manually.

b. Close the isolating valve in the inlet steam line.

WARNING

Do NOT USE the OVERSPEED TRIP VALVE as a permanent

SHUT-OFF VALVE.

d. For turbines supplied with intermediate gland housing leak-off connections,

open the leak-off atmospheric valve and close the leak-off isolation valve.

Refer to Section C.3.12, Gland Seal Intermediate Leak-Off Piping-High Back

Pressure Exhaust.

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If cooling water is used, turn off cooling water to the bearing housings after

the turbine has cooled down, unless on standby or automatic start.

CAUTION

WATER-COOLING JACKETS must be DRAINED if there is a

possibility of FREEZING TEMPERATURES.

Close the exhaust-isolating valve.

g. For condensing units, turn off sealing steam to carbon rings.

h. If a gland seal condenser is used, turn-off cooling water. If a steam ejector or

water eductor is used, turn-off the motive flow.

Open all condensate drains.

If the turbine is on standby service, or is to be shut down for an extended time

period, it should be started up, or at least turned over one or two times by

hand, once or twice each month to distribute oil to bearings, preventing rust.

k. Turbines in standby service, where bearing housing cooling water continues to

be supplied, must be checked periodically to ensure that moisture is not

condensing in the lubricating oil. Refer to Section F, Lubrication System.

WARNING

After operating the turbine, allow sufficient time for the turbine

to cool down prior to performing an inspection, repair or

maintenance function.

I.11

Restart Procedure

Before restarting the turbine, refer to Section I.1, Warnings.

I.11.1

Non-Condensing Turbines

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The following recommended procedure applies to the basic turbine (ring-oiled, TG

governor, without reduction gear). For information on any optional equipment,

refer to the appropriate vendor instruction manual.

Use the following procedure:

Check all oil levels. Fill lubricators as necessary. Start lube oil system, if

applicable.

Place any controls, trip mechanisms, or other safety devices in their operating

positions.

Open all drain valves on steam lines, turbine casing, and steam chest, and fully

open hand-valves, if furnished.

Open the turbine exhaust-isolating valve.

If cooling water is used, introduce cooling water to bearing housing cooling

chambers to prevent overheating. Cooling water flow should be adjusted to

maintain bearing oil sump temperature in the normal range, as shown in Table

F-3, Recommended Oil Sump and Bearing Temperatures.

If a gland seal condenser is used, admit cooling water. If a steam ejector or

water eductor is used, admit the motive flow.

Open the steam inlet isolating valve and bring the turbine up to desired speed.

Make necessary governor adjustments to attain desired speed as load is

applied to the turbine.

Close all drain valves when drain lines show the system is free of condensate.

Close hand-valves, as appropriate, to attain maximum efficiency.

Check bearing temperatures and overall operation for any abnormal

conditions.

Monitor turbine operation until stable operation is attained.

I.11.2

Condensing Turbines

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The following recommended procedure applies to the basic turbine (ring-oiled, TG

governor, without reduction gear). For information on any optional equipment,

refer to the appropriate vendor instruction manual.

Use the following procedure:

Check all oil levels. Fill lubricators as necessary. Start lube oil system, if

applicable.

Place any controls, trip mechanisms, or other safety devices in their operating

positions.

Open all drain valves on steam lines, turbine casing, and steam chest, and fully

open hand-valves, if furnished.

Turn on sealing steam to carbon rings. Open supply valve until a wisp of steam

flowing out of the outboard leak off is observed.

If a gland seal condenser is used, admit cooling water. If a steam ejector or

water eductor is used, admit the motive flow.

Open the turbine exhaust-isolating valve.

If cooling water is used, introduce cooling water to bearing housing cooling

chambers to prevent overheating. Cooling water flow should be adjusted to

maintain bearing oil sump temperature in the normal range, as shown in Table

F-3, Recommended Oil Sump and Bearing Temperatures.

For turbines supplied with intermediate gland housing leak-off connections,

open the leak-off atmospheric valve. Refer to Section C.3.12, Gland Seal

Intermediate Leak-Off Piping-High Back Pressure Exhaust.

Open the steam inlet isolating valve and bring the turbine up to desired speed.

Make necessary governor adjustments to attain desired speed as load is

applied to the turbine.

Close all drain valves when drain lines show the system is free of condensate.

Close hand-valves, as appropriate, to attain maximum efficiency.

Check bearing temperatures and overall operation for any abnormal

conditions.

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n. Monitor turbine operation until stable operation is attained.

I.12

Standby Operation

Turbines that are not running continuously are often in standby operation where

they must be ready to operate at any time with little or no advance notice. Turbines

in standby service must be capable of starting quickly and reliably in emergency

situations to prevent damage to large, costly systems, such as boilers or large

rotating machinery.

Turbines in standby operation present unique operational and maintenance

situations which must be understood and addressed. Listed below are the most

frequently encountered issues:

 Need to prevent collection of condensate in piping, valves or turbine casing.

Such condensate could slug or otherwise damage the turbine.

 Need to avoid thermal shock (casing and rotor stress) on rapid start-up.

 The need to start quickly with little or no intervention or effort by an operator.

 Avoidance of corrosion and fouling of control linkages, valves, glands,

packing, seals, etc., through lack of use.

 Degradation of lubricant by leakage, oxidation due to excessive heat, or

contamination from water, condensate, dirt or chemicals.

 Freezing of condensate or lack of lubrication due to extremely cold ambient

conditions.

Some methods and equipment employed to deal with the problems above are:

STEAM TRAPS - Steam traps are "smart valves" used in turbine drains and inlet

piping. Traps sense the presence of condensate and automatically open to allow it

to drain. When the condensate is drained the traps automatically close. Steam

traps are rated by pressure, temperature and flow. The amount of condensate

passed will vary, depending on the steam conditions and the steam piping design.

Steam traps should be valved to allow for maintenance and isolation. Manual

drains that bypass the trap are also recommended. When specifying steam traps

the highest pressure and temperature the trap might be exposed to should be taken

into account. This is often inlet pressure and temperature.

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AUTO START VALVE - A valve in the inlet steam piping which can be

automatically and remotely opened to start the turbine. The auto start valve

actuation speed should be sufficiently slow to minimize thermal shock to the

turbine and to allow sufficient time for the turbine governor to establish speed

control.

BYPASS VALVE - A small valve typically used to pass a small amount of steam

around an auto start or isolating valve to provide warming and in some instances

slow roll of the rotor.

IDLING NOZZLE - A special nozzle, usually piped separately via a bypass

valve, that is optimally chosen to provide warming and slow roll of the rotor with

minimal steam consumption.

SLOW ROLL - The steam powered slow turning of a turbine rotor, usually

several hundred RPM. Slow rolling a turbine will maintain the bearings, seals and

carbon rings free and operable. It provides warming that will reduce thermal shock

on start up and prevents freezing of condensate. Slow rolling maintains lubricant

moisture free and flowing. Some types of driven equipment cannot be slow rolled.

When a turbine is slow rolled special considerations may be required for

lubrication depending on turbine design, lubrication design, speed, exhaust

temperature and ambient conditions. Consult factory if slow roll operation is under

consideration.

EXHAUST WARMING - A means of warming a turbine by closing the inlet

block or auto start valve and opening the exhaust isolating valve. This is only

effective when exhaust pressure is greater than atmospheric. Precautions are

necessary to prevent introduction of foreign material into the turbine via the

exhaust steam and excessive exhaust pressure that might exceed the turbine's rated

exhaust pressure. No slow roll occurs. Condensate must be drained or trapped

prior to auto starting.

When operating on standby, the following practices and precautions are necessary:

 The turbine should be started periodically to verify that it is in proper

operating condition. This must include test and exercise of the overspeed trip

system.

 Steam traps should be checked periodically to insure that they are operating.

 An idling nozzle provides more efficient operation than a simple bypass valve

for slow roll.

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

To prevent excessive bearing temperatures, bearing housing cooling water

may be required during slow roll or exhaust warming operation.



Excessive cooling water flow during standby operation could cause

condensation to contaminate lubrication oil. Maintain bearing oil sump

temperature in the normal range, as shown in Table F-3, Recommended Oil

Sump and Bearing Temperatures.



Lubrication oil levels in the bearing housings and governor must be checked

periodically.



When a standby turbine is started, cooling water must be turned on if required.



Prior to start up, standby turbines must be drained of all condensate using

traps or manual valves.



The exhaust isolating valve on a turbine with auto start must be open at all

times to prevent over pressurization of the exhaust casing on start up.



When it is not possible to periodically operate or slow roll a standby turbine, it

should be periodically turned by hand.



If a turbine in standby operation is exposed to freezing temperatures,

provisions must be made to prevent damage and clogging of drains with

frozen condensate.

I.13

Auto Start Operation

If a standby turbine must be started quickly and automatically or from a remote

location, then the turbine must be equipped with an auto start valve and trapped

drains. The exhaust-isolating valve must be kept open.

Refer to Section I.12, Standby Operation, for additional information and

considerations.

Refer to Section C.3.14, Suggested Piping Schematics for Standard SST Turbines,

for additional information and considerations.

I.14

Manual Start Operation

If a standby turbine is to be started manually the inlet isolating valve is normally

closed, drains do not require steam traps and the turbine is put into service by

manually opening these valves.

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Refer to Section I.12, Standby Operation, for additional information and

considerations.

Refer to Section C.3.14, Suggested Piping Schematics for Standard SST Turbines,

for additional information and considerations.

I.15

Quick Start

In some applications, it is desirable to start up the turbine rapidly. Auxiliary oil

pumps and boiler feed pumps are often called upon to start quickly in emergency

situations. In such applications, condensate ingestion (slugging) and thermal shock

to the casing and rotor are concerns. Piping should be carefully designed and

trapped to prevent accumulation of condensate upstream on the inlet. Turbine

drains should be trapped as well. A small amount of inlet steam should be bled into

the inlet line to heat the turbine. Exercise care to ensure that the line, supplying this

warming steam, is not large enough to supply enough steam to drive the turbine.

Exhaust back pressure can be used for this purpose as well. Refer to Section I.12,

Standby Operation, and I.13, Auto Start Operation, and I.15.3, General, for

additional information.

I.15.1

Acceleration Rate

With steam turbine applications that are started with no load, the acceleration rate of a low

inertia rotating element can be so high that the control system response to close the

steam admission valve does not react prior to overspeed trip. This is particularly true

of the turbine generator sets, which may also require limited frequency variations in the

electrical system. In instances such as this, a ramp effect on governor valve closure may

be built into the control system.

I.15.2

Temperature Differential

On turbines with built-up rotors, the disc-to-shaft allowance tends to decrease to

unacceptable limits with a 200°F (93°C) temperature differential between the disc

and shaft. The probability of such a condition existing is greater at approximately five

minutes after start-up, rather than immediately at start-up. Loss of shrink fit can result in

axial or wobble movement of the disc on the shaft, possibly resulting in turbine

breakdown. The colder the unit at start-up, the greater the probability of the temperature

differential occurring. Since the utilization of forged discs in lieu of plate discs allows a

higher shrink fit, we normally recommend the customer consider using forged discs.

Operate in accordance with normal operating routine; except that in maintaining suitable

lubricating oil temperature and viscosity, it may be necessary to heat the oil instead of

cool the oil.

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On some types of turbine governors, a change in the oil viscosity has some effect on the

speed of the units; therefore, when operating a unit under varying oil temperature

conditions, it may be necessary to make manual adjustments on the speed governor.

I.15.3

General

The subject of "quick," "fast" or "automatic" start is not something new in the steam turbine

industry, nor has Dresser-Rand decreased its engineering standards for design of steam

turbine shafts, bearings, or shrink fit of discs to shafts.

In general, reliability and durability are compromised by quick starting a turbine and will

result in a shortened overall turbine life. Frequent quick starts are particularly severe on

bearings and rotating elements. The more rapid the acceleration rate, the higher are the

transient loads and the more severe are the loading effects.

Dresser-Rand single stage turbines with standard construction are suitable for start-up in

five seconds provided the following conditions are met:

1. The inlet side of the turbine steam line must be trapped.

2. Proper lubrication of bearings must be provided.

3. The inlet temperature of the steam shall not exceed 750°F (399°C).

4. The differential temperature between the inlet steam and exhaust steam shall not

exceed 350°F (177°C).

5. Back pressure shall be maintained on the casing during shutdown. (This in itself is not

a recommended operating condition due to possible wire cutting or carbon ring decay,

but will keep the casing warm.)

6. The operating speed of the turbine shall not exceed 6000 RPM.

7. The unit must be brought up under load.

In operating a turbine under the above conditions, the user must bear the responsibility

for bearing failure, loss of disc-to-shaft shrink fit, and carbon ring decay.

Dresser-Rand does not recommend quick starting turbines that are in locations

where the ambient temperature is less than 0F (-18C).

Units operating at very low ambient temperatures should be supplied with a

lubricating oil especially selected by a reputable oil company as being suitable for the

operating conditions. Special consideration should be given to insulating the entire

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unit, including the lubricating oil lines and the oil tank (on units equipped with a flood

lubricating system), to avoid excessive heat losses and excessive condensation of steam.

I.16

Function Check of Sentinel Warning Valve

A sentinel warning valve (when provided) is mounted on the turbine casing to

warn of excessive exhaust pressure. It is not a pressure-relieving device. The

following test of this valve can be performed when the turbine is not running and

should be carried out at least yearly. The sentinel warning valve should be set to

operate just before the full-flow relief valve starts to open.

The sentinel warning valve can be tested as follows:

a. Close the inlet-isolating valve.

b. Open the exhaust-isolating valve.

c. Latch the overspeed trip mechanism.

d. Open exhaust casing drain valve two turns.

e. Slowly open inlet isolating valve until a little steam flow is visible from the

exhaust casing drain.

Close the exhaust drain valve.

f. Slowly close isolating valve in exhaust line and observe pressure on a pressure

gauge mounted to the turbine casing, or in the exhaust line before the isolating

valve. The sentinel-warning valve should open at the pressure value stamped

on it.

CAUTION

DO NOT allow EXHAUST PRESSURE to EXCEED the

stamped setting value by more than 10 PSIG (69 kPag).

h. Relieve pressure in casing by rapidly and fully opening isolating valve in

exhaust line.

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Section J

Maintenance, Maintenance Schedule and Inspection

Schedule

J.1

Introduction

The Dresser-Rand SST Turbine is a high-quality prime mover that has been

carefully assembled and thoroughly tested at the factory. As with any machinery,

the turbine requires periodic maintenance and service. This section discusses

periodic maintenance requirements and procedures. Please refer to Section L,

Disassembly and Parts Replacement, for major service and overhaul instructions.

DANGER

DO NOT attempt to SERVICE, REPAIR, OR ADJUST A

RUNNING TURBINE, unless explicitly recommended in this

manual.

WARNINGS

MAINTENANCE PERSONNEL should be THOROUGHLY

FAMILIAR with the TURBINE, its CONTROLS and

ACCESSORIES, before attempting any maintenance or

service. Thorough familiarity with this manual is recommended.

If INTERNAL COMPONENTS of the turbine require REPAIR or

replacement, CLOSE, SEAL AND TAG INLET AND EXHAUST

ISOLATING VALVES and open all turbine drain valves,

thereby isolating the unit and preventing ACCIDENTAL

INTRODUCTION OF STEAM into it. Ensure that driven

equipment cannot rotate turbine shaft or uncouple the turbine

from the driven equipment.

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WARNINGS

When RESTARTING a turbine that was stopped for

maintenance or service, TESTING of the OVERSPEED TRIP

SYSTEM is MANDATORY prior to returning the unit to service.

After operating the turbine, allow sufficient time for the turbine

to cool down prior to performing inspection, repair or

maintenance functions.

J.2

Maintenance and Inspection Schedule

Maintenance requirements and the corresponding schedule will vary with the

application and service conditions. The following maintenance and inspection

guidelines are recommended for turbines operated under normal conditions.

Frequency

Maintenance or Inspection Procedure

Daily

Check oil levels in bearing housings and governor. Add oil if

required.

Check for smoothness of operation, unusual noises, or other

changes in operating conditions.

Check overall appearance of turbine system for steam, oil, or

coolant leaks, and for external damage.

Check bearing oil temperatures and pressures; check coupling

temperature.

WARNING

DO NOT attempt TO MEASURE COUPLING

TEMPERATURE while the turbine is RUNNING.

Table J-1. Suggested Maintenance and Inspection Schedule

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Frequency

Maintenance or Inspection Procedure

Weekly

Test the over-speed trip system. Refer to Section E, Overspeed

Trip System, for the test procedure. This exercise will not only

confirm operation of the trip system, but will prevent sticking of

the over-speed trip valve and linkage due to corrosion or steam

deposits.

Check operation of auxiliary oil pump (on turbines with this

equipment). See oil system schematic diagram in Appendix for

location of test valve.

Check operation of all low air/oil pressure shut down device(s).

Drain small quantity of oil from system and conduct an oil

analysis. Determine the need for an oil change. If system is

equipped with and oil filter element, change the element at the

time of the oil change.

Check throttle valve and linkage for freedom of movement.

Lubricate the governor lever connection.

Monthly

Check bearing housings for sludge, sediment, or water

(condensate). Flush and refill, as required.

Check that oil rings rotate freely and smoothly.

Check throttle and overspeed trip linkage for looseness, wear,

and freedom of movement. Check governor drive coupling for

wear

Yearly

Change oil in the Woodward TG governor.

Remove and clean the steam strainer. Replace every three years.

Inspect internal components of the throttle valve for wear.

Replace, if required. Replace valve stem seals.

Clean and inspect the over-speed trip valve. Replace worn parts.

Replace valve stem seals.

Thoroughly inspect the throttle linkage and overspeed trip

linkage for wear. Check governor drive coupling for wear.

Replace as required.

Table J-1. Suggested Maintenance and Inspection Schedule (Cont.)

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Inspect, clean, and flush bearing housings, oil reservoirs, and

Yearly

cooling water chambers.

Continued

Inspect carbon ring gland seals. Replace as required.

Check operation of the Sentinel warning valve.

Check alignment and foundation.

Remove top half of turbine casing and:

Clean scale and foreign material from wheels, buckets and

nozzles.

Check carbon rings for wear—remove, clean and reassemble

(refer to shaft packing section L.4.1 and L.4.2).

Check thrust bearing endplay.

Check calibration of all instrumentation.

Table J-1. Suggested Maintenance and Inspection Schedule (Cont.)

WARNING

Modification of, incorrect repair of, or use of non-DRESSER-

RAND repair parts on this turbine could result in a serious

malfunction or explosion that could result in serious injury or

death. Such actions will also invalidate ATEX Directive &

Machinery Directive Certifications for turbines that are in

compliance with those European Directives. Refer to Section M

-Replacement Parts/Factory Service

J.3

Major Inspection

Dresser-Rand recommends that the turbine be periodically shut down and

subjected to a major teardown and inspection. The frequency of this inspection will

depend on turbine service conditions, its maintenance history, the convenience of

scheduling a shutdown, the user’s experience with this or similar machines, or the

customer’s insurance company’s requirements..

J.4

Inspection Checklist

The following list summarizes parts that should be inspected during a major

inspection.

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Parts to be

Area to Be

Inspect for

Action Required

Inspected

Examined

Cracks, poor rivet

Consult manufacturer’s

Shrouds

heads

representative or factory.

File or grind smooth (Note:

Turbine and sector

removal of excessive material

blades

Corrosion, cracks,

Blades

will affect balance and blade

erosion

integrity. Consult manufacturer’s

rep. or factory if in doubt.)

Bearings

Surfaces

Wear, signs of

Replace if defective. Check

foreign matter,

condition of oil system.

scratches (pitting,

corrosion, galling,

excessive radial

play on ball

Drain oil & clean thoroughly.

bearings)

Fouling, scale,

Bearing Housings

Oil Reservoir

Refill with new oil.

rust, and water

Bearing housing

Labyrinth seal

Wear, dents in

Clean thoroughly.

oil seals

rings

surface, scale, dirt

Replace if badly worn or broken.

Breakage, wear,

Carbon rings

Clean. Carefully scrape high

high spots, dirt

spots.

Stainless steel

Glands

high velocity

Blistering, peeling

Replace shaft.

oxy fuel

Labyrinth

Wear, dents in

Clean thoroughly. Replace

steam seal

surface, scale, dirt

labyrinths if wear excessive.

teeth

Table J-2.

Inspection Checklist

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Parts to be

Area to Be

Inspect for

Action Required

Inspected

Examined

Remove with solvent and/or

Stem

Scale

crocus cloth.

Galling, wear

Replace.

Replace valve or cage, as

Valve and cage

Cutting, scaling

required.

Throttle valve

Wear, excessive

Seal sleeves

clearance, steam

Replace.

leakage

Remove obstructions and dents.

Cracks, dents, or

Replace if cracked or broken.

Steam strainer

obstructions

Determine cause of damage and

correct.

Connecting rod

ends, linkage

Wear, excessive

Replace worn components. Clean

pins, bushings,

Governor linkage

clearance/play,

with solvent and polish, if

Governor drive

corrosion

necessary.

coupling

Scale and boiler

Remove with solvent and/or

Valve Spindle

compound, dirt

crocus cloth.

Valve Spindle

Wear, excessive

clearance, steam

Replace.

Overspeed trip

Spindle

leakage

valve

packing

Wear, cutting,

Valve seat

Replace.

cracks

Pilot valve

Wear

Replace.

Trip collar

Binding, scale,

Disassemble and clean; inspect

assembly

corrosion, wear

for wear; replace as an assembly.

Linkage,

Overspeed trip

Foreign material,

Clean and inspect. Replace worn

connecting rod

system

wear, corrosion,

and defective parts. Adjust and

ends, bushings,

freedom of

confirm correct operation before

pins, reset

movement

returning turbine to service.

handle

Table J-2. Inspection Checklist (Cont.)

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Parts to be

Area to Be

Inspect for

Action Required

Inspected

Examined

Corrosion,

Replace packing; remove foreign

Stem and

Hand Valves

foreign material,

material from stem; replace stem

packing

wear

if pitted or worn.

Piping

Fouling, scale,

Clean thoroughly to remove.

reservoir

rust, water,

Filter oil to remove dirt. Drain

flaking paint

oil; remove access covers to clean

out any accumulated scale and

refill with new oil.

Pressure lube

system (when used)

Oil filter(s)

Increased

Replace filter element

pressure drop

Oil cooler(s)

Fouling and

Clean according to

corrosion on both

manufacturer’s instructions

oil and water side

Table J-2. Inspection Checklist (Cont.)

Refer to the certified drawings and the appropriate vendor manual for inspection

and maintenance requirements for optional equipment.

J .4.1. Protective Devices and Steam Cleanliness

RAPID CLOSING OF VALVES SUPPLIED WITH THE TURBINE IS ESSENTIAL

TO PROTECT AGAINST OVERSPEED AND POSSIBLE OTHER MECHANICAL

PROBLEMS. Such valves (governor valves, trip valves, trip throttle valves, etc.) must

close in fractions of a second; and deposits on valves, seats, stems, etc cannot impede

their movement. Deposits can form rapidly - as a result of improper water treatment

and/or entrainment of impurities in the steam supply.

The design clearance at the end of the governor controlled steam valve(s) and trip or trip

and throttle valve stems are required to minimize steam leakage from the turbine.

The stem clearances used by Dresser-Rand are based on many years of practical

experience and will prevent binding under normal temperatures and steam cleanliness.

HOWEVER, THE DEGREE OF STEAM CLEANLINESS TOLERANCE ON

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CONTROL VALVE AND TRIP VALVE COMPONENTS IS LIMITED AND

DEPOSITS MUST BE PREVENTED.

Steam cleanliness at the turbine flange is essential to reliable turbine operation.

Control of steam cleanliness is the responsibility of the turbine user and his system

operator. Cooperation with boiler manufacturers and water treatment specialists is

strongly recommended to maintain steam purity and cleanliness. Boiler operation must

prevent boiler compounds from being carried over to the steam turbine and causing

deposits on the valves.

DRESSER-RAND RECOMMENDS THAT THE TURBINE USER PERFORM

CAREFUL AND FREQUENT INSPECTION OF TRIP SYSTEM TO ASSURE NO

DEPOSIT BUILD-UP OCCURS that could cause the safety devices and valves to

become inoperative.

WE RECOMMEND THAT FREQUENT EXERCISING OF

(I.E. LIMITED

MOVEMENT/PARTIAL STROKING) THE CONTROL COMPONENTS BE

PERFORMED, especially if boiler carryover deposits may have occurred.

Exercising of the governor controlled valves may be performed by either a small load

change (where practical) or steam inlet pressure change. This can be accomplished by

choking the trip or trip and throttle valve. At the same time, the trip or trip and throttle

valve is exercised.

CAUTION: If the KW load on a turbine-generator cannot be reduced in the normal

manner, it indicates the possibility of unacceptable deposits on the control valve

components. STUCK CONTROL VALVES ARE A DANGER SIGNAL THAT THE

TRIP VALVE MAY ALSO BE STUCK.

UNDER THESE CONDITIONS IT IS IMPERATIVE THAT THE GENERATOR LOAD

NOT BE REMOVED UNTIL THE TRIP VALVE IS CLOSED. If the trip valve cannot be

closed by normal means, then other valves in the steam system must be used to cut off the steam

supply to the turbine. THE UNIT CIRCUIT BREAKER SHOULD NEVER BE OPENED

WHILE LOAD IS ON THE UNIT AND TRIP AND THROTTLE / GOVERNOR

VALVES ARE INOPERABLE. FAILURE TO FOLLOW THESE PRECAUTIONS

COULD CAUSE A SEVERE OVERSPEED WITH EXTREME DANGER TO THE

TURBINE AND OPERATING PERSONNEL.

J.5

Factory Service

Dresser-Rand maintains repair and rebuild facilities worldwide. In addition,

factory-trained servicemen are available for start-up, field service, and

troubleshooting. Consult your Dresser-Rand manufacturer’s representative or the

factory for service needs. Refer to Section M, Replacement Parts/Factory Service.

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J.6

Factory Replacement Parts

WARNING

Modification of, incorrect repair of, or use of non-DRESSER-

RAND repair parts on this turbine could result in a serious

malfunction or explosion that could result in serious injury or

death. Such actions will also invalidate ATEX Directive &

Machinery Directive Certifications for turbines that are in

compliance with those European Directives. Refer to Section M

-Replacement Parts/Factory Service

Dresser-Rand recommends that only Dresser-Rand-supplied parts be used in

Dresser-Rand turbines. The use of Dresser-Rand parts ensures that replacement

components are manufactured from the highest quality materials, to exacting

tolerances and specifications, thereby assuring efficient, long-lasting, and

maintenance-free operation, under service conditions that the turbine was built for.

Dresser-Rand and selected Dresser-Rand manufacturer’s representatives maintain

a supply of the most frequently requested spare parts for immediate shipment

worldwide. Parts requested less frequently can be manufactured quickly on an

emergency basis when required.

Your Dresser-Rand manufacturer’s representative can supply you with an

interchangeability list and a suggested stocking list of recommended spare parts for

your turbine or turbines, allowing you to stock spare parts at your facility. Refer to

Section M, Replacement Parts/Factory Service.

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Troubleshooting

Section K

Troubleshooting

K.1

Introduction

This section should be consulted when the turbine is not operating satisfactorily.

The table in Section K.2 lists the more common symptoms, probable causes, and

corrective actions in each case. If the problem cannot be completely remedied

using the table, refer all questions to your local Dresser-Rand manufacturer’s

representative, or to:

Dresser-Rand Company

Wellsville Operations, P.O. Box 592

Steam Turbine Business Unit

Wellsville, NY 14895-0592

www.dresser-rand.com

800-828-2818

585-596-3100

If corrective actions specified in items 5 through 8 of Section K.2 are attempted

and are not successful, and if the factory must be consulted, it is imperative to

provide exhaust pressure, speed, horsepower, and chest pressure. Chest pressure is

measured by installing a pressure gage in a hand-valve chamber drain hole and

reading the pressure with the hand-valve closed.

K.2

Troubleshooting

The following table lists common problems, possible causes, and the appropriate

corrective action of turbines that have operated successfully and develop problems

during the course of normal operation. Problems encountered during initial start-

up should be referred to the above contact information.

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No.

Symptom

Probable Cause

Corrective Action

Excessive

Misalignment.

Check the alignment when the turbine is hot.

vibration or

Disconnect coupling between turbine and driven

noise

machine; run the turbine alone. If the turbine

runs smoothly, there is either misalignment, a

worn coupling, or the driven equipment is at

fault. To check alignment, refer to Section C. If

the turbine drives a coupled gear, and the gears

run together at the top, allow for the pinion

running in the top of its bearing when under

load.

Worn bearings

Replace bearings. Refer to Section L.

Worn coupling to driven

Check condition of coupling. Replace if

machine.

necessary.

Glands fitted too tightly.

Tight carbon rings may cause vibration and

overheating. Refer to Shaft Packing Section for

proper clearance.

Loose wheels are extremely

Rotor should be returned to the factory to be

unusual, but may be caused by a

repaired.

runaway,

excessive

steam

temperature or shock loading.

Bent shaft

May be caused by hot bearings (see “Bearing

Heating and Wear”), tight glands (see “glands

Fitted too Tightly”), or mechanical damage.

Check the shaft runout near the center, as well

as at the shaft extension. Replace the shaft if

runout is excessive. Refer to Section L.

Unbalanced coupling to driven

Remove coupling halves and check for

machine

unbalance.

Unbalanced wheel

Check if turbine wheel has become unbalanced

due to fouling, over-speeding, or loss/damage to

shrouds or blades. Check if the turbine has been

standing idle for a long period without drainage

of the exhaust casing. Solid matter can build up

in the lower half of the wheel, causing

unbalance. The turbine wheel must be cleaned,

re-balanced or replaced. Refer to Section L.

Table K-1. Troubleshooting Guide

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Troubleshooting

No.

Symptom

Probable Cause

Corrective Action

Piping strain

Both the inlet and exhaust steam lines should be

properly supported to prevent strains from being

imposed on the turbine. Sufficient allowance

should be made for thermal expansion. Refer to

Section C.

Excessive end play

Check the axial position of rotor. If the endplay

exceeds 0.020”, replace thrust bearing. Verify

that coupling is cleaned and installed properly

so that excessive thrust is not imposed on

turbine from driven equipment.

Bearing

Improper lubrication

Refer to Section F to verify that the proper

Failure

lubricant is being used. Check oil periodically to

ensure that it is free of condensate and sediment.

Improper water cooling

When water-cooling is required, the water flow

must be adjusted to maintain bearing oil sump

temperature in the normal range, as shown in

Table F-2.

Wear and/or scratches in sleeve

Replace the sleeve bearings, drain oil reservoirs,

bearing

clean bearing housings, and add new oil. Inspect

journal surfaces.

Rough or untrue thrust collars.

Rough or untrue thrust collars on single-stage

(shoe-type bearing)

machines may cause rapid wear on thrust

facings of the sleeve bearings. This could

eventually increase thrust clearance to a point

where the turbine wheels would rub on the

guide or reversing ring. Rough or untrue collars

should be replaced or repaired at the first

opportunity.

Misalignment

Misalignment is one of the common causes of

bearing failure. Refer to remedies for

Misalignment under Vibration above.

Table K-1. Troubleshooting Guide (Cont.)

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No.

Symptom

Probable Cause

Corrective Action

Bearing fit

Ball bearings should fit on the turbine shaft with

a light press fit. Too tight a fit can cause

cramping; too loose a fit will allow the inner race

to turn on the shaft. Either condition results in

wear, vibration, overheating, and ultimate

bearing failure. Replace the shaft if worn below

recommended or specified size. Refer to Section

Excessive thrust

Verify that the coupling is clean and is installed

so that excessive thrust is not imposed on the

turbine from the driven equipment. If a fairly

high thrust is imposed on the turbine, consult the

factory to determine whether the thrust bearing is

suitable for the application.

Excessive belt pull

On belt driven units, verify that belts are not too

tight and consult the factory to determine

whether the turbine bearing is suitable for the

application.

Unbalance

Refer to Unbalanced Wheel under Vibration

above. Unbalance can cause excessive bearing

wear and early failure.

Excessive tension

The tension on the speed changer spring must be

spring

type

speed

sufficient to hold the governor lever firmly

changer.

against the governor spindle connection under all

conditions. Avoid any unnecessary loading on

this spring, as this would impose excessive load

on the thrust bearing.

Speed governor trying to

Leaking or stuck valve should be corrected, as it

close a leaking or stuck

constitutes a safety hazard, besides being

governor valve.

detrimental to the thrust bearing. Excessive wear

is also imposed on the governor ball thrust

bearing.

Heavy slugs of water in

This condition can be avoided through proper

the steam.

boiler control. Damage to the thrust bearings

and wheels will result from water slugs.

Table K-1. Troubleshooting Guide (Cont.)

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Troubleshooting

No.

Symptom

Probable Cause

Corrective Action

Rust

Rust may develop on bearing surfaces when the

turbine is improperly stored; refer to Section A

for details. Rust may also develop when the

turbine is out of service for long periods, without

receiving proper attention; refer to Section J.

Excessive steam

Dirt under rings

Steam leaking under carbon rings may carry

leakage past shaft seals

scale or dirt, which can foul the rings. Remove

rings and clean, as per Section L. The rings

should be free to float axially, and the

downstream face of the ring must seat perfectly

against the smooth, true and clean surface of the

adjacent carbon ring spacer.

Shaft scored

The shaft surface under carbon rings must be

smooth to prevent leakage. Factory-supplied

shafts are hard chrome plated. Polish minor shaft

imperfections or replace the shaft, per Section L.

Worn or broken carbon

Replace with new carbon rings, as per Section L.

rings

Although there are

3 segments per ring, the

entire ring must be replaced. Carbon rings

should have a slight clearance on the shaft when

cold, as carbon expands much less with heat than

steel.

Corroded, worn or dirty

Steam will leak past the carbon ring partition

partition plate surfaces

surface if dirt, corrosion or scoring prevents a

good seal. Polish sealing surfaces. Replace

partitions (when used) if badly worn or pitted.

Refer to Section L.

Labyrinth steam seal

Refer to Sections L and Supplemental Data for

improperly installed

proper installation procedure.

Worn or broken labyrinth

Replace labyrinths. Refer to Sections L and

steam seal teeth

Supplemental Data for proper installation

procedure.

Excessive

exhaust

Packing cases are designed for a pre-determined

pressure

backpressure. Excessive backpressure causes

leakage, which is a common cause of water in

the lubricating oil.

Excessive joint sealing

When replacing carbon rings, use joint

compound in gland

compound sparingly. Excess compound may

housing

foul carbon rings and gland housing sealing

surfaces.

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Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Leak-off pipe plugged

Verify that all steam and condensate can

discharge freely. Refer to Section C.3.10.

Oil leaks past laby seal

High oil level

Reduce the oil level to coincide with marks on

bearing housings. Refer to Section F.

Scratched or rough shaft

Polish the shaft under the laby seal and install a

under laby seal

new laby seal. Refer to Sections F and L.

Seal improperly installed

Refer to Sections F and L for proper installation

procedure.

Shaft vibration

Refer to all causes under Vibration above. Install

a new laby seal, if necessary, as per Sections F

and L.

Insufficient

power

Too many hand-valves

Open additional hand-valves. Refer to Section I

(turbine does not run at

closed

for proper adjustment of hand-valves.

rated speed)

Oil relay governor set too

Refer to Section D for speed adjustment and

low

speed range limits.

Inlet steam pressure too

Check the steam pressure at the turbine inlet and

low or exhaust pressure

exhaust pressure close to the exhaust casing,

too high

using accurate gauges. Refer to the turbine

nameplate for intended steam conditions. Low

inlet pressure may be the result of auxiliary

control equipment such as a pump governor

which is too small, improper piping size,

excessive piping length, etc.

Load higher than turbine

Determine the actual load requirements of the

rating

driven equipment. In some instances, modifying

a few components can increase available turbine

power. Consult the factory for this

determination.

Throttle

valve

not

Close the main inlet valve and disconnect throttle

opening fully

linkage. The valve lever should move freely

from fully open to fully closed. If not,

disassemble the throttle per Section L and free

up the assembly, as required.

Low governor oil level

Refill—Refer to Section D.

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Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Nozzles plugged

Remove the cover and rotor and inspect nozzle

openings. Remove nozzle block to clean nozzles

as required.

Steam strainer

Remove all foreign matter from steam strainer.

Refer to Section L.

Speed increases

Throttle valve not closing

Refer to governor valve not opening fully under

excessively as load is

fully, governor responds

Insufficient power above. Free the sticking valve

decreased

slowly due to worn parts

and inspect all pivot points in linkage for signs

or sticking.

of sticking or binding or excessive wear.

Throttle valve and valve

Remove governor valve, as per Section L. Check

seats cut or worn

valve and seats for wear or steam cutting.

Replace if necessary.

Excessive speed

Governor

droop

An increase in the internal droop setting will

variation

adjustment

reduce speed variation or hunting. Refer to

Droop Adjustment in the Woodward Governor

Manual.

Governor lubrication

Low governor oil level, or dirty or foamy oil

may cause poor governor operation. Drain, flush,

and refill governor with the proper oil. Refer to

Section D.

Governor valve assembly

Disassemble the governor valve per Section L.

friction

Inspect for free and smooth movement of all

moving parts. If required, polish throttle valve,

governor valve and bushing assembly, and valve

stem with very fine Emery cloth. Inspect valve

stem for straightness and for build-up of foreign

material. Replace components as required.

Governor valve seal

Check the valve stem for free and smooth motion

friction

through the throttle bonnet assembly. If friction

or binding occurs, disassemble throttle bonnet

assembly and repair or replace seal components,

as necessary. Refer to Section L.

Rapidly changing load

Rapidly changing load can sometimes cause

governor hunting. Consult the factory, providing

details of the application.

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Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Governor knife edges

These must be replaced if badly worn. There is

worn.

no effective repair for these parts.

Lost motion so the

This is usually the result of excessive wear at the

governor valve does not

pivot points in the linkage. Bearing in the

always follow the motion

linkage should be replaces, as well as the linkage

of the governor.

pins.

Light load and high inlet

In some cases, where the turbine provides a large

steam pressure

amount of reserve power and the inlet steam

pressure is quite high, there is a tendency for

excessive speed variation. Try operating the

turbine with additional hand-valves closed. This

condition can sometimes be corrected by

replacing the governor valve and bushing

assembly. Consult the factory, providing details

of the application.

Sluggish governor

Governor

droop

Reduce the droop setting. Refer to Droop

response.

adjustment

Adjustment in Woodward Governor Manual.

Turbine carrying very

Open necessary hand-valves to increase

heavy load, little reserve

horsepower.

power.

Slow start-up

General

Refer to all causes under Insufficient power

above.

High starting torque of

Obtain the required starting torque from the

driven equipment

driven equipment manufacturer and consult the

factory to determine whether the turbine is

overloaded in the application.

Governor not operating

Governor valve travel

Refer to Governor valve not opening fully under

restricted

Insufficient power above.

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No governor control on

If the speed increases continuously on start up

start-up

and the governor does not close the throttle

valve, the governor pump may be installed in the

wrong direction of rotation. Also verify that the

installed governor operates in the proposed speed

range. If pump rotation appears to be the

problem, remove the governor according to

Section L. Replace it with a governor of the

proper rotation. Refer to the Woodward

Governor Manual for instructions on changing

governor rotation or consult the factory.

Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Governor oil leakage

General

Isolate the source of leakage. If leakage is at the

cover plate gasket, drain plug or oil breather,

replace the gasket and/or tighten these

components to stop the leak. If leakage occurs at

terminal shaft seals or the drive shaft seal,

replace the governor per Section L.

Drive assembly vibration

Vibration of the turbine shaft or governor drive

coupling may induce leakage at the governor

drive shaft seal. Refer to all causes under

Excessive vibration or noise above. Inspect and

tighten the coupling per Section L. Check for

misalignment or bent turbine or governor shaft.

Overspeed trip actuates

Overspeed trip set too

The over-speed trip should be set at

on load changes

close to turbine operating

approximately

16% OR 21% above the rated

speed

speed, depending on the NEMA rating (D or A)

of the governor. Refer to Section E.

General

Refer to all causes under Speed increases

excessively as load is decreased above.

Light load and high inlet

Refer to Light load and high inlet steam pressure

steam pressure

under Excessive speed variation above.

Overspeed trip actuates

Excessive vibration

Replace the trip lever and/or trip latch if latching

at normal operating

surfaces are worn, after resolving cause of

speed

excessive vibration.

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Trip speed setting too

If the turbine consistently trips at or close to the

low

same speed, the trip setting may be set too low.

The setting should be approximately 16% OR

21% over rated speed, depending on the NEMA

rating (D or A) of the governor. Refer to Section

E for adjustment procedures.

Overspeed trip does not

Trip speed setting too

If the overspeed trip has not actuated when the

actuate at overspeed

high

turbine reaches 25% above rated speed, the trip

speed setting may be too high. The setting should

be approximately

16% OR 21% over rated

speed, depending on the NEMA rating (D or A)

of the governor. Refer to Section E for

adjustment procedures.

Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Overspeed cup

Examine mechanism. Verify that it is clean and

mechanism

in good working order, and that the trip weight

can be moved easily by a small screwdriver or

similar tool.

Improper adjustment or

The trip valve must be tested frequently. To test

poor condition of the

the valve, trip the over-speed mechanism by

tripping

mechanism,

hand. Make sure the trip valve closes promptly

springs or latches.

and stops the turbine.

Excessive friction in trip

These serious faults should be corrected by

valve spindle packing.

cleaning, repairing or replacing parts so that this

Scaling,

wear,

important safety device can operate effectively.

mechanical damages in

trip valve or its supports.

Governor does not trip at

Gain access to and examine the overspeed

or near the proper speed.

governor. Make sure it is clean, in good order,

and that the emergency weight can be easily and

freely moved in the governor cup by a small

screwdriver or similar tool. Adjust as described

in Section VI. Test the unit by actually over-

speeding. If it still does not trip at the proper

speed, adjust the setting of the emergency

governor as required. If low oil pressure trips,

solenoid trips, high back pressure trips, or similar

devices are provided, check them at the same

time.

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Overspeed trip valve

Overspeed trip valve may be frozen in place due

unable to close

to steam deposits, corrosion, or other

contaminants. Disassemble and clean valve

assembly according to Section L.

A broken steam strainer, or other foreign objects,

may interfere with proper seating of the over-

speed trip valve. Disassemble and inspect

combination valve according to Section L.

Excessive steam

Load

greater

than

The operator, after acquainting himself with the

consumption.

realized.

correct hand valve use on the turbine, must make

sure the correct combinations of hand valves are

open for various loads.

Table K-1. Troubleshooting Guide (Cont.)

No.

Symptom

Probable Cause

Corrective Action

Speed below normal.

Check the steam pressure and backpressure. Make

sure the governor is fully opening the valve. Check

and see if the hand valves are in use as designed.

Too many hand valves

This situation gives a turbine excessive capacity

open.

which requires throttling by the governor valve to

maintain the proper speed. This is inefficient and

uses more steam than necessary. Close the hand

valves to eliminate throttling.

Steam pressure low, or

These conditions must be corrected if the turbine is

exhaust pressure too

to carry a full load. Better boiler control will

high.

provide steam pressure correction. Horsepower

goes down as exhaust pressure goes up over

designed pressure.

Steam is wet, or the

This condition not only causes loss of power, but

super- heat low.

also is dangerous since it causes excessive erosion

on the nozzles and blades. Adjust steam conditions

as per manufacturer's recommendations.

Worn or damaged

This adversely affects the efficiency of the turbine.

nozzles and blades.

Nozzles and/or blades should be replaced or

repaired at the earliest opportunity.

Table K-1. Troubleshooting Guide (Cont.)

Refer

the certified drawings and the appropriate vendor manual for

Troubleshooting Guidelines for optional equipment.

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Section L

Disassembly and Parts Replacement

L.1 Warnings/Cautions

DANGERS

DO NOT attempt to ADJUST, REPAIR, DISASSEMBLE OR

MODIFY this turbine WHILE IT IS IN OPERATION, unless such

action is expressly described in this instruction manual.

NEVER DISCONNECT INLET OR EXHAUST FLANGES of the

turbine without first isolating the turbine from inlet and exhaust

systems by CLOSING AND TAGGING ISOLATING VALVES

and de-pressurizing the turbine casing and steam chest by

opening all drains. Open connections not protected by isolating

valves should be covered with blank flanges.

Do not remove any covers, guards, gland housings, drain

covers, etc. while the unit is operating.

WARNING

After operating the turbine, allow sufficient time for the turbine

to cool down prior to performing inspection, repair or

maintenance functions.

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CAUTION

Do not operate the turbine above Maximum Continuous Speed

or below the Minimum Allowable Speed as shown on the

nameplate, for sustained periods of time.

WARNINGS

Modification of, incorrect repair of, or use of non-DRESSER-

RAND repair parts on this turbine could result in serious

malfunction or explosion that could result in serious injury or

death. Such actions will also invalidate ATEX Directive &

Machinery Directive Certifications for turbines that are in

compliance with European Directives. Refer to Section M -

Replacement Parts/Factory Service

NEVER REPLACE ANY ORIGINALLY SUPPLIED BOLT WITH

A SUBSTITUTE BOLT OF UNKNOWN or LESSER GRADE.

DO NOT MIX BOLTS during disassembly. Failure to use the

proper grade bolt could result in SERIOUS FAILURE of

pressure-containing components. Refer to Section B, Technical

Data.

MAINTENANCE PERSONNEL should be THOROUGHLY

FAMILIAR with the TURBINE AND ITS CONTROLS AND

ACCESSORIES, before attempting any maintenance or

service. A complete reading of this manual is recommended.

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CAUTIONS

If the turbine is equipped with a throttle valve manufactured by

a party other than Dresser-Rand refer to Appendix B for

installation, operation, repair, and maintenance instructions.

If the turbine is equipped with a trip valve manufactured by a

party other than Dresser-Rand refer to Appendix B f this

manual for installation, operation, repair and maintenance

instructions.

WARNINGS

Dresser-Rand turbine components are manufactured from a

variety of materials, depending on steam pressure, steam

temperature, speed and horsepower. Before replacing any

components, be absolutely certain that the REPLACEMENT

PART was INTENDED for use in the TURBINE UNDER

REPAIR.

When RESTARTING a turbine after repair, maintenance or

rebuilding, always TREAT the turbine as if it were a NEW

TURBINE being started for the first time. Refer to Section I,

Start-Up and Operation.

CAUTION

CLEANLINESS is ESSENTIAL for long, trouble-free service

from BEARINGS and the GOVERNOR. Take care to ensure

that no foreign material enters bearing housings, the governor

or constant level oilers when performing maintenance, checking

oil, adding oil, or making adjustments.

L.2

General

This section describes disassembly and parts replacement for Dresser-Rand SST

turbines. Some parts of a SST turbine can be replaced in the field using instructions

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presented in this section, if qualified personnel and facilities are available. If not, it

is recommended that a Dresser-Rand service representative be employed to make

the field repairs, or that the turbine be returned to the factory, where a complete

inspection can be made. If returned, the factory will prepare an estimate of the cost

of cleaning the turbine, replacing parts as required and restoring the turbine to

practically new condition. After factory repair, the turbine will be no-load tested

and preserved just as a new machine would be. A factory-rebuilt turbine receives a

new turbine warranty.

L.3

Turbine Case Upper Half Removal and Replacement

The upper half of the turbine case must be removed to gain access to the shaft

packing and turbine rotor. NOTE: Make sure that the steam inlet and the exhaust

line shut-off valves are shut before starting work.

In some applications, special bolting is supplied. Consult the factory before

replacing or torquing the bolts in the turbine.

WARNING

NEVER REPLACE THE ORIGINALLY SUPPLIED BOLT WITH

A SUBSTITUTE BOLT OF UNKNOWN or LESSER GRADE.

DO NOT MIX BOLTS during disassembly. Failure to use the

proper grade bolt could result in serious failure of pressure-

containing components.

If the applicable bolt torque is not specified in the Assembly/Disassembly section,

the following table may be used as a guideline.

The procedure for removing and replacing the case upper half is specified below.

Refer to the following figures:

L-1

Case Upper Half Removal

L-2

Flange Bolt Torque Sequence

L-3

Flange Bolt Torque Sequence, 700H Casing

L-9

Hand Valve Assembly

M-8

Case, Rotor and Mechanical Gland Seals

M-9

Case, Rotor and Carbon Ring Gland Seals

Turbine Cover Removal (Upper half of the exhaust casing)

a. Remove the bolts from the horizontal flange of the turbine.

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b. Break horizontal joint (cover/case mating surfaces) by inserting jacking bolts

in holes provided at the four corners of the cover flange.

c. Using a hoist and center eyebolt at the top of the upper case half, lift turbine

cover slowly and carefully so as to avoid damaging the rotor inside. Refer to

Figure L-1 Case, Upper-Half, Removal.

Place turbine cover on a clean surface so as to prevent damage to its sealing

face.

Figure L-1. Case Upper-Half Removal

Turbine Cover Replacement (Upper half of the exhaust casing)

a. Inspect the interior of the turbine cover and exhaust casing. Remove any

foreign material.

b. Remove all old sealant from both surfaces of the horizontal joint. Do not file,

gouge or scratch these surfaces. If the surfaces are warped, steam-cut or

otherwise damaged, a leak-tight seal may not be possible.

c. Apply joint sealant after cleaning the split surface on case and cover. Apply a

light coat of Hylomar (recommended by Dresser-Rand) to sit for 15 minutes

before putting the cover on the case.

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Approximate

location if string or

tape is used

Steam End

Figure L-2. Flange Bolt Torque Sequence

TORQUE — STUDS AND STUD BOLTS

TORQUE VALUES BELOW ARE TO ATTAIN APPROXIMATELY 45,000 PSI STUD

STRESS

SIZE

THREADS PER INCH

TORQUE (FT.•LBS.)

0.500

0.625

106

0.750

188

0.875

303

1.000

455

Table L-1. Applied Bolt Torques for Case Flange Bolts

1. After the joint is properly prepared, the threads that protrude through the flange

should be lightly coated with a thread lube/anti-seize compound.

2. Tighten all nuts in the sequence shown to approximately 50 percent of the

specified torque for the first pass and to the full torque value for a second and

third pass.

3. Check and, if required, retighten after the turbine is at normal operating

temperature using the sequence shown.

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d. Apply anti-galling thread lubricant to the threads of all bolts.

e. Lower turbine cover onto lower half of casing. Ensure the cover seats evenly.

Install and tighten the horizontal flange bolts in accordance with Figure L-2,

Flange Bolt Torque Sequence and Table L-1, Applied Bolt Torques for Case

Flange Bolts. Tighten all nuts uniformly to approximately 10% of the specified

torque; then using the illustration as a guide, tighten to full torque. Check and

re-tighten after turbine is at normal operating temperature, using the sequence

shown.

g. For the SST 700H casing, tighten all bolts in sequence indicated in Figure L-3

to level 1, and then repeat the sequence at level 2, and then at level 3 indicated

in table L-2.

Figure L-3. Flange Bolt Torque Sequence, Series 700H

BOLTS

#1-#24

#25-#38

FIRST PASS

2601-FT-LBS

2001-FT-LBS

SECOND PASS

5251-FT-LBS

4001-FT-LBS

THIRD PASS

5251-FT-LBS

4001-FT-LBS

Table L-2. Applied Bolt Torques Case Flange Bolts

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Dresser-Rand. Instruction Manual for Single Stage 350, 500, and 700 Frame Steam Turbines (2011) - page 2