CHAPTER THREEOPERA TIONINTRODUCTIONTurbine applications differ widely; therefore, operating procedures must be tailored to each particular installation. Instructions in this chapter provide a recommended procedure for the initial start-up and serve as a guide for establishing routine operating procedures.Operating personnel must review this technical manual to become familiar withthe safety precautions and operating procedures for YR Turbines. Particularattention should be directed to the WARNINGS, CAUTIONS, and NOTES inthis chapter.For location of parts described in the following text, refer to the Steam Chest Assembly and Typical YR Turbine Assembly figures in Chapter 4.STEAM SUPPL YSteam should be free from moisture and preferably superheated. A receiver type separator with ample drains should be provi ded upstream of the shut-off valve to prevent water from entering the turbine. When a separator is not provided, a continuous drain must be connected to the lowest point of the steam inlet piping.CAUTIONIf continuous drainers are on the steam piping orturbine drains, check frequently to verify that properoperation is maintained. Failure to drain water fromsteam lines or turbine casing may result in erosion,thrust failures, and/or poor performance.The steam strainer protects the turbine from large particles of scale, welding beads, etc. This strainer does not protect against abrasive matter, boiler compound, acids or alkaline substances, all of which may be carried over in the steam. These substances may corrode, erode or form deposits on the internal turbine parts, thus reducing efficiency and power. Feed water treatment and boiler operation must be carefully controlled to verify a supply of clean steam for long-term satisfactory operation.Chapter 3OperationSAFETY PRECAUTIONS1. Do not operate the turbine if inspection shows that the rotor shaft journals and/or shaft packing case areas are corroded.2. Before starting, verify the rotor rotates freely by hand and that it is not rubbing any stationary parts.CAUTIONDo not rotate shaft until lubrication has been applied.Rotating the shaft without lubrication may result indamage to the rotor shaft and bearing liners .If rubbing or vibration occurs during operation,immediately shut down the turbine, investigate andcorrect the cause.3. Verify all piping (steam, water, air) and electrical connections are made before operating the turbine.4. Verify that all valves, controls, trip mechanisms and safety devices are in good operating condition.-WARNING-UNDER NO CIRCUMSTANCES SHOULD THE TRIPV ALVE BE BLOCKED OR HELD OPEN TO CAUSE THETRIP SYSTEM TO BECOME INOPERA TIVE.OVERRIDING THE TRIP SYSTEM AND ALLOWING THETURBINE TO EXCEED THE RATED (NAMEPLATE) TRIPSPEED MAY RESULT IN FATAL INJURY TOPERSONNEL AND EXTENSIVE TURBINE DAMAGE.IN THE EVENT THE TRIP SYSTEM MALFUNCTIONS:IMMEDIATEL Y SHUT THE TURBINE DOWN BYCLOSING THE INLET STEAM SHUT-OFF V ALVE.5. Before initial start-up, after major maintenance and after an extended shutdown, do not leave the turbine unattended at any time until proper operation with load has been Demonstrated.PREPARING THE TURBINE FOR INITIAL START-UPNOTEComplete installation work before attempting to operateturbine. (Refer to Chapter 2.)1. Disconnect the coupling between the turbine and driven machine. Turbines driving through reduction gears can remain coupled to the gear and operated together.2. Disconnect the steam inlet piping at the turbine and blow out the line with the supply steam to remove any foreign material from the pipe. Use targets for determination of cleanliness. (Refer to NEMA SM23 section 8.4 for additional details.)3. Verify the steam strainer is clean and properly installed in the steam chest inlet flange. Connect the pipe to the turbine as a permanent joint. Adjust piping hangersto eliminate any unacceptable strain on the turbine in cold and hot conditions. Piping strains must be calculated in agreement with current NEMA SM23 standards.4. If operating a condensing turbine, clean rust preventative compound from internal turbine surfaces.CAUTIONRust preventative compound will foul surfacecondenser tubes if not removed before operating theturbine.NOTEAs an alternative to manually cleaning the turbine internalsto remove rust preventative compound, the turbine may berun for several hours while exhausting to atmosphere.5. Remove bolting from the steam end bearing cap and the exhaust end bearing cap. Lift the caps approximately 1 inch (25 mm) and pry out the top bearing liners torelease the oil rings (if supplied). Remove the bearing caps and roll out the bottom bearing liners by lifting up on the rotor and rotating the bearing liners toward the positioning lugs. Clean and inspect the bearing liners. Keep the steam and exhaust end bearing liners separate.CAUTIONAttempting to remove the bearing caps without pryingout the top bearing liners can distort the oil rings.Distorted oil rings will not rotate and fail to provideadequate lubrication, resulting in bearing failures.NOTETurbines with Class 3 (or higher) rotors are pressurelubricated and may not have oil rings supplied. (Refer tothe Turbine Operating Data page located in the front of thismanual to determine the rotor class.)6. Clean the rotor shaft journals, locating bearing, and the bearing housings with clean,lint free rags. If turbine is equipped with Kingsbury type thrust bearings, removethrust bearings and clean; reassemble per Supplement 03-91, located in Chapter 8 Accessories.7. Lift the weight off the rotor and roll the bottom bearing liners into place. Make certainthe positioning lugs on the liners are correctly seated in the bearing housing locatinggrooves.CAUTIONVerify that the steam end and exhaust end bearingliners are not interchanged.8. Place the top bearing liners on the shaft journals. If the turbine is ring oiled, positionoil rings in the slots of the top liners. Flood the rotor locating bearing, shaft journals,and bearing liners with oil. (Refer to Chapter 5 for proper oil levels and lubrication requirements.)9. Replace the bearing caps. Verify that the positioning lugs on the top liners engagethe grooves in the bearing caps. Apply a very thin coat of sealant to the split line.Insert the dowel pins and tighten all bolts.10. If supplied, review the driven machine instruction manual for pre-start inspection procedures.11. Inspect the governor linkage. For specific details on preparing the governor for start-up, refer to Chapter 6, and the governor manuals located in Chapter 8 Accessories.12. Verify that all lube oil piping has been installed and the lubrication system has been flushed.CAUTIONIf the turbine is pressure lubricated, verify orifice plugsare installed at the bearing housings. If orifice plugsare not installed, oil leakage will occur.13. Verify free movement and clearances of the trip system. Manually activate theoverspeed trip pin to verify the ov erspeed trip system is functional.14. Fabricate a clamp or other blocking device to secure the coupling sleeve (if supplied) to the hub while operating the uncoupled turbine.NOTEUse a balanced adapter to secure balanced gear typecoupling hubs during uncoupled operation.15. Verify that the exhaust relief valve is installed correctly and operates at the correct pressure.-WARNING-THE TURBINE SHOULD NOT BE OPERATED UNLESSTHE A TMOSPHERIC RELIEF V ALVE OR OTHERPROTECTIVE DEVICE HAS BEEN INSTALLEDBETWEEN THE TURBINE EXHAUST CONNECTIONAND FIRST EXHAUST ISOLATION V ALVE (ORCONDENSER, IF THE TURBINE IS A CONDENSINGTURBINE).THE A TMOSPHERIC RELIEF V ALVE OR OTHERPROTECTIVE DEVICE MUST BE DESIGNED FOR FULLRELIEF OF THE MAXIMUM STEAM FLOW THROUGHTHE TURBINE WITHOUT EXCESSIVE EXHAUSTPRESSURE.FAILURE TO INSTALL THIS TYPE OF DEVICE MAYRESULT IN SEVERE EQUIPMENT DAMAGE AND/ORSEVERE INJURY OR DEATH TO PERSONNEL.16. Fill oil lubricators (if ring oiled) or oil reservoir (if pressure lubricated) with proper oil. (Refer to Chapter 5 for details.)17. Inspect and test all controls, alarms, trips and relief valves. Calibrate and install all instrumentation.18. Roll the shaft by hand through several revolutions, checking for possible binding or rubbing. Any sign of binding or rubbing should be thoroughly investigated before attempting to start the unit.19. If automatic controllers or regulators are supplied, do not enable during initial start-up; use only after the general operation of the equipment has been determinedsatisfactory.INITIAL START-UP1. Open drain valves to drain water from the steam inlet piping, turbine casing, steam chest, and the exhaust piping.2. V erify that the lube oil temperature is greater than 70°F (20°C).3. If turbine is ring oiled, check that oil lubricators are filled. If turbine is pressure lubricated, prime the oil pump(s) and verify that the oil reservoir is filled to the correct level. Start the auxiliary oil pump (if supplied) and circulate the lubricating oil. Check the oil piping for leaks and that oil is being delivered to the bearings.4. Adjust the governor speed setting to minimum speed. (Refer to “Governor Operation” in Chapter 6.)5. Completely open the overload hand valves (if supplied). For further details review the section on overload hand valves in this chapter.6. V erify that the trip valve is closed and open the turbine exhaust isolation valve.7. V erify proper oil pressure is present (pressure lubricated with auxiliary oil pump only).8. Latch the trip valve resetting lever.9. Commission the eductor/ejector (if supplied).NOTEWhen ejectors/eductors are used on packing case leakofflines, the customer can turn on at their discretion.However, care must be taken to prevent steam fromblowing out of packing cases along the turbine shaft, whichmay contaminate oil in bearing housings.10. Close the intermediate leakoff valve (BYRHH and optional on BYRH turbines) and maintain closed position until leakoff pressure builds to line pressure.11. For condensing turbines, close all drain valves and commission main condenser according to manufacturer’s instructions.12. Slowly open the main steam isolation valve until the turbine reaches approximately 500 rpm.CAUTIONSteam should not be admitted to the turbine casing bypartially opening the main steam isolation valve while the rotor is stationary. This condition will cause uneven heating of the turbine rotor and casing, which may result in a distorted casing, bowed rotor shaft or other related problems.13. For condensing turbines, adjust the sealing steam supply valve to permit a slight amount of steam to be discharged from the packing case leakoff drain lines. Apressure of 3 to 5 psig (0.20 to 0.35 bar) is usually sufficient sealing steam pressure. However, care must be taken to prevent steam from blowing out of the packing casesand along the turbine shaft.CAUTIONIf sealing steam is allowed to leak into the bearinghousings, the lubricating oil may becomecontaminated and form sludge and foam. To preventthis condition, adjust the sealing steam accordingly.14. Immediately verify operation of the trip valve by striking the trip lever. Close the main steam isolation valve as the turbine speed decreases.15. Latch the resetting lever and slowly open the main steam isolation valve to bring the turbine back to 500 rpm. If the turbine is ring oiled, remove the inspection plugs fromthe bearing caps and check to be sure the oil rings are rotating. Verify proper oilpressure is present (pressure lubricated only). Monitor the speed carefully during thelow speed operation.CAUTIONDo not leave the turbine unattended at any time duringthe initial start-up.16. Introduce cooling water to bearing housing cooling chambers or oil cooler (if supplied) to prevent overheating. (Refer to Chapter 5 [Table 5-3], for recommended bearing operating temperatures.)17. Listen for any unusual noises, rubbing, or other signs of distress in the turbine. Do not operate if any of these conditions are present. Monitor the turbine for signs of overheating and excessive vibration. (Refer to the Troubleshooting Guide in Chapter7 for possible causes and corrective actions for abnormal conditions which mightoccur.)18. When the turbine is thoroughly warmed up and low speed operation is determined tobe satisfactory, close the overload hand valves (if supplied).19. For non-condensing turbines, close all drain valves provided no signs of condensateare visible at all drain lines.20. Proceed with wearing in of the carbon rings (if supplied). (Refer to Turbine Operating Data Sheet located in the front of this manual, for steam seals supplied with this unit.)a. Gradually increase turbine speed to 1000 rpm and hold for 10-15 minutes.b. Reduce turbine speed to 500 rpm and hold for 5-10 minutes, allowing shaft tocool.c. Increase turbine speed by 1000 rpm and hold for 10-15 minutes.d. Reduce turbine speed by 500 rpm and hold for 5-10 minutes, allowing shaft tocool.e. Continue increasing turbine speed by 1000 rpm and decreasing by 500 rpm untilrated operating speed as shown on the turbine nameplate is achieved.NOTEThe stepped start up procedure (wearing in of the carbonrings) must be done for the first 2 or 3 turbine starts, orafter installation of new carbon rings. Failure to do so mayresult in improper wearing in of carbon rings and causeexcessive packing case steam leakage.21. After the turbine is operating, closely observe oil pressures and temperatures. For condensing turbines, adjust sealing steam to maintain 3 to 5 psig (0.20 to 0.35 bar).22. Verify the overspeed trip by temporarily overriding the governor to actuate the overspeed trip mechanism. (Refer to Control System, Chapter 6, for specific detailson overspeeding the turbine.)CAUTIONDo not operate the turbine more than 2% above therated trip speed listed on the turbine nameplate. If theoverspeed trip does not operate within 2% of thedesignated speed, shut the turbine down and makenecessary adjustments as described in Chapter 4,Overspeed Trip System.Three consecutive, non-trending trip speeds within the required range (refer toTurbine Data sheet located in the front of this manual) must be recorded to verify safe trip system operation. After a turbine trip and the speed decreases by 15-20% ofrated speed, the resetting lever may be relatched and the turbine brought back up in speed.-WARNING-DURING TESTING OF THE MECHANICAL OVERSPEEDTRIP, THE FOLLOWING GUIDELINES MUST BEADHERED TO:A. LIMIT PERSONNEL TO THE MINIMUM NUMBERREQUIRED TO CONDUCT THE OVERSPEEDTESTS.B. THE MAIN STEAM ISOLATION V ALVE TO THETURBINE MUST NOT BE FULL Y OPENED. ITSHOULD ONL Y BE OPENED AS FAR ASNECESSARY TO REACH THE TRIP SPEED.C. DURING THE TEST, TRAINED PERSONNEL MUSTOPERATE THE MAIN STEAM ISOLATION V ALVETO THE TURBINE.D. TWO SOURCES OF SPEED INDICATION AREPREFERRED. BOTH SHOULD BE OF KNOWNACCURACY AND CURRENT CALIBRATION.23. Continue operating the turbine for approximately one hour, while carefully monitoring bearing temperatures, turbine speed, vibrations levels, and listening for any unusual noises.24. Shut down the turbine upon satisfactory completion of the initial run. (Refer to “Turbine Shut Down” at the end of this chapter.)25. Couple the turbine to the driven equipment. If the turbine is used with a speed reduction gearbox or other special equipment, follow all instructions pertaining tothose particular items.ROUTINE START-UP1. V erify proper oil pressure is present (pressure lubricated only).2. Open drain valves to drain water from the steam inlet piping, turbine casing, steam chest, and the exhaust piping.3. V erify that the lube oil temperature is greater than 70°F (20°C).4. If turbine is ring oiled, check that oil lubricators are filled. If turbine is pressure lubricated, prime the oil pump(s) and verify that the oil reservoir is filled to the correctlevel. Start the auxiliary oil pump (if supplied) and circulate the lubricating oil.5. Completely open the overload hand valves (if supplied). For further details, review the section on overload hand valves in this chapter.6. V erify that the trip valve is closed and open the turbine exhaust isolation valve.7. Latch the trip valve resetting lever.8. V erify proper oil pressure is present (pressure lubricated with auxiliary oil pump only).9. Commission the eductor/ejector (if supplied).NOTEWhen ejectors/eductors are used on packing case leakofflines, the customer can turn on at their discretion.However, care must be taken to prevent steam fromblowing out of packing cases along the turbine shaft, whichmay contaminate oil in bearing housings.10. Close the intermediate leakoff valve (BYRHH and optional on BYRH turbines) and maintain closed position until leakoff pressure builds to line pressure.11. For condensing turbines, close all drain valves and commission main condenser according to manufacturer’s instructions.12. Slowly open the main steam isolation va lve until the turbine reaches approximately 500 rpm.CAUTIONSteam should not be admitted to the turbine casing bypartially opening the main steam isolation valve whilethe rotor is stationary. This condition will causeuneven heating of the turbine rotor and casing whichmay result in a distorted casing, bowed rotor shaft orother related problems.13. For condensing turbines, adjust the sealing steam supply valve to permit a slight amount of steam to be discharged from the packing case leak off drain lines. A pressure of 3 to 5 psig (0.20 to 0.35 bar) is usually sufficient sealing steam pressure. However, care must be taken to prevent steam from blowing out of the packing casesand along the turbine shaft.CAUTIONIf sealing steam is allowed to leak into the bearinghousings, the lubricating oil may becomecontaminated and form sludge and foam. To preventthis condition, adjust the sealing steam accordingly.14. Immediately verify operation of the trip valve by striking the trip lever. Close the main steam isolation valve as the turbine speed decreases.15. Latch the resetting lever and slowly open the main steam isolation valve to bring the turbine back to 500 rpm. If the turbine is ring oiled, remove the inspection plugs fromthe bearing caps and check that the oil rings are rotating. If the turbine is pressure lubricated, verify proper oil pressure is present.16. Introduce cooling water to bearing housing cooling chambers or oil cooler (if supplied) to prevent overheating. (Refer to Chapter 5 [Table 5-3] for recommended bearing operating temperatures.)17. Listen for any unusual noises, rubbing, or other signs of distress in the turbine. Do not operate if any of these conditions are present. Monitor the turbine for signs of overheating and excessive vibration. (Refer to the Troubleshooting Guide in Chapter7 for possible causes and corrective actions for abnormal conditions which might occur.)18. For non-condensing turbines, close all drain valves, provided no signs of condensate are visible at all drain lines.19. Adjust governor to attain desired speed as load is applied to the turbine. (Refer to “Control System”, Chapter 6). Close ov erload hand valves as required by turbine operation. (Refer to the “Unit Outline” in Chapter 10, Technical Drawings, foroverload hand valve settings.)20. After the turbine is operating, closely observe oil pressures and temperatures. For condensing turbines, adjust sealing steam to maintain 3 to 5 psig (0.20 to 0.35 bar).OVERLOAD HAND V ALVES (Optional)Overload hand valves are used sometimes to control the steam flow through an extra bank of nozzles. These valves can serve three functions:a. When closed, the valves will provide more efficient turbine operation at reduced load with normal steam conditions by reducing the nozzle area and also reducing thesteam flow.b. In some applications, overload hand valves are used to develop the required powerby opening the valves when steam conditions are less than normal (such asencountered during boiler start-up).c. Sometimes overload hand valves are used to develop increased power for meeting overload requirements with normal steam conditions.(Refer to the “Turbine Outline” in Chapter 10, Technical Drawings, for overload hand valve positioning versus turbine power, speed and operating steam conditions.) For the bestefficiency and speed control, open only the overload hand valves required for the actual steam conditions present and power required.TABLE 3-1OVERLOAD HAND V ALVESTurbine Frame Size Number of TurnsAYR 7BYR, BYRIH 9CYR, CYRH 12DYR, DYRH, DYRM, DYRN 12DYR, DYRH, DYRM, DYRNwith 8" inlet14BYRH, BYRHH 12NOTEOverload hand valve must be positioned either completelyopen or completely closed. Turning the stemcounterclockwise approximately 1½ turns will open thepilot valve. (Refer to Table 3-1 for the correct number ofturns required to completely open the main valve disk.)Open all overload hand valves during start-ups to verifyeven heating of casing and prevention of valves binding inthe casing. The overload hand valves can be completelyclosed if not needed when governor control is reached.CAUTIONOperation of the overload hand valve, in anythingother than completely open or completely closedposition, can cause valve failure and possible internaldamage to the turbine.For further information on Auto-Overload hand valves (if supplied), refer to Supplement 02-86-R1, in Chapter 8.TURBINE SHUTDOWNCAUTIONBefore shutting down turbine, verify that the governorsystem and trip system are in proper working order. Ifthe operational integrity is uncertain, shut off the mainsteam isolation valve to stop the turbine.1. Reduce the turbine speed to a minimum.2. Shut down the turbine by striking the top of the trip lever by hand.3. Observe the action of the trip valve and linkage.4. Close the main steam isolation valve.NOTEIsolation valves, located in the turbine inlet steam piping,must be closed after the trip valve has closed. Do not usethe trip valve as a long-term shut-off valve.5. If non-condensing turbine, close the exhaust valve and open turbine casing drains.6. If condensing turbine, shut down the condensing equipment, open the turbine casing drains and close the sealing steam shut-off valve.CAUTIONDo not apply sealing steam to the packing cases whilethe turbine rotor is idle. This condition will causeuneven heating of the turbine rotor and casing whichmay result in a distorted casing, bowed rotor shaft orother related problems.7. Allow the rotor to come to a complete stop and cool down for approximately 2 hours before turning off the cooling water or stopping auxiliary oil pump, if supplied.8. If the turbine is to be taken out of service for an extended period, follow the storage instructions in Chapter 1.OPERATION OF EMERGENCY AND STANDBY TURBINESEmergency and standby turbines do not require a warm-up period before applying the load and may be rapidly placed into service. However, it is important that turbines used for emergency and standby services have drain li nes open and isolating valves closed whenthe turbine is idle. Turbines not used for extended periods should be inspected and operated occasionally to verify good working condition.Where impractical to operate the turbine, the rotor should be turned over by hand to introduce oil to the journal bearings (oil ring lubricated turbines). If an auxiliary oil pump is furnished (pressure lubricated turbines), oil can be supplied to the bearings by operatingthe pump. To prevent corrosion, introduce dry, heated air into the casing during shutdown periods.CAUTIONSteam should not be admitted to the turbine casing bypartially opening the main steam isolation valve whilethe rotor is stationary. This condition will causeuneven heating of the turbine rotor and casing, andmay result in a distorted casing, bowed rotor shaft orother related problems.。