2003-2004 Overhaul Report.pdf

MAINTAIN TURBINE-GENERATOR #4 APPENDIX 3

EIELSON AFB, ALASKA 2003/2004 Overhaul Report

FTQW 07-1054

Appendix 3

2003/2004

OVERHAUL

REPORT

FINAL INSPECTION REPORT

EIELSON AFB

EIELSON AFB, ALASKA

WORTHINGTON #4 TURBINE GENERATOR

SERIAL NUMBER #27127

Per Contract F65503-02-C-0015, Section 15699 3.04

AGREEMENT NO. F65503-02-C-0015

TMI JOB NO. 1168

INSPECTION STARTED: 01-April-03

INSPECTION COMPLETED: 31-March-04 wilsondm Rectangle

TABLE OF CONTENTS

PARTS AND ACCESSORIES

VIBRATION ANALYSIS

TURBINE TEAR DOWN

TURBINE CASING AND BOLTING

DIAPHRAGMS

NON-RETURN VALVE

EXTRACTION ISOLATION VALVE

STRAINER

ATMOSPHERIC RELIEF VALVE

V-I CONTROL VALVES

V-II CONTROL VALVES

CAM SHAFT AND VALVE LINKAGE

LABYRINTH PACKING

MAIN SHAFT COUPLING

ROTOR BEARINGS

TURBINE ROTOR

FIRST STAGE NOZZLE BLOCK

OIL DEFLECTORS

SPEED PICK-UPS

EMERGENCY GOVERNOR

TRIP AND THROTTLE VALVE

LINKAGES AND TRIPPING MECHANISMS

TURNING GEAR

CONDENSATE PUMPS

MAIN OIL PUMPS

STEAM DRIVEN AUXILIARY OIL PUMP

MOTOR BEARINGS

MAIN OIL SYSTEM COOLERS

MAIN CONDENSER

AIR EJECTOR SYSTEM

STEAM SEAL CONTROL SYSTEM

STATOR

FIELD

EXCITER

ELECTRIC LEADS

GENERATOR AIR COOLER

VOLTAGE REGULATOR

AUTO-SYNCHRONIZATION RELAY

VIBRATION MONITORING SYSTEM

NON-DESTRUCT TESTING

BALANCE TURBINE ROTOR AND GENERATOR

TURBINE REASSEMBLE

REPLACE INSULATION & LAGGING

STARTUP

OBSERVATIONS & RECOMMENDATIONS

June 30, 2004

Attn: Mr. Mike Lelevier C.O.

Eielson AFB

354 CONS/LGCC

3112 Broadway Ave. Unit 5B Eielson AFB, Alaska 99702-1887

Re: Contract F65503-02-C-0015 Subject: #4 Turbine Generator, Serial No. 27127

Dear Mr. Lelevier:

This documentation covers work performed under the supervision of Turbo Mechanical Inc. on your Worthington #4 Turbine Generator Serial No. 27127, in accordance with standard procedures for inspection of turbine generators.

SUMMARY

On October 22, 2002, Turbo Mechanical Inc., was given the Notice to Proceed, from the Contracting Office at 354 Cons/LGCC, Eielson AFB, Eielson AFB, AK to perform an overhaul on the Worthington #4 Turbine Generator Serial No. 27127.

In general terms, the machine was found to be in fair condition considering the age and design of the unit.

The only surprise encountered was the extreme erosion present on three of the turbine wheels. Our findings and repairs are outlined in the body of this report.

NOTE: All clearances, dimensions, and diagrams are at the end of this report

Sincerely, William R. Hamaker President

Section 15699, 3.04, A. PARTS AND ACCESSORIES

Our preliminary inspection revealed the following:

All parts and accessories were placed in temporary storage areas as needed and were arranged as orderly as possible throughout the turbine area.

Section 15699, 3.04, B. VIBRATION ANALYSIS

1. A full spectrum vibration analysis was performed on the machine prior to shut down at varying load and extraction rates. See attached report by Tern Technologies in Chapter B.

2. The vibration data collected by Bently Nevada Corporation at startup was of the orbital alignment method. See Bently Nevada report in Chapter C.

Section 15699, 3.04, C. TURBINE TEAR DOWN

1. All of the turbine lagging was removed and placed in a temporary storage area.

2. All necessary insulation material was removed and stored. It was noted during the removal process that the insulating material was of the block and canvas cover type material.

3. The heat retention material will be replaced with new removable blanket type material in accordance with contract requirements.

4. The turbine was completely disassembled and all components inspected in accordance with contract requirements.

Section 15699, 3.04, D. & E. TURBINE CASING AND BOLTING

1. The turbine casing bolts were removed with some difficulty.

2. The upper casing was removed to facilitate a more thorough examination of the unit's internals.

3. The turbine hood was turned over to facilitate the removal and inspection of the upper diaphragms. Minor indication of cracks were found throughout the unit.

4. The lower casing was inspected and found to be in good condition with some water washing present on the last two stages.

5. The diaphragm fits were examined and the steam seal surfaces are in excellent condition.

6. The internal struts and supports appeared to be in good serviceable condition with no indication of cracks.

7. All of the diaphragm retaining bolts should be replaced. All of the labyrinth packing retaining bolts should be replaced.

8. The high and low pressure packing boxes were inspected and found to be in good working order.

9. The casing was cleaned mechanically, NDE inspected using the wet fluorescent magnetic particle and black light method with no indications being found.

The following is a description of activities performed to return the unit to service:

1. New diaphragm retention bolts and stops were fabricated and installed. The nozzle bolting and caulking was replaced with new parts. All of the diaphragms were weld repaired per the NDE report and returned to service.

2. All main turbine case dowels were replaced with new parts obtained from our vendors.

D. & E. TURBINE CASING AND BOLTING (continued)

DIAPHRAGMS

1. All of the diaphragms were removed and inspected.

2. There were indications of excessive wear and erosion present in the diaphragm packing cells of numbers 2, 3, and 4.

3. The horizontal joint seal areas were all inspected and found to be in serviceable condition.

The following is a description of activities performed to return the unit to service:

1. We repaired the diaphragms using a mechanical insert and pinning to replace the damaged cells on numbers 2, 3, and 4 diaphragms. This was done as a cost saving effort and to eliminate long lead times on fabricating complete new assemblies.

2. All of the packing locking devices were replaced and all broken retention screws replaced.

Section 15699, 3.04, F. NON-RETURN VALVE

1. The non-return valve could not be isolated during this outage do to excessive steam leakage past the main isolation block valve.

2. The actuator mechanism was disassembled and inspected and found to be in poor condition.

3. The hydraulic side of the valve was disassembled and inspected and severe galling was present on the piston and the cylinder bore. The seal rings and scrapper assembly were severely worn.

1. At the first opportunity when the plant goes down cold, replace the isolation valve and inspect the non-return valve.

2. We repaired the operating mechanism by building a new piston assembly and honing the cylinder bore. New Viton O-Rings and seals were installed.

Section 15699, 3.04, G. EXTRACTION ISOLATION VALVE

1. The extraction isolation valve could not be isolated during this outage. At the first opportunity when the plant goes down cold, replace the isolation valve.

1. At the first opportunity when the plant goes down cold, replace the isolation valve.

Section 15699, 3.04, H. STEAM LINE STRAINER

1. The strainer was disassembled and inspected and found to be in good

2. The strainer basket was dust-blasted, using 220 aluminum oxide and NDE inspected using the wet fluorescent magnetic particle and black light method with no indications being found.

1. None taken

Section 15699, 3.04, I. ATMOSPHERIC RELIEF VALVE

1. The atmospheric valve was disassembled and inspected and found to be in fair condition.

2. The valve disc will require lapping.

3. NDE was performed using the dye penetrant method and black light with no indications being found.

1. We lapped the disc to obtain correct contact and reestablished a 100% seal surface using the Prusian Blue method for verification. The valve pivot shaft and bushings were in good serviceable condition.

Section 15699, 3.04, J (a). V-I CONTROL VALVES

1. The V-I control valves were removed, cleaned, and the valve stems NDE-inspected, using the magnetic particle and black light method.

2. The number five valve was frozen in place and had to be extracted. The globe also had spider cracks present.

3. There were severe indications of pitting present. The seats were in generally poor condition with indications of pitting and material loss.

4. Valve numbers 1, 2, 3, 4, 5, 6, and 7 show indications of steam cutting and/or erosion. The number 6 valve body had deep holes present with cracks radiating outward.

5. Valve seats numbers 1, 2, 3, 4, and 5 show indications of steam cutting and/or erosion. These valve seats will require replacement.

6. The lift rods were inspected and found to be in serviceable condition.

7. All of the alignment dowels in the steam chest required replacement.

1. We replaced all five valve seats and re-welded in place.

2. We replaced seven valves and valve stems that were manufactured by our shop.

3. We replace all valve assembly dowels.

4. All of the guide bushings were replaced

Section 15699, 3.04, J (b). V-II CONTROL VALVES

1. The V-II control valves were removed, cleaned, and NDE-inspected, using the magnetic particle and black light method. There were no indications of distress or pitting on the valve seats. The seats were good with no indication of wear or spinning present.

2. Discs number 1 and 2 show indication of steam cutting and/or erosion.

These valves will require replacement as well as two valve stems. All valves and seats will be lapped using lapping blocks.

3. The lift rods were inspected and found to be in good condition. The bushings were replaced.

4. All of the alignment dowels in the steam chest required replacement.

1. We replace two valves and stems with parts manufactured by our shop.

2. We replace all valve assembly dowels.

3. All of the valve seats were lapped until a good contact surface was obtained.

4. All of the valve stem guide bushings were replaced with parts manufactured by our shop.

Section 15699, 3.04, K. CAM SHAFT AND VALVE LINKAGE

1. The cam shaft and valve rack was, generally, in fair condition as the operators have been lubricating the system diligently.

1. Per contract requirements, all the valve gear rack needle bearings and bushings were replaced..

Section 15699, 3.04, L. LABYRINTH PACKING (SEALS)

1. The labyrinth packing was found in poor condition with several broken springs present.

1. All labyrinth packing and springs were replaced with parts manufactured by our vendor.

Section 15699, 3.04, M. MAIN SHAFT COUPLING

1. The Main Shaft Coupling was found to be in poor condition with severe gear tooth contact wear and brinneling present.

1. The main shaft coupling was replaced with a Kop-flex KD 454 assembly.

We torqued the main flex bolts to 288 ft. pounds.

Section 15699, 3.04, N. ROTOR BEARINGS

1. Per contract requirements, all bearings were rebuilt and a full set of new bearings provided for spares.

1. Four complete new bearing assemblies were manufactured and placed in customer’s stores.

2. The existing turbine rotor bearings and thrust shoes were re-babbitted and installed.

Section 15699, 3.04, O. TURBINE ROTOR ASSEMBLY

1. The turbine rotor was removed from the machine and moved to the dust-blast area where it was dust-blasted, using 220 aluminum oxide.

2. A full NDE inspection was performed using the mag particle and black light method.

3. Three stages (3, 7, 14) buckets will require replacement in accordance with the NDE report.

4. The turbine journals have radial scoring present and should be hard chromed and ground to original diameters.

5. All of the wheel locking rings are loose and moving on the shaft and should be replaced.

6. Wheel numbers 5 & 7 had severe corrosion damage in the root section and could not be repaired.

1. Rows (5, 7, 14) buckets and shroud bands were replaced with parts manufactured by our vendor.

2. Both turbine rotor journals were hard chromed and ground.

3. At reassembly all new locking rings were installed on all stages.

4. The turbine rotor was balanced to the ISO G 2.5 specification.

5. Wheels 5 & 7 were manufactured to replace damaged wheels.

6. A new rotor stand was fabricated per contract requirements and turned over to the plant upon completion of the project.

Section 15699, 3.04, P. FIRST STAGE NOZZLE BLOCK

1. The first stage nozzle was thoroughly cleaned, using 220 aluminum oxide in preparation for NDE procedures.

2. An NDE by the mag particle method was performed and all indications were good with no cracks or erosion pitting present.

1. Replaced all nozzle bolts and caulking.

Section 15699, 3.04, Q. OIL DEFLECTORS

1. The oil deflectors were inspected and found to be in very poor condition with warping and impact damage being present.

2. Some of the oil deflectors had excessive clearance as witnessed by the amount of oil present in the generator and contaminating the exciter.

1. All of the oil deflectors were replaced with parts manufactured at our shop.

Section 15699, 3.04, R. SPEED PICK-UPS

1. The speed pick-ups were removed and inspected and found to be in

1. No remedial action taken.

Section 15699, 3.04, S. EMERGENCY GOVERNOR

1. The emergency governor was disassembled and inspected and found to be in serviceable condition.

1. No action taken.

Section 15699, 3.04, T. TRIP AND THROTTLE VALVE

1. The trip throttle valve was completely disassembled and inspected.

2. The steam side valve internals and valve disks were NDT-inspected using the dye penetrant and black light method. No indications of cracks, distress or fatigue were noted on the spool, pilot, body, or seats.

3. The valve stem had heavy indications of steam erosion and pitting present in the packing area. The mechanical side of the valve was disassembled, cleaned, and reassembled using proper lubricants.

4. The internal pilot valve was found to be in good condition, however, the assembly bolts should be replaced.

1. All trip throttle valve bolting was replaced with parts manufactured at our facility.

2. A new valve stem was manufactured by our facility.

3. New gaskets were installed on all assemblies.

Section 15699, 3.04, U. LINKAGES AND TRIPPING MECHANISMS

1. All the linkages and tripping mechanisms were disassembled and inspected and found to be in serviceable condition.

1. No action taken.

Section 15699, 3.04, V. TURNING GEAR

1. This item eliminated by modification to the contract..

1. Although we were unable to obtain the turning gear for this machine, the

Government can pursue obtaining one through Worthington.

Section 15699, 3.04, W. CONDENSATE PUMPS

1. The condensate pumps were completely disassembled and inspected.

2. All bearings, seals and coupling should be replaced.

3. The packing sleeves were severely worn .

1. Replaced shaft sleeves with parts manufactured at our facility.

2. All bearings, seals, and couplings were replaced during this outage.

Section 15699, 3.04, X. MAIN OIL PUMPS

1. The main oil pumps were completely disassembled and inspected.

2. All bearings, seals, and couplings should be replaced during this outage.

3. The pump internals appeared to be in good serviceable condition

1. All bearings, seals, and couplings were replaced during this outage.

Section 15699, 3.04, Y. STEAM DRIVEN AUXILIARY OIL PUMP

1. The oil pump was completely disassembled and inspected.

2. The steam side was dust-blasted and NDE performed using the magnetic particle and black light method with no indications being present.

3. The bearing lock nut was damaged and should be replaced.

4. The carbon packing was in very poor condition and should be replaced.

5. The labyrinth seal has excessive clearance and should be replaced.

1. The damaged lock-nut was repaired.

2. All carbon packing was replaced.

3. A new labyrinth seal was manufactured and installed.

4. Installed two new bearings (P/N 7307WN SU 6K Lot # 26715).

Section 15699, 3.04, Z. MOTOR BEARINGS

1. The condensate and oil pump motors were removed and completely disassembled.

2. The units were cleaned and megger-tested satisfactorily.

3. New bearings were installed in all units and returned to service.

4. The main oil pump motors have been over-serviced and this procedure should be modified to eliminate over-lubrication.

Section 15699, 3.04, AA. MAIN OIL SYSTEM

1. The main oil coolers were isolated to facilitate a complete and thorough inspection.

2. The oil cooler bundles and heads were severely eroded and weakened to the point that it is questionable whether they could be reassembled without leaking.

1. We replaced both oil coolers with new units.

2. We provided a spare oil cooler unit to facilitate a quick change out if a problem arises.

Section 15699, 3.04, BB. MAIN CONDENSER

1. The main condenser was completely stripped of all tubes and the tube sheets and support plates cleaned of contaminates.

1. New tubes were installed and rolled to specifications.

2. The water boxes were resealed and pressure tested satisfactorily

Section 15699, 3.04, CC. AIR EJECTOR SYSTEM

1. The inter and after condenser was completely stripped of all tubes, and the tube sheets and support plates.

2. After several discussions, with the original equipment manufacturer, it was discovered that the nozzles and inter-after condensers were improperly sized for this application.

1. Replaced both the inter and after condenser assemblies as a unit.

2. Both drain traps were replaced.

3. The two primary and two secondary nozzles were replaced with parts obtained from the original equipment manufacturer.

Section 15699, 3.04, DD. STEAM SEAL CONTROL SYSTEM

1. The system will be modified per specifications.

1. The steam seal control system (Including Steam Seal Control Valves and

Steam Seal Condenser) were modified to specifications in accordance with Worthington Figure 20 Drawing LE-11870.

2. The steam seal condenser and piping were replaced in accordance with specifications.

Section 15699, 3.04, EE. STATOR

1. The stator was found to be in excellent electrical condition. See attached report. See the Generator Test and Inspection report Chapter D.

2. Several locations within the core iron had delimitated.

3. Several mechanical rubs were in evidence and should be repaired.

1. We repaired the delaminated core iron using epoxy.

2. We repaired mechanical rubs in core iron and re-varnished.

3. We applied varnish to end turn cracking.

4. New connecting bolts were installed on the main leads.

5. New removable high voltage bushing boots were fabricated and installed.

Section 15699, 3.04, FF. FIELD

1. The field was completely disassembled and cleaned and all electrical tests performed in accordance with contract requirements. See attached report.

See the Generator Test and Inspection report Chapter D.

2. The Textolite internal blocking under the retaining rings had begun cracking.

This was not a problem at this time as the entire assembly is contained in grooves which prevent movement.

3. The journal had radial scoring present and should be hard chromed and ground to original specifications.

1. The journal was hard chromed and ground to original dimensions.

2. The field was balanced as a unit after all work was completed to the ISO

G 2.5 specification.

3. A new rotor stand was fabricated per contract requirements and turned over to the plant upon completion of the project.

Section 15699, 3.04, GG. EXCITER

1. The exciter was completely disassembled and cleaned and all electrical tests performed in accordance with contract requirements.

2. The dog house was found to be in extremely poor condition with plugged filters and vents.

1. The exciter was steam-cleaned, baked, and re-varnished.

2. All fuses and diodes that were questionable were replaced. All others were placed in customer's spares.

3. The field surge protector was found to be in-operative and was replaced.

4. The exciter dog house was cleaned using compressed air, vacuum, and rags.

Section 15699, 3.04, HH. ELECTRIC LEADS

1. The leads were inspected in accordance with contract specifications with no problems found.

1. No action taken

Section 15699, 3.04, II. GENERATOR AIR COOLER

1. The water side of the tubes was in very poor contaminated condition.

1. The generator air coolers were cleaned on the water side and placed back in service.

Section 15699, 3.04, JJ. VOLTAGE REGULATOR

1. The voltage regulator will be replaced according to contract requirements.

1. The voltage regulator was installed.

Section 15699, 3.04, KK. AUTO-SYNCHRONIZATION RELAY

1. The auto-synchronization will be replaced according to contract requirements.

1. The auto-synchronization equipment was installed

Section 15699, 3.04, LL. VIBRATION MONITORING SYSTEM

1. The vibration monitoring system will be replaced according to contract requirements.

1. The vibration monitoring equipment was installed.

Section 15699, 3.04, MM. NON-DESTRUCT TESTING

1. All testing was accomplished in accordance with contract specifications and the report from QIT is attached.

1. All testing was accomplished in accordance with contract specifications.

2. Action was taken to address all indications found during NDE operations.

Section 15699, 3.04, QQ. BALANCE TURBINE ROTOR AND GENERATOR

1. The turbine and generator rotor will require total balancing after all work is performed.

1. The turbine and generator rotor were balanced to the ISO G 2.5 specification.

Section 15699, 3.04, RR. TURBINE REASSEMBLE

1. All non conforming parts and pieces that were found during the inspection were addressed as necessary.

1. All sub components and assemblies were repaired or replaced in accordance with proper engineering standards. The turbine and generator and all auxiliaries were re\assembled and tested satisfactorily.

Section 15699, 3.04, SS. REPLACE INSULATION & LAGGING

1. All insulation and lagging were removed to facilitate a thorough inspection.

1., All insulation material was replaced with removable blanket type heat retention material.

2. The metal lagging was reinstalled after startup.

Section 15699, 3.04, TT. STARTUP

1. During startup we discovered several oil leaks and minor rubs on the generator ail seals.

2. The shaft surge protector on the generator shorted out.

3. A full governor alignment procedure was performed and all control parameters verified.

4. Several steam leaks were found in numerous flange and fitting locations.

1. The shaft surge protector was replaced.

2. All steam and oil leaks were repaired.

3. A final acceptance list was made and all objectionable details were addressed.

4. Startup was performed by plant personnel in accordance with their operating procedures.

5. We modified the plant operating procedure for this initial startup as follows:

a. We brought the machine up to 200 RPM, for 45 minutes, and tested the mechanical trip to insure that the TT valve was functioning properly.

b. The machine was returned to 200 RPM for another ½ hour and then the Woodward Governor was given control to the 500 idle speed set point . The Woodward was placed on automatic and the machine ran up to 3600 RPM and held for 15 minutes.

c. Some difficulty was encountered with the field excitation surge protection device. The unit was replaced and the turbine was put on-line.

OBSERVATIONS & RECOMMENDATIONS

The job was completed according to the requirements of the contract and there is nothing that needs to be entered in this section.

INDEX

A

AIR EJECTOR SYSTEM · 33

ATMOSPHERIC RELIEF VALVE · 12

AUTO-SYNCHRONIZATION RELAY · 41

B

BALANCE TURBINE ROTOR AND GENERATOR · 44

C

CAM SHAFT AND VALVE LINKAGE · 15

CONDENSATE PUMPS · 27

D

DIAPHRAGMS · 8

E

ELECTRIC LEADS · 38

EMERGENCY GOVERNOR · 23

EXCITER · 37

EXTRACTION ISOLATION VALVE · 10

F

FIELD · 36

FIRST STAGE NOZZLE BLOCK · 20

G

GENERATOR AIR COOLER · 39

L

LABYRINTH PACKING · 16

LINKAGES AND TRIPPING MECHANISMS · 25

M

MAIN CONDENSER · 32

MAIN OIL PUMPS · 28

MAIN OIL SYSTEM · 31

MAIN SHAFT COUPLING · 17

MOTOR BEARINGS · 30

N

NON-DESTRUCT TESTING · 43

NON-RETURN VALVE · 9

O

OBSERVATIONS & RECOMMENDATIONS · 48

OIL DEFLECTORS · 21

P

PARTS AND ACCESSORIES · 4

R

REPLACE INSULATION & LAGGING · 46

ROTOR BEARINGS · 18

S

SPEED PICK-UPS · 22

STARTUP · 47

STATOR · 35

STEAM DRIVEN AUXILIARY OIL PUMP · 29

STEAM SEAL CONTROL SYSTEM · 34

STRAINER · 11

T

TRIP AND THROTTLE VALVE · 24

TURBINE CASING AND BOLTING · 7

TURBINE REASSEMBLE · 45

TURBINE ROTOR · 19

TURBINE TEAR DOWN · 6

TURNING GEAR · 26

V

V-I CONTROL VALVES · 13

VIBRATION ANALYSIS · 5

VIBRATION MONITORING SYSTEM · 42

V-II CONTROL VALVES · 14

VOLTAGE REGULATOR · 40

WXYZ

(No entries)

CONTROL VALVE

CONTROL VALVE DAMAGE

VALVE SEAT DAMAGE

BLUE PRINTING VALVE STEMS

VALVE CONDITION

VALVE SEAT CONDITION

AIR EJECTOR

AIR EJECTOR DAMAGE

AIR EJECTOR DAMAGE

DIAPHRAGM

DIAPHRAGM DAMAGE

DIAPHRAGM DAMAGE

DIAPHRAGM INDICATIONS

DIAPHRAGM INDICATIONS

NOZZLE BOLT

ROTOR

ROTOR 14TH STAGE DAMAGE

14TH STAGE EROSION

WHEEL EROSION

BUCKET EROSION

WHEEL EROSION

CONTAMINATION

MISSING LOCK RING

THRUST RUNNERS

THRUST RUNNERS

ROTOR AFTER BLASTING

FIELD

FIELD

FIELD - EXCITER END

CASE

CASE CONDITION

CASE CONDITION

CONDENSATE PUMP

CONDENSATE PUMP SEAL

BEARINGS

THRUST ASSEMBLY

#2 JOURNAL BEARING

CONDENSER

CONDENSER CONDITION

PULLING CONDENSER TUBES

T. T. VALVE

T. T. VALVE STEM

STATOR

GENERATOR AIR COOLER

GENERATOR AIR COOLER CLEANING

GENERATOR AIR BOX CONTAMINATION

GENERATOR AIR COOLER WATER SIDE CONTAMINATION

GENERATOR AIR COOLER WATER SIDE CONTAMINATION

OIL COOLER