Turbo Gen Services

Seal oil systemDate: 30 March 2015

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CONTENTS

• Function

• Line diagram

• P&ID

• Alarm settings

• Alarm analysis

• Procedure - Filling seal oil system

• Procedure – Commissioning Vacuum pump

• Seal oil system check sheets

• Blanking procedure

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INTRODUCTION

FUNCTION

•Seals both ends of the generator shaft against Hydrogen loss, as the generator casing is filled with hydrogen gas and at the same time prevents the ingress of air directly into the generator.

OIL QUALITY:

•Oil spec should be 15/12 because of trip block and control oil feed to governors and emergency stop valves.

•Maximum allowable content of water is 200 ppm.

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CONSTRUCTION

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PIPING & INSTRUMENTATION DRAWING

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AIR-OIL CIRCUIT

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DEGASSY CIRCUIT

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GASSY CIRCUIT

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ALARM – HYDROGEN/SEAL OIL DIFF PRESS

Settings:

•High Alarm: 95 kPa

•Low Alarm: 30 kPa

When diff press is 25 kPa

•Standby pump cuts in after 3 seconds

•DC pump cuts in after 5 more seconds

•Trip with 20 seconds delay

•When on barring the barring gear trips after 20 seconds

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ALARMS - MOT

Settings

•Low Level Alarm: equal or less than 960mm from the top of MOT.

•Trip: equal or less than 1050mm from the top, immediate trip.

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ALARM ANALYSIS

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Problem Cause RemedySeal oil filter diff pressure high Fouled filter. Change over to a standby filter and

clean that filter that was in use.

H2/seal oil diff pressure high. Standby pump started.Hydrogen system leak.Hydrogen discharge valve opened

Use one pump.Search for a leak.Close discharge valve.

H2/seal oil diff pressure low. Seal oil filter diff pressure high. Failure of supply seal oil pump.

Clean filter.Use standby pump.

No seal oil pressure indication after starting aux seal oil pump.

Pressure signal not received. Pump not turning/ Pump rotation reserved. Check valve installed in a wrong way. Isolating valve closed

Check pressure gauge/pressure transmitter.Check pump’s rotation.Correct the rotation Re-install, check flow direction arrow  Open an isolating valve.

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FILTER CHANGE OVER - PROCEDURE

• ..\February 2015\procedure\Procedure - Seal Oil Filter Replacement.doc

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FILLING THE SEAL OIL SYSTEM

• ..\February 2015\procedure\Procedure - Seal Oil Filling of the system.docx

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CHECKSHEETS

• Seal Oil Pre-barring check.xlsx

• Seal Oil Barring check.xlsx

• Seal Oil check at 3000 rpm.xlsx

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BLANKING PROCEDURE

• ..\January Presentation\Lube Oil System\Procedure for control of blanks and spades.doc

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Thank You