GE 7FA.05 - Inlet Bleed Heat Systems; Piping Insulation; Manual Stop Valve; Control Valve

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GEK 116862 Inspection and Maintenance Instructions for 7FA.05 Gas Only and Dual Fuel Gas Turbines

XXVI. INLET BLEED HEAT SYSTEMS

A. Piping Insulation

The insulation installed on the inlet bleed heat piping between the turbine base and the inlet duct is

for personnel protection and heat retention. Therefore, the insulation should be inspected to assure

that there is no exposed piping in both operator accessible and non-accessible areas. Valves are to be

insulated as well.

B. Manual Stop Valve

Check for excessive gas leakage at the valve stems and packing leakoff.

C. Control Valve

Check for excessive gas leakage at the valve stems and packing leakoff.

If it is suspected that the valve leaks, check the seating surfaces for damage or foreign material.

Contact between the valve and seat must be checked with the stem in place. Check the rod seals and

wipers of the hydraulic cylinders for leakage and replace them if worn.

Check the trip relay for cleanliness and freedom of operation. A small amount of dirt can cause the

relay to stick. Disassemble and clean if necessary.

If the movable core on the LVDT appears to be misaligned with the stationary coil and is rubbing the

coil, realign it.

For additional information on the control valve, refer to the Operation and Maintenance Manual

under the Inlet System.

D. Pressure Transmitters

Check that the transmitters are calibrated within the limits described in the Control Specification.

E. Inlet Bleed Heat Manifold

Inspect the drilled holes (orifices) in the manifold tubes for any obstructions. Clogged holes will

result in unacceptable temperature variations across the compressor inlet. Clean if necessary.

XXVII. INSTRUMENTATION

A. Pressure/Temperature Transmitters

WARNING

EXPLOSIONS COULD RESULT IN DEATH OR SERIOUS INJURY

DO NOT REMOVE THE TRANSMITTER COVERS IN AN EXPLOSIVE

ATMOSPHERE. WHEN THE CIRCUIT IS ALIVE, HIGH VOLTAGE

THAT MAY BE PRESENT ON LEADS COULD CAUSE ELECTRICAL

SHOCK.

AVOID CONTACT WITH LEADS AND TERMINALS