6.6　Control Oil System

6.6.1　This section is applicable to the installation of parts of regulation and protection system，such as HP fire-resistant oil system pipes，oil supply and regeneration unit and accumulator；and it can be referenced when turbine oil is used as HP control medium.

6.6.2　For installation of oil pipes of LP protecting system of regulation and protection system，refer to 6.7.

6.6.3　The installation of HP fire-resistant oil pipes shall also comply with the following provisions，in addition to relevant provision sin 6.1:

1　Provisions for installation of HP fire-resistant oil pipes:

1）The pipes，pipe fittings and oil tanks of HP fire-resistant oil system shall be made of stainless steel.

2）Weld neck flanges shall be used for HP control oil pipes.

3）The sealing surfaces of oil pipe flanges shall be flat and smooth，in homogeneous contact and must be free of through groove.

4）When teflon tape is used as sealing materials for threaded connectors，the first two thread at threaded ends shall not be wrapped.

5）For fire-resistant oil system the sealing ring should be fluorine rubber.

6）Pipes may be purged with clean compressed air before installation，and the inner wall of pipes can be wiped with silk fabric dipped with anhydrous alcohol or acetone.Clean pipes not to be installed for a time being shall be sealed up，to prevent dust from entering the pipe.Chloride solvent must not be used for cleaning of fire-resistant oil pipes and parts.

7）Pipe bends should have large curvature radius，and right angle connector should not be used.

8）Bent places shall be smooth，and free of wrinkle，torsion or flatten.

9）In bending，the bend radius shall be equal and the minimum straight length at both ends of the bend shall comply with manufacturer requirements.

10）Pipes should be cut with a saw，and pipe cutter，grinding wheel pipe cutter or flame cutting must not be used；after pipe cutting the ends shall be clean and smooth，and must not have burr or curled edge.

11）Argon arc welding shall be used for stainless steel pipes.

2　Arrangement of pipes shall comply with the following provisions:

1）Pipes shall incline towards the oil tank，and the inclination shall comply with manufacturer requirements.

2）Connectors shall not be subject to load.

3）Pipe expansion compensation shall comply with relevant provisions in 6.1.4.

4）Pipes arrangement shall facilitate maintenance，their routing shall be parallel or vertical to turbine centerline，and intersection shall be avoided.

5）Reinforced Tees shall be used at intersection of pipes.

3　HP fire-resistant oil pipes shall be provided with heavy load pipe clamps supplied by manufacturer，at the contact of pipe clamps and pipes，elastic materials resisting to a temperature of 100℃should be used，pipe clamps shall be provided upstream and downstream a pipe bending，and the spacing of pipe clamps shall comply with manufacturer requirements.

4　Before oil circulation in the fire-resistant oil system，the orifice plugs，unloading valve body，springs and standby fluorine rubber sealing rings removed from assemblies shall be cleaned and marked，and be sealed in clean plastic bags，for fitting back after the oil is up to specification.

6.6.4　Installation of oil supply unit shall comply with the following provisions:

1　After opening case，oil tanks，oil pump，oil filter，magnetic filter，overflow valve，accumulator，selfcirculation cooling system，fire-resistant oil regeneration and filtering system，oil tank heater of oil supply unit shall be checked and comply with requirements on drawings，and shall be in a sound condition without damage.

2　After opening case，protection shall be taken for the oil supply unit，to prevent contamination of its parts during installation.

3　The oil outlet of oil supply unit should face the turbine direction，be kept away from high temperature and HP steam pipes by at least 1.5 m，and there shall be no high temperature steam pipes and valve above the unit.

6.6.5　Installation of accumulator assembly shall comply with the following provisions:

1　The accumulator shall be free of leakage or damage after pressure test，and the parts shall be cleaned before assembling.

2　The accumulator assembly should be installed on the side of turbine on operation floor.

3　The installation location of HP accumulator shall be as close to the actuator as possible.

6.6.6　Works on HP fire-resistant oil system after oil filling shall observe the following provisions:

1　The environment of work area shall be well ventilated and be free of dust.

2　Operators shall wear goggles，to prevent burning eyes by spilled liquid.

3　After completion of work，working personnel shall wash and clean skin having contacted fireresistant oil in time.

4　The fire-resistant oil drained during work shall be stored properly and disposed of together.