bids are invited for custom bid for services - fabrication of items 1st stage cylinder piston piston rings for gas compressor unite at gcp4 gandhar ankleshwar asset ongc ltd - cylinder ring rider (1st stage) , valve plate (1st stage) , wafer spring/ plate (1st stage) , guide bush (1st stage) , unloader valve cover (1st stage) , closing spring of suction valve (1st stage) , closing spring of discharge valve (1st stage) , valve plate (2nd stage) , wafer spring/ plate (2nd stage) , guide bush (2nd stage) , unloader valve cover (2nd stage) , valve plate (suction)(3rd stage) , wafer spring/ plate (suction) (3rd stage) , guide bush (suction) (3rd stage) , guide/ ring , spring loader/ unloader valve , circlip / retainer ring , pl. spanner (hammer) (102 mm)