bids are invited for procurement of wafer type dual check valves, 1 wafer type dual plate check valves size 350 mm working pressure 150 psig 2 wafer type dual plate check valves size 250 mm working pressure 150 psig 3 wafer type dual plate check valves size 200 mm working pressure 150 psig 4 wafer type dual plate check valves size 150 mm working pressure 150 psig 5 wafer type dual plate check valves size 100 mm working pressure 150 psig 6 wafer type dual plate check valves size 80 mm working pressure 150 psig 7 wafer type dual plate check valves size 50 mm working pressure 150 psig total quantity : 222