Butterfly valve diameter 100 mm and larger using in vacuum system shall made from
PVC compounds conformed to ASTM D1784. Valve shall be fully lug style with double
eccentric disc, corrosion resistant steel shaft, PTFE seal, and pressure rating not less
than 150 psi at 23C.
Lever-operated valves shall be used for sizes up to 150 mm in diameter. Hand Wheel
gear-operated valves shall be used for sizes larger than 150 mm in diameter. Position
indicators shall be provided to indicate valve disc position.