Ball valve 80 mm diameter and smaller using in vacuum system shall made from PVC
compounds conformed to ASTM D1784, full port, blow-out proof stem, double union
type with socket ends, pressure rating not less than 150 psi at 23C.
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.