BODY – MSS SP-81 requires the valve body (pressure vessel and related structure) to be designed for and hydrostatically pressure tested to 1.5 times the rated working pressure.
– Valve rated pressure – 150 psi
– Body test pressure – 225 psi
GATE – MSS SP-81 requires the gate to be designed for and hydrostatically pressure tested to 1.1 times the rated working pressure.
– Valve rated pressure – 150 psi
– Gate test pressure – 165 psi
SEAT – MSS SP-81 has an allowable leakage rate (for metal to metal seated valves) of 40 cc per inch of diameter, per minute at 40 psi pressure. On a 12” valve this would be equal to 40 times 12, or 480 cc per minute at 40 psi.
– Maximum allowable leakage of 0.6 GPM when tested with water at 40 psi applied in the normal flow direction.
– No visible leakage when tested with water at 40 psi (for soft seated valves only).
Face to Face – MSS SP-81 has specified face-to-face dimensions and tolerances for each valve size to assure ease of installation for the consumer, regardless of the valve manufacturer.