Valve performance testing requirements

1. When valves of a certain specification are manufactured in batches, an official agency should be entrusted to conduct the following performance testing:
① The opening and closing torque of the valve under working pressure;
② Detection of the flow resistance coefficient of the valve under pipeline water transmission conditions.
2. The valve should undergo the following tests before leaving the factory:
① When the valve is open, the valve body should withstand an internal pressure test that is twice the working pressure of the valve;
② When the valve is closed, both sides can withstand 11 times the working pressure of the valve without leakage; however, for metal-sealed butterfly valves, the leakage value is not greater than the relevant requirements.