When a valve is manufactured in a certain specification, an authoritative institution should be entrusted to perform the following performance tests:
① The opening and closing torque of the valve under working pressure;
②Under the condition of working pressure, it can ensure the continuous opening and closing times of the valve to be closed tightly;
③Detection of the flow resistance coefficient of the valve under the condition of pipeline water delivery.
The following tests should be carried out before the valve leaves the factory:
② When the valve is closed, both sides are subjected to 1.1 times the valve pressure value without leakage; however, the leakage value of the metal-sealed butterfly valve is not greater than the relevant requirements.