网络优化资料：

Check valve performance.

5.1 When producing a valve of a certain specification in batches, an authoritative organization should be entrusted to test the following performance:

②The opening and closing force of the valve under working pressure conditions;

②Under working pressure conditions, the valve can be closed tightly and the number of continuous opening and closing times can be guaranteed;

c Test the flow resistance coefficient of the valve in the state of water delivery in the pipeline.

5.2 The valve shall undergo the following inspections before leaving the factory:

②When the valve is in the open state, the valve body should bear the internal pressure twice of the valve working pressure;

When the B valve is in the closed state, both sides bear 1.1 times the working pressure of the valve, and there is no leakage of the diaphragm solenoid valve; however, the leakage value of the metal sealing butterfly valve is not greater than the relevant requirements.

Anti-corrosion inside and outside the valve.

6.1 The inside and outside of the valve body, including the inside and outside of the variable speed transmission box, should be shot blasted to remove the sand and rust, and the solenoid valve three-way electrostatic spraying powder-like non-toxic epoxy resin should be sprayed, and the thickness should not exceed 0.3mm. When it is difficult for special valves to electrostatically spray non-toxic epoxy resin, similar non-toxic epoxy paint should also be brushed and sprayed.

6.2 All parts of the valve body and the valve plate require comprehensive anti-corrosion. On the one hand, it is immersed in water, which will not cause electrochemical corrosion between the two metals. On the other hand, the surface is smooth, which reduces the water resistance.

6.3 The anti-corrosion and sanitary requirements of epoxy or paint in the valve should have an inspection report from the corresponding authority. The physical properties of chemicals must also meet relevant requirements.