300X relief valve closed device equipment Shanghai 300X relief valve closed

Slow closing check valve works: When the valve from the inlet end of the water supply, the water through a microfilter, needle valve, check valve into the main valve control room, and then through the drainage valve downstream. Because the needle valve opening degree of opening is less than that of the main valve control room faster than water drainage speed, so the control room pressure is reduced, the role of opening the main valve inlet pressure on the lower end of the main valve disc to the downstream water supply. When the pipe to stop water supply, if the downstream water began to reflux, a part of the water through the valve back into the main control room, the one-way valve action, return water can not flow out from the main control room, causing the main control room gradually boost, slowly close the main valve .