I. Overview 

 300X-type slow closing check valve; valve from the main valve, check valve, needle valve, ball valve, micro filter and pressure gauge type hydraulic control valve to take over the system. Use of hydraulic automatic operation, can make the best main valve opening and closing speed. Chung hit the water to prevent water production, in order to achieve the effect of slow closing muffler. When the valve from the inlet water, the water through the micro-filter, needle valve, check valve into the main valve control room, and then through the drainage valve to the downstream. Because the needle valve opening is less than the opening, the main valve control room of the drainage rate faster than water, so the control room pressure is reduced, the role of the bottom of the main valve disk to open the main valve inlet pressure to the downstream water supply. When the pipe to stop water supply, if the downstream water began to return part of the water by the ball back into the main control room, the one-way valve effect, water can not back out from the main control room, causing the gradual step-up the main control room, slowly turn off the main The products use hydraulic valve self-control, no other devices and energy, maintenance is simple, open, and slowly closed steady. The valves are widely used in high-rise buildings, living quarters and other water supply system and urban water supply project. The main valve part material as follows: 

 Part Name Material 
 Body, bonnet cast iron, cast steel, stainless steel 
 Bronze seat, stainless steel 
 Valve carbon steel, stainless steel + nitrile rubber 
 Stem aluminum bronze, chrome stainless steel 
 Nitrile rubber diaphragm 
 Diaphragm plate carbon steel, stainless steel 
 Stainless steel spring 


 Second, the main dimensions: 

 Nominal diameter size (mm) 
 DN (am) L A1 A H1 HF 
 20 150 200,282,106,172,116 
 25 160 200,282,106,172,116 
 32 180 200,282,106,172,116 
 40 200 210,320,137,225,168 
 50 203 210,320,137,225,168 
 65 216 215,330,145,270,180 
 80 241 220,330,178,289,210 
 100 270 230,410,232,375,284 
 125 300 245,420,286,420,310 
 150 330 260,420,318,450,370 
 200 400 280,430,413,722,463 
 250 480 300,450,502,769,525 
 300 550 320,460,600,906,625 
 3,506,223,404,706,381,480 7