The working principle and composition of diaphragm valve.

The diaphragm valve replaces the valve core assembly with the body of the corrosion resistant lining and the corrosion resistant diaphragm, which USES the movement of the diaphragm to regulate. The diaphragm valve body material is cast iron, cast steel, or cast stainless steel, and lined with various corrosion-resistant or wear-resistant materials, diaphragm material rubber and ptfe. The lining diaphragm has strong corrosion resistance and is suitable for the regulation of strong corrosive medium such as strong acid and strong alkali. The diaphragm valve has simple structure, small fluid resistance, and large flow capacity compared with other types of valves. No leakage, can be used for high viscosity and the regulation of suspended particle media. The diaphragm isolates the medium from the stem, so there is no packing medium. However, as a result of the limitation of the diaphragm and lining material, pressure resistance, low temperature resistance, generally applies only to 1.6 MPa nominal pressure and under 150 ℃. The flow characteristics of the diaphragm valve are close to that of the quick-opening feature, which is approximately linear before 60% of the trip, and the flow rate after 60% is not significant. The pneumatic diaphragm valves can be equipped with feedback signals, limiters and locators to meet the needs of automatic control, program control or regulation flow. The feedback signal of the pneumatic diaphragm valve adopts the non-contact sensing technology. The product adopts membrane propulsion cylinder instead of piston cylinder, which eliminates the damage of piston ring and causes leakage, which can not promote the valve opening and closing. When the air source fails, the valve can be opened and closed.