Introduction To The Composition And Working Principle Of Diaphragm Valve

Lined Diaphragm Valve uses a corrosion-resistant lined valve body and a corrosion-resistant diaphragm to replace the valve core assembly, and uses the movement of the diaphragm to adjust. The valve body material of the diaphragm valve is cast iron, cast steel, or cast stainless steel, and is lined with various corrosion-resistant or wear-resistant materials, diaphragm materials rubber and polytetrafluoroethylene. The lined diaphragm has strong corrosion resistance and is suitable for regulating strong corrosive media such as strong acids and strong alkalis. The diaphragm valve has a simple structure, small fluid resistance, and a larger flow capacity than other types of valves of the same specification; it has no leakage and can be used for regulating high-viscosity and suspended particle media. The diaphragm isolates the medium from the upper cavity of the valve stem, so there is no packing and the medium will not leak out. However, due to the limitations of the diaphragm and lining materials, the pressure resistance and temperature resistance are poor, and it is generally only suitable for a nominal pressure of 1.6MPa and below 150℃. The flow characteristics of the diaphragm valve are close to the fast opening characteristics, which are approximately linear before 60% of the stroke, and the flow changes little after 60%. Pneumatic diaphragm valves can also be equipped with feedback signals, limiters and positioners to meet the needs of automatic control, program control or flow regulation. The feedback signal of the pneumatic diaphragm valve adopts contactless sensing technology. This product uses a film-type propulsion cylinder to replace the piston cylinder, eliminating the disadvantage that the piston ring is easily damaged, causing leakage and resulting in the inability to push the valve to open and close. When the air source fails, the hand wheel can still be operated to open and close the valve.