Introduction to Diaphragm Valves
Diaphragm valves represent a widely utilized type of control valve in industrial applications, commonly employed in liquid, gas, and powder pipeline systems. Their distinctive design confers numerous advantages and application-specific features. Below is an overview of key aspects related to diaphragm valves:
Structural Features:
A diaphragm valve consists of a valve body, valve cover, diaphragm, and actuation mechanism. The valve body is typically fabricated from materials such as cast iron, stainless steel, or plastic, while the valve cover is often constructed from cast iron, steel, or plastic. The diaphragm, positioned centrally, is made from elastic materials, including rubber, polytetrafluoroethylene (PTFE), and nitrile rubber. The actuation mechanism may be manual, pneumatic, or electric, depending on the application requirements.
Working Principle:
The operation of a diaphragm valve relies on the movement of the diaphragm to control fluid flow. When the valve is closed, the diaphragm forms a seal between the valve body and valve cover, effectively preventing fluid passage. Upon opening the valve, the actuation mechanism applies force to the valve cover's stem, causing the diaphragm to lift off the valve body and enabling fluid flow. By adjusting the force exerted by the actuation mechanism, the valve's opening degree can be precisely controlled, thereby regulating the fluid flow rate.
Single gasket Diaphragm Valve:
This variant employs a single diaphragm to achieve valve opening and closing through compression or tension forces. Characterized by a relatively simple and compact structure, single-diaphragm valves are well-suited for controlling low-pressure, medium-temperature fluids with general characteristics. They exhibit excellent sealing performance and durability.
Double gasket Diaphragm Valve:
Equipped with two diaphragms, this type is typically arranged symmetrically, one positive and one negative. The valve's operation is governed by the pressure differential of air or liquid between the two diaphragms. Double-diaphragm valves offer superior sealing performance and operational accuracy, making them ideal for stringent fluid control applications, such as high-purity fluids, corrosive media, or high-viscosity liquids.
Separated gasket Diaphragm Valve :
In this configuration, the diaphragm structure is divided into two independent chambers: upper and lower. An intermediate chamber exists between the upper and lower diaphragms, where the pressure within controls diaphragm movement. Separated diaphragm valves excel in terms of sealing performance, anti-clogging capabilities, and ease of maintenance.
Advantages and Applications:
Diaphragm valves possess several notable advantages, including reliable sealing performance, corrosion resistance, wear resistance, no leakage, no seepage, and ease of maintenance. These attributes render them particularly suitable for specialized working conditions involving corrosive media, high-viscosity liquids, suspended particles, and flammable/explosive substances. As a result, diaphragm valves find extensive use across various industries, including chemical engineering, petroleum, power generation, metallurgy, pharmaceuticals, and food/beverage production.
