Diaphragm valves are a specialized type of shut-off valve that emerged in the 1920s. Their operating mechanism consists of a diaphragm made of flexible material, which separates the valve body cavity from the valve bonnet cavity and the drive components, hence the name.

Characteristics of diaphragm valves are as follows:

The most prominent feature is that the diaphragm isolates the lower valve body cavity from the upper bonnet cavity. This protects components above the diaphragm—such as the valve stem and disc—from media corrosion, eliminates the need for packing seals, and prevents media leakage.

1. Diaphragms made of soft sealing materials like rubber or plastic provide good sealing performance. As the diaphragm is a wear part, it should be replaced periodically based on the characteristics of the medium.

2. Due to limitations in diaphragm material, diaphragm valves are suitable for low-pressure applications and environments with relatively moderate temperatures.

3. Diaphragm valves can be classified by structure into six types: dome-type, straight-through, globe-type, straight-through, gate-type, and right-angle-type; Connections are typically flanged. By drive type, they are categorized as manual, electric, or pneumatic, with pneumatic valves further subdivided into normally open, normally closed, and reciprocating types.

4. Generally unsuitable for pipelines exceeding 60°C or conveying organic solvents and strong oxidizing media. Pneumatic diaphragm valves are also inadvisable for high-pressure pipelines.

EG41J flanged rubber-lined diaphragm valves, including models EG41J-10 and EG41J-6 (British standard rubber-lined valves), are used to alter flow cross-sections and medium flow directions, providing functions such as flow guidance, shutoff, regulation, throttling, check, diversion, or overflow. These valves control the flow of fluids including water, steam, oil, gas, slurry, various corrosive media, liquid metals, and radioactive fluids.

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