Diaphragm valve (uses of diaphragm valves)

Generally, the diameter of such valves is small, and the medium used is mainly liquid or slurry. Due to its effective separation of the medium from the valve body, the fully lined diaphragm valve is well suited for use with corrosive media.

It is mainly used on anti-corrosion pipes and materials.

Diaphragm valves use an elastic diaphragm to prevent fluid from passing through, and their valve stem does not come into direct contact with the medium, so a packing box is not required for the valve stem. It has characteristics similar to those of a pinch valve: there are no moving parts that can block the flow, and no gaps exist. The applications of diaphragm valves are the same as those of clamp valves; they are suitable for use in pipelines transporting gases, liquids, viscous fluids, and corrosive media, including in food and pharmaceutical systems ； Its operating pressure and temperature range are related to the structural material of the valve.

A diaphragm valve is a special type of shut-off valve that appeared in the 1920s. Its operating element is a diaphragm made of a soft material, which separates the interior cavity of the valve body from the interior cavity of the valve cover as well as from the driving components; hence it is called a diaphragm valve. 　　The characteristics of diaphragm valves are as follows: The most prominent feature is that the diaphragm separates the lower chamber of the valve body from the upper chamber of the valve cover, preventing components such as the valve stem and valve disc located above the diaphragm from being corroded by the medium. This eliminates the need for a packing seal mechanism, and it also prevents any leakage of the medium. 　　1. Diaphragms made from soft sealing materials such as rubber or plastic offer good sealing performance. Since the diaphragm is a vulnerable component, it should be replaced regularly depending on the properties of the medium. 　　2. Limited by the diaphragm material, diaphragm valves are suitable for low-pressure and relatively low-temperature applications. 　　3. Diaphragm valves can be classified into six types based on their structural design: roof type, straight-through type, globe type, direct-through type, gate type, and right-angled type ； The connection method is usually flange connection ； Based on the driving method, they can be divided into manual, electric, and pneumatic types; among the pneumatic types, there are normally open, normally closed, and reciprocating types. 　　4. It is generally not suitable for use in pipelines where the temperature is above 60 degrees, or in pipelines that transport organic solvents and strong oxidizing agents. Pneumatic diaphragm valves should also not be used in pipelines under high pressure.

The diaphragm pumps made in China are of better quality those from Chongqing Shipyard, though they don’t look good； Among foreign ones, there’s Ferrova from Germany – amazing!

Diaphragm valves are mainly used in environments with corrosive media. Apart from the diaphragm, the valve body and valve stem of a diaphragm valve do not come into contact with the internal medium, so they are not subject to corrosion. Moreover, diaphragm valve maintenance is also convenient; the diaphragm can be replaced directly without the need for grinding.

In our chemical plant, 20% to 30% of the hydrochloric acid pipelines are equipped with diaphragm valves

Diaphragm valves are mainly used for corrosion protection. I wonder if anyone has detailed schematic diagrams of diaphragm valves?

This post was last edited by Keep running on 2016-11-20 10:26. A diaphragm valve is a special type of shut-off valve; its closing element is a diaphragm made of a soft material, which separates the interior volume of the valve body from the interior volume of the valve cover as well as from the driving components. The most prominent feature of a diaphragm valve is that the diaphragm separates the inner cavity of the lower valve body from the inner cavity of the upper valve cover, preventing components such as the valve stem and valve disc located above the diaphragm from being corroded by the medium. This eliminates the need for a packing seal mechanism, and it also prevents any leakage of the medium. 1. Diaphragms made from soft sealing materials such as rubber or plastic offer good sealing performance. Since the diaphragm is a vulnerable component, it should be replaced regularly depending on the properties of the medium. 2. Limited by the diaphragm material, diaphragm valves are suitable for low-pressure and relatively low-temperature applications. 3. Diaphragm valves are suitable for various liquids such as acids, alkalis, and muds (for details, please refer to the relevant documentation). 4. Common diaphragm valves include: weir-type (roof-type) diaphragm valves, straight-through diaphragm valves, and parallel-flow diaphragm valves ； The connection method is usually flange connection ； Based on the driving method, they can be divided into manual, electric, and pneumatic types; among the pneumatic types, there are normally open, normally closed, and reciprocating types. Please contact if necessary