The structure of the diaphragm valve is quite different from the general valve. It is a new type of valve and a special form of cut-off valve. Its opening and closing part is a diaphragm made of soft material. The inner cavity of the cover and the driving part are separated and are now widely used in various fields. Commonly used diaphragm valves include rubber-lined diaphragm valves, fluorine-lined diaphragm valves, unlined diaphragm valves, and plastic diaphragm valves.

Diaphragm valve is composed of valve body, valve bonnet, valve disc, valve stem, diaphragm and other driving parts. It is a special form of shut-off valve. Its opening and closing parts are composed of a diaphragm made of a soft material inlaid with a metal valve clack, which separates the inner cavity of the valve body from the inner cavity of the valve bonnet and the driving parts. The most prominent feature of the diaphragm valve is that the diaphragm separates the inner cavity of the lower valve body from the inner cavity of the upper bonnet, so that the valve stem, valve clack and other parts located above the diaphragm are not corroded by the medium, which can ensure the purity of the medium and will not make the medium. leak.

Under normal circumstances, if it is not tightly closed, first check to see if the valve is closed in place. If it has been closed in place, there is still leakage and cannot be sealed, then check the sealing surface. If the vice-sealing pair can be disassembled, then take it out for grinding and test again. Of course, if it is still not closed tightly, then it must be returned to the factory for repair or replacement of the valve, so as not to affect the normal use of the valve and accidents such as working conditions.

Today, we talk about 2 Types industrial valve sealing type

The seal is also a very critical component in the valve. The sealing performance of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the medium. It is the most important technical performance index of the valve.

There are many factors that affect valve sealing, We can find there are 4 main elements.

mainly as follows:

1. Sealing structure

Under the change of temperature or sealing force, the structure of the vice-sealing part will change. Moreover, this change will affect and change the force between the vice-sealing part, thereby reducing the performance of the valve sealing.

It means that when the opened valve is suddenly closed, due to the inertia of the pressurized water flow, a water shock wave is generated and has a destructive effect. This is the “water hammer effect” in hydraulics, that is, positive water hammer.

The arrow marked on the valve body is the recommended pressure-bearing direction of the valve, not the flow direction of the pipeline medium. The valve with two-way sealing function may not be marked with an indicating arrow, or with an arrow, because the valve arrow refers to the recommended pressure direction. It is better to have one direction in the left and right or up and down directions.

Valve leakage has become one of the main leakage sources in the device, so it is very important to improve the valve’s anti-leakage capability. To prevent valve leakage, it is necessary to master the basic knowledge of valve sealing parts to prevent medium leakage-valve sealing, this is the most important thing.Principle of valve sealing

when selecting the valve stem material, it is necessary to ensure that the industrial valve stem has sufficient strength, good impact toughness, and corrosion resistance at the specified temperature. The industrial  valve stem is fragile, so attention should be paid to the machining performance and heat treatment performance of the material when selecting it.

Diaphragm valve: refers to a flexible membrane or combined diaphragm installed in the valve body and bonnet, and the closing part is a compression device connected with the diaphragm. The valve seat can be a weir shape or a straight through type.