Does anyone know the main features and principles of diaphragm valves????

The main features and principles of HICHINE diaphragm valves.

The main advantage of the diaphragm valve is that its operating mechanism is separated from the medium path, which not only ensures the purity of the working medium, but also prevents the possibility of the medium in the pipeline impacting the working parts of the operating mechanism. In addition, there is no need for any form of individual sealing at the stem, except as a safety facility in the control of hazardous media. In diaphragm valves, since the working medium is only in contact with the diaphragm and the valve body, both of which can be made of a variety of different materials, the valve is ideal for controlling a wide range of working media, especially for ground media with chemical corrosiveness or suspended particles.

The operating temperature of the British standard diaphragm valve is usually limited by the material used in the diaphragm and body lining, and its operating temperature range is approximately 50 175 degrees. The diaphragm valve has a simple structure, consisting of only three main components: the valve body, the diaphragm and the bonnet assembly. The valve is easy to disassemble and repair quickly, and diaphragm replacement can be done on-site and in a short time.

The operating mechanism and the separation of the medium path make the diaphragm valve not only suitable for the production of food and medicine and health industry, but also for some difficult to transport and dangerous media. The wider application of synthetic rubber and engineering plastics, as well as a wider selection of valve body lining materials, make diaphragm valves widely used in various fields of modern industry. Classification of diaphragm valves According to the structural form, diaphragm valves can be divided into:

There are six types: house type, DC type, cut-off type, straight-through type, ram type and right-angle type; The connection form is usually flange connection; According to the driving mode, it can be divided into manual, electric and pneumatic three types, of which pneumatic drive is divided into three types: normally open, normally closed and reciprocating.

For fermentation, diaphragm valves, sterile residues, and globe valves are used to make them with purge holes.

The diaphragm valve is a pneumatic regulating valve that regulates the flow rate. The shut-off valve is a shut-off valve.

First of all, you should first look at the medium, temperature, pressure and other working conditions you are using to select the type.

Diaphragm valve (sheet type).

In the design of such valves, a diaphragm made of synthetic rubber is used to connect to the stem, and the valve is closed by pressing the diaphragm against a metal boss, which is part of the valve body.

Diaphragm valves are primarily used in low-pressure water pressures of 1400 kpag (200 psig or less) and are particularly suitable for systems containing sand and other solid particles.

The diaphragm valve is connected to the compression with an elastic diaphragm, the compression is operated by the valve stem to move up and down, when the compression is raised, the diaphragm is lifted high, forming a path, when the compression is lowered, the diaphragm is pressed on the valve body, and the valve is closed. This valve is suitable for breaking and throttling. Diaphragm valves are particularly suitable for transporting corrosive, viscous fluids, and the operating mechanism of this valve is not exposed to the transported fluid, so it will not be contaminated, no packing is required, and the stem packing part will not leak.

Globe valves are most suitable when good throttling control is required, such as a bypass line for the control valve or a small vent.

Advantages: The structure of the globe valve is relatively simple, and the manufacturing and maintenance are more convenient. The sealing surface is not easy to wear and abrasion, has good sealing and long life.

The disc stroke is smaller, the opening and closing time is shorter, and the valve height is smaller. Disadvantages: High flow resistance.

The starting and closing torque is large, and the opening and closing are more laborious. The direction of media flow is restricted.

The structure of the globe valve: 1Straight-through:

A common form of structure with the greatest fluid resistance. 2.DC type:

The fluid resistance is small, and it is mostly used for fluids containing solid particles or high viscosity. 3.Right Angle:

Small bore, high pressure.

The most prominent feature of the feature is that the diaphragm separates the lower valve body cavity from the upper valve cover cavity, so that the valve stem, valve disc and other parts located above the diaphragm are not corroded by the medium, and the packing sealing structure is omitted, and the medium leakage will not occur.

1. The diaphragm made of rubber or plastic and other soft seals has good sealing. Since the diaphragm is a wearing part, it should be replaced regularly depending on the characteristics of the medium.

2. Limited by the diaphragm material, the diaphragm valve is suitable for occasions with low pressure and relatively low temperature.

3. According to the structural form, the diaphragm valve can be divided into six types: house type, DC type, cut-off type, straight-through type, gate type and right-angle type; The connection form is usually flange connection; According to the driving mode, it can be divided into manual, electric and pneumatic three types, of which pneumatic drive is divided into three types: normally open, normally closed and reciprocating.

4.Generally, it should not be used in pipelines with temperatures higher than 60 degrees and conveying organic solvents and strong oxidizing media, nor should it be used in pipelines with higher pressure.

Thank you for your help, looking for it from somewhere else, I hope it helps.

Introduction Diaphragm valve is a special form of shut-off valve, which appeared in the 20th century of the 20th century.

Generation. Its opening and closing part is a diaphragm made of soft material, which separates the valve body cavity from the valve cover cavity and the driving parts, so it is called a diaphragm valve.

Diaphragm valve structure features:

The lower valve body cavity is separated from the upper valve cover cavity with a diaphragm, so that the valve stem, valve disc and other parts located above the diaphragm are not corroded by the medium, and the medium will not leak out, and the stuffing box sealing structure is omitted.

The diaphragm valve is made of soft sealing materials such as rubber or plastic, and the diaphragm has good sealing. Since the diaphragm is easily damaged, it should be replaced regularly according to the working conditions and the characteristics of the medium.

Due to the limitation of the diaphragm material, the diaphragm valve is suitable for applications where the low pressure temperature is not high.

It has good anti-corrosion properties.

(1) Low fluid resistance.

2) It can be used for media containing hard suspended solids; Since the medium is only in contact with the valve body and diaphragm, there is no need for stuffing box, there is no leakage problem of stuffing box, and there is no possibility of corrosion to the valve stem part.

3) It is suitable for corrosive, viscous and slurry media.

4) It cannot be used in situations with high pressure.

1. The rubber-lined diaphragm valve mold should be stored in a dry and ventilated room, and it is forbidden to stack it.

2. Both sides of the channel of the inventory valve must be sealed to prevent dirty things from entering the inner wall and damaging the sealing components. And avoid contact with raw oil or other flammable materials.

3. The processing surface of the rubber-lined diaphragm valve should be cracked and stained, and coated with anti-rust oil.

4. Do not paint grease objects on the surface of the rubber lining pipe layer or plastic diaphragm to prevent plastic solubilization and affect the service life of the valve.

5. During the storage period or the period of cessation of use, the counterclockwise spindle should be used to make the valve in full opening to prevent the diaphragm from losing its elasticity due to long-term stress.

6. During transportation or installation, the hoisting rope should not be knotted on the handle or valve seat. It is also forbidden to collide with other metal materials or hard objects to prevent damage to parts and linings.

7. Before construction, the operating conditions and substances of the pipeline should be carefully checked to see if they are consistent with the application field specified in this valve, so as to prevent unnecessary troubles caused by unreasonable model selection.