The valve is the control equipment in the fluid pipeline system. Its main function is to isolate equipment and piping system, regulate flow, prevent backflow, regulate and discharge pressure and other functions to protect the normal operation of pipeline equipment.

    Valve industry so far, we have produced a full range of gate valves, globe valves, butterfly valves, ball valves, regulating valves, plug valves, diaphragm valves, check valves, safety valves, pressure reducing valves, traps and shut-off valves, such as 12 categories, more than 3000 models, more than 4000 specifications of valve products. In the face of so many valve varieties and so complex a variety of conditions, from a pipeline system to choose the most suitable valve is very important, so, understanding the characteristics of the valve and the selection of the steps and basis for the valve has become crucial.

    The function of the valve valve is the control device of the fluid pipeline, which plays an important role in the production process of all walks of life. In the water supply industry is an indispensable control device. 

1. Connecting and truncating media; 

2. Prevent backflow of media; 

3. Adjust medium pressure, flow, temperature, liquid level, etc. 

4. Separating, mixing, or distributing media; 

5. To prevent the media pressure.

    Valve classification by purpose and function classification: 1. Truncation class: mainly used for truncating or connecting medium flow. Such as gate valve, globe valve, ball valve, disc valve, plug valve, diaphragm valve. 

1. Check class: Used to prevent backflow of media. Including a variety of structures check valve.

2. Regulation class: regulation medium pressure and flow, such as pressure relief valve, pressure relief valve, throttle valve.

3. Safety class: in the media pressure exceeds the specified value, used to discharge excess media, to ensure the safety of piping systems and equipment. 

4. Distribution class: change the media flow direction, distribution media, such as three-way valve, (shunt valve, combined valve) distribution valve, (two five-way solenoid valve) spool valve. Special use: such as trap, vent valve, drain valve, bottom valve, etce exceeding the specified value, to ensure the safe operation of the pipeline or installation.

Sort by pressure：

1.Vacuum valves-operating pressure below atmosphere 

2.low pressure valves-nominal pressure PN less than 16 mpa 

3.medium pressure valves-nominal pressure PN 2.5-6.4 mpa

4.high preessure valves-nominal pressure PN 10.0-80.0 mpa

5.ultrahigh pressure valves-nominal pressure PN greater than 100 mpa

With the pipeline connection can be divided into: 

1. Flanged valves: valves with flanged body and flanged piping. 

2. Threaded valves: valves with threaded body and threaded pipe connections.

3. Welding connection valve: valve body with a weld, and the pipeline to use welding connection valve.

4. Clamp connection valve: valve body with a clamp, and the pipeline to use the clamp connection valve.

    According to the classification of valve body materials: non-metallic valves: such as ceramic valves, FRP valves, plastic valves, metal valves: such as cast iron valves, carbon steel valves, cast steel valves, low-alloy steel valves, high-alloy steel valves and copper alloy valves, etc.