Butterfly valve is suitable for what occasions? What are the selection principles?

         Butterfly valve is suitable for what occasions? What are the selection principles?

Butterfly valve, also called flap valve, is a simple structure of the regulating valve, but also can be used for low-pressure pipeline media switching control. Butterfly valve refers to the closing member (valve or butterfly plate) for the disk, rotating around the valve axis to achieve the opening and closing of a kind of valve, in the pipeline mainly play the role of cutting off and throttling. Butterfly valve opening and closing parts is a disc-shaped butterfly plate, in the valve body around its own axis rotation, so as to achieve the purpose of opening and closing or regulation. Butterfly valve is suitable for furnace. Gas. Natural gas. Liquefied petroleum gas. City gas. Hot and cold air. Chemical smelting and power generation and environmental protection and other engineering systems to transport a variety of corrosive and non-corrosive fluid media pipeline, used to regulate and cut off the flow of media. Non-corrosive fluid media pipeline, used to regulate and cut off the flow of media.

Butterfly valve for the occasion

Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipeline is relatively large, about three times that of the gate valve, when selecting the butterfly valve, the impact of the pipeline system by the pressure loss should be fully considered, and the robustness of the butterfly plate under the pressure of the pipeline medium should also be considered when it is closed. In addition, the operating temperature limitations of the elastic seat material at high temperatures must be considered.

The structure length and overall height of the butterfly valve is small, the opening and closing speed is fast, and has good fluid control characteristics, the structure principle of the butterfly valve is most suitable for the production of large diameter valves. When the butterfly valve is required to be used for flow control, the most important thing is to correctly select the size and type of butterfly valve so that it can work properly and effectively.

Generally, in throttling, regulating control and mud media, short structural length and fast opening and closing speed (1/4r) are required. Low pressure cut-off (small pressure difference), butterfly valve is recommended.

The butterfly valve can be used when the two-position adjustment, the shrinking channel, the low noise, the cavitation and gasification phenomenon, the small leakage to the atmosphere, and the abrasive medium.

When the butterfly valve is used under special working conditions, or when the seal is strict, or the wear is serious, the butterfly valve is used under low temperature (deep cooling) and other working conditions, it is necessary to use a special designed metal seal with a regulating device of three eccentric or double eccentric butterfly valve.

The middle line butterfly valve is suitable for fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and various acid and alkali and other pipelines that require complete sealing, zero gas test leakage, high life requirements, and a working temperature of -10~150℃.

The soft-sealed eccentric butterfly valve is suitable for bidirectional opening and closing and adjustment of ventilation and dust removal pipeline, and is widely used in metallurgy, light industry, electric power, petrochemical system gas pipelines and waterways.

Metal to metal wire seal double eccentric butterfly valve is suitable for urban heating, steam, water and gas, oil, acid and alkali pipelines, as a regulating and intercepting device.

In addition to being used as a large pressure swing adsorption (PSA) gas separation device program control valve, it can also be widely used in petroleum, petrochemical, chemical, metallurgy, electric power and other fields, and is a good alternative to gate valves, globe valves, etc.

Selection principle of butterfly valve

1. Because the butterfly valve is relative to the gate valve, the ball valve pressure loss is relatively large, so it is suitable for the pipeline system with low pressure loss requirements.

2. Because the butterfly valve can be adjusted by flow, it is suitable for selection in the pipeline that needs flow adjustment.

3. Due to the limitations of the structure and sealing materials of the butterfly valve, it is not suitable for high temperature and high pressure pipeline systems. The general operating temperature is below 300℃, and the nominal pressure is below PN40.

4. Because the butterfly valve structure length is relatively short, and can be made into a large diameter, so in the case of short structural length requirements or large diameter valves (such as DN1000 or more), the butterfly valve should be selected.

5. Since the butterfly valve can be opened or closed by rotating only 90°, it is appropriate to choose the butterfly valve when the opening and closing requirements are fast.