Selection principle and application of butterfly valve

Butterfly valve, also called flap valve, is a simple structured regulating valve, which can also be used to switch and control low-pressure pipeline media. Butterfly valve refers to a valve whose disc (disc or disc) is a disc that rotates around the valve shaft to achieve opening and closing. It mainly cuts and throttles the pipeline. The butterfly valve opening and closing member is a disc-shaped butterfly plate that rotates around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting. Butterfly valve is suitable for pipelines that transport various corrosive and non-corrosive fluids in engineering systems such as generators, gas, natural gas, liquefied petroleum gas, city gas, hot and cold air, chemical smelting, and power generation and environmental protection. Media flow.

Butterfly valve is suitable for:

Butterfly valves are suitable for flow regulation. The pressure loss of the butterfly valve in the pipeline is relatively large, about three times that of the gate valve. Therefore, when selecting a butterfly valve, the piping system should be fully affected by the pressure loss, and the solidity of the butterfly plate under the pressure of the pipeline medium when closing should be considered. In addition, the limit of the operating temperature to which the elastic valve seat material must be subjected at high temperatures must also be considered by China high pressure butterfly valve manufacturer’s design.

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

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

In double-position adjustment, narrowed passage, low noise, cavitation and gasification, small leakage to the atmosphere, and butterfly valve can be used when there is abrasive medium.

Throttle adjustment under special working conditions, or strict sealing requirements, or severe wear, low temperature (deep cold) and other working conditions, the use of special design metal seal with three eccentric or double eccentric special adjustment device Butterfly valve.

The centerline butterfly valve is suitable for fresh water, sewage, sea water, brine, steam, natural gas, food, medicine, oil and various kinds of fresh water, sewage, sea water, brine, steam, natural gas, food, medicine, oil and various requirements that require complete sealing, zero gas test leakage, high life requirements Acid and alkali and other pipelines.

Soft seal eccentric butterfly valve is suitable for two-way opening and closing and adjustment of ventilation and dust removal pipelines. It is widely used in metallurgy, light industry, electricity, petrochemical system gas pipes and water channels.

Metal-to-metal wire sealed double eccentric butterfly valve is suitable for urban heating, steam, water supply and gas, oil, acid and alkali pipelines, as a regulating and shut-off device. China metal seat triple offset butterfly valve supplier has good experience for this kind valve design.

Metal-to-metal sealed triple eccentric butterfly valve is widely used in the fields of petroleum, petrochemical, chemical, metallurgy, power, etc. in addition to being used as a program control valve for large pressure swing adsorption (PSA) gas separation devices. Good substitute product.

Selection principle of butterfly valve:

1.   Because butterfly valves have larger pressure loss than gate valves, they are suitable for pipeline systems with less stringent pressure loss requirements.

2.  Because the butterfly valve can be adjusted with flow, it is suitable to use in the pipeline that needs to be adjusted

3.  Due to the limitation of the structure of the butterfly valve and the sealing material, it is not suitable for high temperature and high pressure pipeline system. The general working temperature is below 300 ° C, and the nominal pressure is below PN40.

4.  Due to the short structure of the butterfly valve, and it 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), butterfly valves should be used.

5.  Because the butterfly valve can be opened or closed only by rotating it by 90 °, it should be selected in the occasions with fast opening and closing requirements.