Butterfly valves are suitable for flow regulation. Since the pressure loss of the butterfly valve in the pipeline is relatively large, it is about three times that of the gate valve. Therefore, when selecting the butterfly valve, the influence of the pressure loss of the pipeline system should be fully considered, and the strength of the butterfly plate to withstand the pressure of the pipeline medium should also be considered when it is closed. In addition, it is necessary to consider the limitation of the working temperature of the elastic seat material at high temperature.
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-diameter valves. When the butterfly valve is required to control the flow rate, 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 required to be short, and the opening and closing speed is fast (1/4 revolution). Low pressure cut-off (small pressure difference), butterfly valve is recommended.
Butterfly valve can be used when two-position adjustment, narrow passage, low noise, cavitation and vaporization phenomenon, a small amount of leakage into the atmosphere, and abrasive media.
When the butterfly valve is used under special conditions such as throttling adjustment, strict sealing, or severe wear, low temperature (cryogenic), etc., it is necessary to use a three-eccentric or double-eccentric butterfly valve with a specially designed metal seal with an adjustment device .
The concentric butterfly valve is suitable for fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and other products that require complete sealing, zero gas test leakage, high life requirements, and working temperature of -10℃～150℃. Kind of acid-base and other pipelines.
The soft-sealed eccentric butterfly valve is suitable for the two-way opening and closing and adjustment of ventilation and dust removal pipelines, and is widely used in gas pipelines and waterways in metallurgy, light industry, electric power, and petrochemical systems.
Metal-to-metal sealing double eccentric butterfly valve is suitable for urban heating, gas, water supply and other gas, oil, acid and alkali pipelines, as a regulating and throttling device.
In addition to being used as a large-scale pressure swing adsorption (PSA) gas separation device program control valve, the metal-to-metal seal triple eccentric butterfly valve can also be widely used in petroleum, petrochemical, chemical, metallurgy, electric power and other fields. It is a good gate valve and stop valve. replacement product.
Selection principle of butterfly valve:
01 Since the butterfly valve has a relatively large pressure loss compared to the gate valve and ball valve, it is suitable for piping systems with less stringent pressure loss requirements
02 Since the butterfly valve can be used for flow adjustment, it is suitable for use in pipelines that need flow adjustment.
03 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 piping system. Generally, the working temperature is below 300℃, and the nominal pressure is below PN40
04 Since the structure length of the butterfly valve is relatively short and it can be made into a large size, it is better to choose a butterfly valve in an occasion where the structure length is required to be short or a large orifice valve (such as DN1000 or more.
05 Since the butterfly valve can be opened or closed by only rotating 90°, the butterfly valve should be selected in the occasions that require fast opening and closing.
