1.Where the butterfly valve is applicable
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. sex. In addition, it is necessary to consider the limitation of the working temperature that the elastic valve seat material can withstand at high temperatures.
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 flow, the most important thing is to correctly select the size and type of the butterfly valve to make it 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 (1/4r). Low pressure cut-off (small pressure difference), butterfly valve is recommended.
In the case of two-position adjustment, narrowed passage, low noise, cavitation and vaporization, a small amount of leakage to the atmosphere, and abrasive media, butterfly valves can be used.
When using butterfly valves under special conditions such as throttling regulation, strict sealing requirements, severe wear, low temperature (cryogenic) and other operating conditions, a special design for triple eccentric or double eccentricity with a specially designed metal seal with adjustment device is required Butterfly valve.
The center line butterfly valve is suitable for fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and various products that require complete sealing, zero gas test leakage, high life requirements, and working temperature of -10~150℃. 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. It is widely used in gas pipelines and waterways in metallurgy, light industry, electric power, and petrochemical systems.
The metal-to-metal wire sealing 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-scale pressure swing adsorption (PSA) gas separation device program control valve, the metal-to-metal surface seal triple eccentric butterfly valve can also be widely used in petroleum, petrochemical, chemical, metallurgical, electric power and other fields. It is a gate valve, stop valve, etc. Good alternative product.
2.The selection principle of butterfly valve
1. Since the butterfly valve has a relatively large pressure loss compared to the gate valve, it is suitable for piping systems with less stringent pressure loss requirements.
2. Since the butterfly valve can be used for flow adjustment, it is suitable for use in pipelines that need flow adjustment.
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 piping system. Generally, the working temperature is below 300℃, and the nominal pressure is below PN40.
4. Since the structure length of the butterfly valve is relatively short and it can be made into a large diameter, the butterfly valve should be used in the occasions where the structure length is required to be short or the large diameter valve (such as DN1000 or more).
5. Since the butterfly valve can be opened or closed by only rotating 90°, it is better to choose the butterfly valve in the occasions that require fast opening and closing.
Post time: Oct-22-2021