A butterfly valve refers to a type of valve in which the closing element (a disc or disc) is a disc that rotates around the valve axis to achieve opening and closing. Butterfly valves are suitable for flow regulation, as the pressure loss of butterfly valves in pipelines is relatively great, about three times that of gate valves. Therefore, when selecting a butterfly valve, the impact of pressure loss on the pipeline system should be fully considered, and the firmness of the butterfly plate to withstand the pressure of the pipeline medium when closed should also be considered. In addition, it is necessary to consider the limitations of the working temperature that the elastic valve seat material can withstand at high temperatures. To know where butterfly valves are applied, the first thing to know is the characteristics and advantages of butterfly valves.

Characteristics
Butterfly valves not only have simple structure, small volume, light weights, low material consumption, small installation sizes, small driving torque, simple and fast operation, but also have good flow regulation and sealing. A butterfly valve is one of the fastest developing valves in the past decade.

Butterfly valves are widely used and are developing towards high temperatures, high pressure, large diameters, good sealing performance, long service life, excellent regulation, and one valve with multiple functions. Their reliability and other performance indicators have reached a high level.

Advantages
1. Butterfly valves have the characteristics of simple structure, small volume, light weights, low material consumption, small installation sizes, fast opening and closing,  reciprocating rotation at an angle of 90 degrees, and small driving torque. Butterfly valves are used to cut off, connect, and regulate the medium in pipelines, and have good fluid control and sealing.
2. The butterfly valve has good sealing and good regulating performance.
3. The streamlined design of the butterfly plate reduces fluid resistance loss and is an energy-saving product.
4. The valve stem has a through rod structure, which has undergone quenching and tempering treatment, and has good comprehensive mechanical properties, corrosion resistance, and scratch resistance. When the butterfly valve is opened and closed, the valve stem only rotates without lifting, and the packing of the valve stem is not easily damaged, ensuring reliable sealing.
5. The connection methods include flanges, clamping, butt welding, and lug clamping.
6. The driving forms include manual, worm gear transmission, electric, pneumatic, hydraulic, electro-hydraulic linkage and other execution mechanisms, which can achieve remote control and automated operation.
 
When do we use butterfly valves?
1. Usually, it is recommended to use butterfly valves in throttling, regulating control, and water media, short structural length, fast opening and closing speed (1/4 turn),  and low pressure cutoff (small pressure difference).
2. When using butterfly valves under special operating conditions such as throttling adjustment, strict requirements for sealing, severe wear, low temperatures, etc., special designed metal sealing belt adjustment devices with three or two eccentricities are required.
3. The center line butterfly valve is suitable for fresh water, sewage, seawater, saline water, steam, natural gas, food, medicine, oil, and various acid-base and other pipelines that require complete sealing, zero gas leakage during gas testing, long service life, and operating temperatures between -10℃ and 80℃.
4. Soft seated eccentric butterfly valves are suitable for bi-directional opening and closing and adjustment of ventilation and dust removal pipelines, and are widely used in gas pipelines and waterways in metallurgical, light industry, power, and petrochemical systems.
5. The metal to metal seated double eccentric butterfly valve is suitable for urban heating, gas supply, water supply, gas, oil, acid and alkali pipelines, as a regulating and throttling device.