Butterfly valve function purpose
Butterfly valve refers to the closing piece (disc or disc) for the disc, rotating around the valve shaft to open and close a valve, the main role in the pipeline to cut off and throttle.Butterfly valve opening and closing parts is a disc shaped disc, in the valve body around its own axis rotation, so as to achieve the purpose of opening and closing or regulation.Butterfly valves are usually less than 90° from full open to full close. Butterfly valves and butterfly rods do not have self-locking capability. In order to locate butterfly plate, worm gear reducer should be installed on the valve stem.Using worm gear reducer can not only make the butterfly plate with self-locking ability, stop the butterfly plate at any position, but also improve the operation performance of the valve.Industrial special butterfly valve features high temperature resistance, the applicable pressure range is higher, the valve nominal size is large, the body is made of carbon steel, the sealing ring of the valve plate USES metal ring instead of rubber ring.Large high temperature butterfly valve is manufactured by welding steel plate, mainly used for high temperature medium smoke duct and gas pipeline.
Butterfly valve suitable for the occasion
Butterfly valves are designed for flow regulation.Because the butterfly valve in the pipeline pressure loss is relatively large, it should also consider the closure of the butterfly plate under the pressure of the pipeline medium robustness.In addition, consideration must be given to operating temperature limitations of resilient seat materials at high temperatures.Butterfly valve structure length and overall height is small, fast opening and closing speed, and has good fluid control characteristics, butterfly valve structure principle is most suitable for the production of large diameter valves.When butterfly valves are required 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 medium, short structure length and fast opening and closing speed (1/4 turn) are required.Low pressure cut-off (low pressure difference), butterfly valve is recommended.
Butterfly valve can be used in the case of double-position regulation, narrow mouth ground channel, low noise, cavitation and gasification phenomenon, a small amount of leakage into the atmosphere, with abrasive media.
When the butterfly valve is used under special working conditions such as throttling regulation, strict sealing requirement, severe wear and low temperature (deep cold), special designed metal seal with regulating device for special triple eccentric or double eccentric butterfly valve shall be used.
The middle line butterfly valve is suitable for fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and all kinds of acid and alkali and other pipelines with complete seal, zero leakage in gas test, high life requirement and working temperature between -10 ℃ and 150 ℃.
The soft sealing eccentric butterfly valve is suitable for two-way opening and closing and adjustment of ventilation and dust removal pipelines, widely used in gas pipelines and waterways of metallurgy, light industry, electric power, petrochemical system, etc.
Metal to metal wire sealing double eccentric butterfly valve is suitable for city heating, gas supply, water supply and other gas, oil, acid and alkali pipelines, as a regulating and throttling device.
In addition to being used as a program control valve of large PSA gas separation unit, the metal to metal sealing triple eccentric butterfly valve can also be widely used in petroleum, petrochemical, chemical industry, metallurgy, electric power and other fields, as a good substitute for gate valve and globe valve.