Marine wafer type hydraulic butterfly valve

Butterfly valve, also known as flap valve, is a simple structure of control valve, can be used for low-pressure pipeline medium switch control butterfly valve refers to the closing part (disc or butterfly plate) as a disc, rotating around the valve shaft to open and close a valve.

The valve can be used to control the flow of air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive medium. It is mainly used for cutting off and throttling on the pipeline. The opening and closing part of butterfly valve is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting.

Butterfly valve is a kind of valve that uses disc type opening and closing parts to rotate about 90 ° to open, close or regulate medium flow. Butterfly valve is not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, simple and rapid in operation, but also has good flow regulation function and closing sealing characteristics at the same time. It is one of the fastest developing valve varieties in the past ten years. Butterfly valves are widely used. The variety and quantity of its use is still expanding, and it is developing to high temperature, high pressure, large diameter, high sealing, long life, excellent regulating characteristics, and multi-function of one valve. Its reliability and other performance indexes have reached a high level.

With the application of chemical resistant synthetic rubber in butterfly valve, the performance of butterfly valve can be improved. Synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming and low cost, and can be selected according to different requirements to meet the operating conditions of butterfly valve.

Polytetrafluoroethylene (PTFE) has strong corrosion resistance, stable performance, not easy to aging, low friction coefficient, easy forming, stable size, and its comprehensive performance can be improved by filling and adding appropriate materials to obtain butterfly valve sealing material with better strength and lower friction coefficient, which overcomes the limitations of synthetic rubber. Therefore, polytetrafluoroethylene (PTFE) is the representative of polymer polymer polymer Composite materials and their filling modified materials have been widely used in butterfly valves, so that the performance of butterfly valves has been further improved. Butterfly valves with wider temperature and pressure range, reliable sealing performance and longer service life have been produced.

In order to meet the requirements of high and low temperature, strong erosion, long life and other industrial applications, metal sealed butterfly valve has been greatly developed. With the application of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance and high strength alloy materials in butterfly valves, metal sealed butterfly valves have been widely used in high and low temperature, strong erosion, long service life and other industrial fields. Butterfly valves with large diameter (9 ~ 750mm), high pressure (42.0mpa) and wide temperature range (- 196 ~ 606 ℃) have appeared, which makes the butterfly valve technology reach a new level 。

The butterfly valve has small flow resistance when it is fully opened. Therefore, when the diameter of butterfly valve is between 70 ° and 15 ° it can be widely used in the field of control.

As the butterfly valve disc movement with wiping, so most butterfly valves can be used with suspended solid particles of the medium. According to the strength of the seal, it can also be used for powder and granular media.

Butterfly valves are suitable for flow regulation. Since the pressure loss of butterfly valve in the pipe is relatively large, which is about three times of that of gate valve, the influence of pressure loss on pipeline system should be fully considered when selecting butterfly valve, and the strength of butterfly plate bearing pipeline medium pressure when closing should be considered. In addition, the working temperature limit of resilient seat material at high temperature must be considered.

The structure 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 structure principle of butterfly valve is most suitable for making large diameter valve. When the butterfly valve is required to be used 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, fast opening and closing speed and low pressure cut-off (small differential pressure) are required. Butterfly valve is recommended. Butterfly valve can be used in double position adjustment, reduced diameter channel, low noise, cavitation and vaporization phenomenon, small leakage to the atmosphere and abrasive medium. Throttling adjustment under special working conditions, or strict sealing, severe wear and low temperature (cryogenic) working conditions are required.