Soft seal butterfly valve structure
What is the structure of a soft seal butterfly valve? The soft seal butterfly valve is a valve with a very simple structure, including a valve body, a valve stem, a valve plate, a valve seat, and a transmission device. The inside of the valve body is a cylindrical passage with a butterfly plate inside. The sealing pair of a soft-sealing butterfly valve is usually composed of a metal hard material and a non-metal soft material. The advantage of this kind of butterfly valve is that its valve seat is made of non-metallic soft material with certain strength, hardness and temperature resistance, so that when the butterfly valve is closed, the metal butterfly plate can be formed by extruding the non-metallic soft valve seat,form good sealing performance..
The seat material of the soft seal butterfly valve is made of EPDM and nitrile rubber, and PTFE fluorine plastic material. EPDM rubber is suitable for the media, such as salts, acids, metal coating solutions, water, etc., can adapt to working conditions of working pressure less than 2.5Mpa, -50 ~ 80 °C working temperature conditions. Nitrile rubber is suitable for medium, water, oil, waste liquid, etc. It can adapt to working conditions of working pressure less than 2.5Mpa and temperature of -10~90°C. The medium suitable for PTFE is heat-resistant, cold-resistant, general chemicals and solvents, and most of the liquids, and can be adapted to working conditions of working pressure ≤1.6Mpa and temperature -196~200°C. These three materials make the soft seal butterfly valve have excellent sealing performance, but also because of the limitations of the material itself, the soft seal butterfly valve cannot be used in high temperature and high pressure environment. In addition, the sealing material of the soft seal butterfly valve is not as good as the erosion resistance. Metal material, so the service life is shorter than the hard seal butterfly valve.
The butterfly valve structure of soft seal is usually in the middle line, it has two common connection modes, clamp type and flange type.Although the connection mode is different, but are figured out, by manipulating the transmission device, the valve spindle rotation, drives the butterfly plate movement, to control the opening and closing of the valve, butterfly plate rotation Angle of 0-90 °.The drive device of soft-seal butterfly valve, also called drive device, is commonly used for handle, turbine head, pneumatic head, electric head and so on.