The soft-sealed butterfly valve has simple structure, small size, light weight, low material consumption, small installation size, rapid switch, 90° reciprocating rotation, small driving torque; and also has good flow adjustment function and closing sealing characteristics at the same time. In the application areas of caliber and medium and low pressure, butterfly valve is the dominant valve form.
When the butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be inlaid on the valve body or attached to the periphery of the butterfly plate. Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. The metal seal can adapt to higher working temperature, while the elastic seal has the defect of being limited by temperature. If the butterfly valve is required to be used as a flow control, the main thing is to correctly select the size and type of the valve. The structure principle of butterfly valve is especially suitable for making large-diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, and water treatment, but also used in cooling water systems of thermal power stations.
The butterfly plate of the soft sealing butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened. The characteristics of the new high-life stainless steel butterfly valve and the problems in the use of the butterfly valve, this type of valve should generally be installed horizontally in the pipeline. According to the connection mode, the soft sealing butterfly valve can be divided into flange soft sealing butterfly valve, wafer soft sealing butterfly valve, welding soft sealing butterfly valve.
The function of the high vacuum butterfly valve: a working cycle of vacuum freeze dryers is generally about 24 hours, and some vacuum freeze dryers work for 72-100 hours. Power outages and water failures may occur during the entire working period (electricity is the power of the unit The source and water are the cooling source of the refrigeration system).
