Electric butterfly valve installation and maintenance

1, in the installation, the valve to stop in the closed position. 2, the opening position should be determined by the rotation angle of the disc. 3, with bypass valve butterfly valve, open the bypass valve should be opened before. 4, should be installed according to the manufacturer's installation instructions, the weight of the butterfly valve, should be set up a solid foundation. Butterfly valve butterfly valve installed in the pipe diameter direction. In the butterfly valve body cylindrical channel, the disc-shaped disc rotates about the axis, the rotation angle is between 0 ° -90 °, when rotated to 90 °, the valve is fully open. Butterfly valve structure is simple, small size, light weight, only a few components. And just turn 90 ° to quickly open and close, easy to operate, while the valve has good fluid control features. When the butterfly valve is fully open, the thickness of the disc is the only resistance to the flow of the medium through the valve body, so the pressure drop across the valve is small and therefore has good flow control characteristics. Butterfly valve seal and metal seal two types of seal. Flexible sealing valves, seals can be embedded in the body or attached to the butterfly plate around. Valves with metal seals generally have a longer life than elastomeric valves, but are harder to seal completely. Metal seals can adapt to higher operating temperatures, while flexible seals have temperature-limited defects. If the butterfly valve is required to be used as a flow control, the main choice is the correct size and type of valve. The structural principle of the butterfly valve is especially suitable for making large diameter valves. Butterfly valve not only in the oil, gas, chemicals, water treatment and other general industry has been widely used, but also used in thermal power station cooling water system. Commonly used butterfly valve clamp butterfly valve and flange two. The butterfly valve on the folder is to use double-headed bolts to connect the valve between the two pipe flanges, flanged butterfly valve is equipped with a flange on the valve, with bolts on both sides of the valve flange connected to the pipe flange. Butterfly Valve Structure and Problems Existing in Use At present, butterfly valves, as a kind of components used to realize on-off and flow control of pipeline system, have been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. In the well-known butterfly valve technology, the sealing structure adopts the sealing structure, the sealing material is rubber, polytetrafluoroethylene and the like. Due to the structural characteristics of the restrictions, do not meet the high temperature, high pressure and corrosion-resistant, anti-wear and other industries. A more advanced butterfly valve is a three-eccentric metal seal butterfly valve, the valve body and the valve seat as a single component, seat sealing surface layer surfacing temperature, corrosion resistant alloy material. Multi-layer soft stacked ring fixed to the valve plate, this butterfly valve compared with the traditional butterfly valve with high temperature, light operation, opening and closing without friction, closed with the torque of the transmission mechanism to compensate for increased sealing, improved butterfly valve The sealing performance and extend the service life of the advantages. As the multi-layer soft and hard stacked ring fixed to the valve plate, when the valve plate normally open state of the sealing surface to form a positive erosion, sheet metal sandwich in the soft seal by the erosion, directly affect the sealing performance. Construction, installation points 1), installation location, height, direction of import and export must meet the design requirements, pay attention to the direction of the flow of media should be consistent with the direction of the arrow marked by the body, the connection should be strong and tight. 2), the appearance of the valve must be installed before the inspection, the valve nameplate should be consistent with the current national standard "General Valve Flags" GB 12220 requirements. For the working pressure is greater than 1.0 MPa and the main pipe to play the role of cut-off valve, the installation should be carried out before the intensity and tightness test, qualified after the standard use. Strength test, the test pressure of 1.5 times the nominal pressure, the duration of not less than 5min, valve housing, packing should be no leakage as qualified.