(1) The plug valve has a direct flow of fluid, low resistance, convenient and rapid opening and closing.
(2) The plug valve is mainly used for cutting off, upgrading and changing the flow direction of the medium in the pipeline. It is easy to adapt to a multi-channel structure, so that one valve can obtain two, three, or even four different flow channels, which can simplify the design of the piping system, reduce the amount of valve gates and some connection accessories required in the equipment.
(3) The plug valve is the earliest valve used by people in history. Because of its simple structure, rapid opening and closing (the plug can rotate 1/4Q circle to complete the opening and closing action), the operation is convenient, the fluid resistance is small, and it is still widely used. Mainly used for low pressure, small diameter and low medium temperature.
(4) According to the structural characteristics of the plug valve and the functions that can be achieved in design, it can be selected according to the following principles.
①It is used to distribute the medium and change the flow direction of the medium. Its working temperature is not higher than 300℃, the nominal pressure is PN≤1.6MPa, and the nominal diameter is not more than 300mm. It is recommended to use a multi-channel plug valve.
②It is recommended to use austenitic stainless steel, tight-fitting conical plug valves for equipment and pipelines in food companies such as milk, juice, beer, and pharmaceutical factories.
③In the branch, refining and cleaning equipment for oilfield exploitation, natural gas field exploitation, and pipeline transportation, the nominal pressure level is not greater than Class300, and the nominal diameter is not greater than 300mm. Oil-sealed conical plug valves are recommended.
④In the branch, refining and cleaning equipment for oilfield exploitation, natural gas exploitation, and pipeline transportation, the nominal pressure level is not greater than Class7500, the nominal diameter is not greater than 900mm, and the working temperature is not greater than 340℃. Oil-sealed conical plug valves are recommended.
⑤In the large-scale chemical industry, pipelines and equipment containing corrosive media require fast opening or closing speed. For nitric acid-based media, a PTFE sleeve-sealed conical plug valve can be used; For acetic acid-based media, Crl8Nil 2M02Ti stainless steel inlaid polytetrafluoroethylene sleeve sealing conical plug valve can be used.
⑥ In the pipeline and equipment of the gas, natural gas, and HVAC system, the nominal diameter is not more than 200nm, and the packing type conical plug valve should be selected.