Plug valve is one type of valve which makes the plug with hole as its on-off part, and plug valve achieve its on-off action by the turning of plug and stem. Plug valve structure is simple, plug valve on-off is quick, and plug valve flow resistance is small. As one of the valve types which are used from early, plug valve does not only been replaced by other types of valves, such like ball valve, but also plug valve is used more and more widely in recent years. Plug valve inlet/outlet end design is double groove sealing ring structure. During the plug valve turning, the seal specific pressure between the plug seal pairs is changing gradually until the plug valve is full open or full close, the seal specific pressure is enough for plug seal pairs to achieve zero leakage. Double groove sealing ring not only can make PTFE sleeve fixed into the body without movement, but also can absorb micro deformations of the sleeve which is caused by changes in temperature. Meanwhile, the wiping action between the plug valve sleeve and plug extends the sealing surface service life. Plug valve sealing process is almost not affected by the pressure in the pipe. In the PTFE sleeve, it can adopt different materials of packing according to actual working temperature and medium.
Plug valve can be divided into sleeve type of plug valve, inverted pressure balance lubricated type of plug valve, lift type of plug valve, 3 way plug valve and 4 way plug valve.
Sleeve type of plug valve is applied to oil, chemical industry, medicine, power plant, etc. for cutting off or connecting the medium in the pipe. Sleeve type of plug valve medium temperature is -29~180℃. Sleeve type of plug valve structure is reasonable, sleeve type of plug valve seal is reliable, sleeve type of plug valve performance is good, and sleeve type of plug vale outline is nice. Sleeve type of plug valve seal is achieved though the sealing around the sleeve. There is not cavity in the sleeve type of plug valve for medium accumulation. Sleeve type of plug valve is applicable to working conditions where is easy to form dope and scale. Sleeve type of plug valve can be double-flow, so sleeve type of plug valve is very convenient for mounting. Sleeve type of plug valve materials and flanges ends dimensions can be selected according to actual working conditions.
Inverted pressure balance lubricated type of plug valve is applied to oil, chemical industry, medicine, power plant, etc. for cutting off or connecting the medium in the pipe. Inverted pressure balance lubricated type of plug valve medium temperature is -29~180℃. Inverted pressure balance lubricated type of plug valve structure is reasonable, inverted pressure balance lubricated type of plug valve seal is reliable, inverted pressure balance lubricated type of plug valve performance is good, and inverted pressure balance lubricated type of plug valve outline is nice. Inverted pressure balance structure on-off action is light. There is oil groove between the plug valve body and sealing surface, making it possible to fill in sealed grease with oil nipple, and increasing the Inverted pressure balance lubricated type of plug valve sealing performance. Inverted pressure balance lubricated type of plug valve materials and flanges ends dimensions can be selected according to actual working conditions.
Lifting type of plug valve is applied to oil, chemical industry, medicine, power plant, etc. for cutting off or connecting the medium in the pipe. Lifting type of plug valve medium temperature is -29~550℃. Lifting type of plug valve structure is reasonable, Lifting type of plug valve seal is reliable, Lifting type of plug valve performance is good, andLifting type of plug valve outline is nice. Lifting type of plug valve achieve its on-off in the condition of sealing surface is off, not result in the sealing wear. Lifting type of plug valve can be double-flow, so lifting type of plug valve is very convenient for mounting. Lifting type of plug valve materials and flanges ends dimensions can be selected according to actual working conditions.
When opening the lifting type of plug valve, turn the hand wheel firstly to lift the plug up; when the plug is off from the sealing surface, turn the hand wheel for 90°, making the plug flow port communicated with body port, achieving the plug valve open. When close the lifting type of plug valve, turn the hand wheel for 90°firstly, making the plug flow port vertical with body flow port. And then turn the hand wheel again, making the plug goes down, achieving lifting plug valve sealing.