There are many types of plug valves, and there are a variety of classification methods. 1. According to the structure is divided into: cylindrical plug, conical plug valve 2. According to the sealing surface material classification (1) non-metallic sealing material plug valve. Sealing surface material using PTFE, rubber, nylon, para-polystyrene, flexible graphite and other soft material plug valve. (2) metal sealing material plug valve. Sealing material is made of metal to metal stopcock. (3) oil film sealing plug valve. Sealing by pressing the seal between the fat seal to achieve the plug valve. 3. Classified by work pressure (1) Vacuum stopcock. Working pressure is lower than the standard atmospheric pressure plug valve. (2) low-pressure plug valve. Nominal pressure ≤ 1.6MPa or nominal pressure level% Class150 of the plug valve. (3) Medium-pressure plug valves. Nominal pressure of 2.5 ~ 6.4MPa or nominal pressure level of Class150-400 plug valves. (4) high-pressure plug valve. Nominal pressure 10.0-80.OMPa or nominal pressure level Class600-2500 of the plug valve. 4. Classified by working temperature (1) High temperature plug valve. t> 450 ℃ plug valve. (2) in the temperature stopcock valve. 120 ℃ <t ≤ 450 ℃ stopcock. (3) Normal temperature plug valve. -40 ℃ <f ≤ 120 ℃ stopcock. (4) low-temperature plug valve. -100 ℃ <t ≤ -40 ℃ stopcock. (5) ultra-low temperature plug valve. t ≤-100 ℃ plug valve. 5. Classification by connection (1) Flange connection plug valve. (2) Internal thread connection plug valve. (3) male screw plug. (4) welding connection plug valve. (5) clamp connection plug valve. (6) Sleeve connection plug valve. Stopcock sealing principle Depending on the structure of the stopcock and the sealing material, the stopcock can be sealed with a metal seal, a grease seal, and a non-metallic soft material. Metal seal, not only requires lower surface roughness and more accurate shape and location of tolerances, but also requires a higher seal than the pressure, in order to achieve the required sealing performance. Sealing with grease and non-metallic soft materials requires a more accurate geometry. According to the above requirements, there are many kinds of seal design, the sealing principle is not the same. Search Keyword: More Valve Technical Articles Valve Products Supply Information