平板闸阀按照使用场合和用途可分为带导流孔平板闸阀、无导流孔平板闸阀、油田平板闸阀、燃气平板闸阀及管线平板闸阀等。
平板闸阀的工作原理:双重密封、自动泄压、免维护
1、阀门内部压力相当时，闸板处于闭合状态，阀座表面PTFE密封环形成初始密封，每次阀门开或关时，阀座圈能清洁闸板两侧.
2、对阀门施加管理压力时，压力作用于闸板，迫使它贴近出口阀座上PTFE环，压缩它直到闸板停在钢制阀座上，这样，就形成了双重密封，首先是PTFE对金属密封，然后是金属对金属密封，阀座也被牢固地捡到凹槽，在这一点，O形圈阻止任何后部介质流.
3、阀体压力泄放后，形成进口密封，管道压力作用于进口阀座，使其移向闸板，这时形成PTFE对金属的密封，同时，O形圈与阀座凹槽形成紧密的密封.
4、阀门自动泄放多余的压力，当阀体压力大于管道压力时，由于热膨胀，进口阀座推向凹槽，阀体内多余的压力在阀座与闸板之间泄放到管道中.
Flat valve principle of work:Double seal, automatic pressure release, free maintenance
1.Valve internal pressure quite, the disc in closing state, seating surface PTFE ring form the initial seal, every time open or close the valve, the valve seat ring can clean on both sides of the gate.
2.The valve pressure on management, the pressure in the role of ram, force it to close to export seat PTFE ring, compression of it until the disc stop in steel seat, so, they form a double seal, first is PTFE to metal seal, and then is the metal to metal seal, seat was also firmly pick up to groove, at this point, to prevent the o-ring any medium flow.
3.Pressure from the body of the valve bleeder, form the imported seal, line pressure in the role of import the seat, make its move to ram, then form of metal sealing PTFE, and at the same time, with the seat o-ring seal grooves form a tight.
4.Automatic relief valve put extra pressure, when the body pressure than the pipe pressure, due to thermal expansion, import seat into the groove, body excess stress in the seat and disc discharge pipeline in between.