The plunger stop valve is simple and scientific in structure, safe and reliable, especially easy to open and close. It has the advantages of light and quick opening and closing as compared with the plunger valve. The sealing performance is unique and non-leaky. The piston has a multi-layer structure of metal and nonmetal sealing Of the double-effect, one-piece seat (liner) radial tapered sealing surface, high height, large contact area, good performance, piston ring according to different media of choice of materials to fully improve its use of the range, high temperature , Wear-resistant, corrosion-resistant, resilient performance, etc., after a long period of use, the piston ring wear adjustable when the pressure can increase the original state. Plunger stop valve repair replacement piston ring technology is simple and convenient, the valve body is not required to detach the pipe is stopped after the gas valve cover assembly can replace the replacement of the new piston ring and other features of the repetitive use. Its principle: the plunger valve consists of the valve body, valve cover, gland, valve stem, valve plug, valve plug cover, piston ring, integral cylinder (valve seat) stem nut, plain bearing, hand wheel, bevel gear Components, as a result of the rotation of the wheel lift rod-type piston piston so that it moves up and down between the inside and outside the cylinder to complete its closing and opening. Plunger block valve liner structure Conical Cylinder liner (seat) conical circularly welded according to the applicable medium, respectively, stainless steel alloy or hard alloy, surfacing layer hardness to HRC40, boring and grinding . Sealing structure of valve plug and piston ring with a multi-layer metal and non-metallic seal composition, when a piston ring wear and tear in the long-term use of the operation has been adjusted to zero pressure regulator has failed, so the second metal cutoff Taper piston plays the role of sealing at the same time, so the life of the plunger stop valve up to several times the normal valve, so in the use of the process without special maintenance and does not leak, to achieve a more open drain five leakage devices The choice of saving energy to reduce labor and environmental pollution has obvious applications.