Globe valve stem axis and seat sealing surface perpendicular to. Stem opening or closing stroke is relatively short, and has a very reliable cut off action, making this valve is very suitable as a medium cut off or adjust and throttle. Once the valve flap of the globe valve is open, its contact between the valve seat and the flap sealing surface no longer contacts and has a very reliable cut-off action, making this valve ideal as a medium to cut or adjust Flow use. Once the stop valve is open, its valve seat and disc seal surface no longer have contact between, and therefore its sealing surface mechanical wear and tear less, as most of the valve seat and the disc valve is relatively easy to repair or replacement Sealing components without having to remove the entire valve from the pipeline, which for the valve and pipe welding is integrated into the case is very applicable. The flow direction of the medium as it passes through such a valve changes, so the shut-off valve has a higher flow resistance than the other valves. There are several commonly used stop valves: 1) Angular stop valves; in angle stop valves, the fluid only needs to be changed in one direction so that the pressure drop across this valve is less than that of conventional stop valves. 2) DC shut-off valve; In the DC or Y-type shut-off valve, the valve body flow path and the main flow channel into a slash, so that the flow of state damage than the conventional valve is smaller, so the pressure loss through the valve accordingly Small 3) Plunger globe valve: This type of globe valve is a variation of a conventional globe valve. In this valve, the disc and seat are usually designed based on the plunger principle. Polished valve plunger into a plunger connected with the stem, the seal is set by the plunger in the two elastic ring to achieve. The two elastomeric seals are separated by a collar, and the seal around the plunger is pressed firmly by the load exerted by the bonnet nut on the bonnet. Elastomeric seals are interchangeable and can be made in a wide variety of materials. The valves are mainly used to "open" or "close", but with a special form of plunger or special collar that can also be used to regulate flow .