Cut-off valve according to the direction of the channel: 1) Straight-through valve: In the DC or Y-valve, the body of the flow path and the main flow into a slash, so that the flow of damage than the conventional valve to be small, The pressure loss through the valve is also correspondingly small. 2) Angle stop valve: In the angle stop valve, the fluid only needs to change direction once, so that the pressure drop through this valve is smaller than that of the conventional structure. American standard bellows globe valve zdaj41w type 4) plunger stop valve: This form of the globe valve is a conventional stop valve variant. 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 .