A gate valve (1) When the fluid flows through the gate valve, it does not change the flow direction. When the gate valve is fully open, the drag coefficient is the smallest of all the valves, and the applicable aperture range and pressure temperature range are very wide. Compared with the same diameter globe valve, the installation of smaller size, and therefore is the most used chemical production plant type. (2) Gate valve handle clear rod, dark rod two: rod rod valve for more than two sets of the same equipment when the alternate switch, the particular benefit, the rod clearly marked the valve switch. (3) When the gate valve half open, the valve core easy to produce vibration, so the gate valve is only applicable to fully open or fully closed, not suitable for the need to regulate the flow of occasions. (4) gate valve body groove, it does not apply to the fluid containing solid particles. In recent years, with a mouth blowing valve can be applied to this situation. Second, stop valve (1) Globe valve is widely used in chemical plant valve. Its sealing performance is reliable, but also suitable for regulating the flow, usually installed in the pump outlet, regulating valve bypass flow meter upstream need to regulate the flow of the place. (2) When the fluid flows through the valve core to change the flow direction, so the pressure drop, while easy to deposit solid objects on the valve seat, it is not suitable for suspension. (3) Globe valve compared with the same caliber gate valve, larger, thus limiting its maximum caliber (DNl50 ~ 200). (4) Y-type stop-valve and angle-type stop valve compared with the ordinary through-valve, the pressure drop is small, and both angular valve to change the flow direction. (5) needle valve is also a stop valve, the spool is tapered, can be used for small flow fine-tuning or as a sampling valve. Three cocks, plunger valves, ball valves (1) The three functions are similar, are quick opening and closing of the valve. Spool has a horizontal hole, the liquid DC through the pressure drop is small, suitable for suspension or viscous liquid. Spool and can be made into the upper or the D-shaped channel and become three, four-way valve. Shape regular, easy to make jacketed valve for insulation, these types of valves can be more easily made of pneumatic or electric valve for remote control. (2) The difference between the three lies in the plunger valve, the working pressure of the ball valve is slightly higher. Four. Butterfly valve A certain degree of regulation, especially for large flow regulation, the use of temperature by the sealing material restrictions. Five check valve (1) The check valve is a valve to prevent reverse flow of fluid. Generally used to prevent pollution due to fluid backflow, temperature rise or mechanical damage. (2) commonly used spin-Kai, lift and ball three categories. Swing diameter than the latter two larger, can be installed in the horizontal pipe or vertical pipe, installed in the vertical pipe when the fluid should flow from bottom to top. Lifting and ball-type smaller caliber, and can only be installed on the horizontal pipe. (3) Non-return valve can only be used to prevent sudden backflow but poor sealing performance. Therefore, other measures should be taken for material strictly prohibited from mixing. (4) centrifugal pump inlet suction state, in order to maintain the liquid pump inlet pipe installed at the end of the valve is also a check valve. When the container is open, the bottom valve can be strained. Six diaphragm valve and pipe clamp valve When these two kinds of valves are used, the fluid contacts only the diaphragm or the hose without touching other parts of the valve body, and is particularly suitable for corrosive fluids or viscous liquids, suspensions and the like. However, the application is limited by the material of the diaphragm or hose. ã€Print】 ã€Close】