The characteristics of various types of valves and the scope of application

1. Gate valve

(1) Flow through the valve does not change the flow direction, when the valve is fully open when the resistance coefficient is almost the smallest of all valves, and the applicable caliber range, pressure and temperature range is very wide. Compared with the same diameter of the globe valve, the installation of small size, and thus chemical production is the most used type of device.

(2) Gate valve clear rod, dark rod two: Ming Barrier valve for more than two sets of the same equipmen t in the alternate switch, particularly favorable, the pole can clearly marked the valve switch.

(3) When the valve half open, the valve core is easy to produce vibration, so the gate valve is only applicable to fully open or fully closed, not suitable for the need to adjust the flow of the occasion.

(4) Gate valve body groove, so does not apply to the fluid containing solid particles. In recent years, there is a gate valve with a blow port can be applied to this situation.

2. Globe valve.

(1) Globe valve is a chemical device widely used valve. It is reliable sealing performance, but also for adjusting the flow, usually installed in the pump outlet, the upstream flow control valve to adjust flow, such as the Department.

(2) fluid flow through the valve core to change the flow direction, so the pressure drop, while easy to deposit solid in the valve seat, it is

Not suitable for suspensions.

(3) globe valve and the same caliber gate valve than the larger, thus limiting its maximum diameter (maximum DN150 ~ 200).

(4) Y-type globe valve and angle valve and ordinary straight-through valve, the pressure drop is smaller, and angle-type valve both change the flow function.

(5) needle valve is a kind of globe valve, the valve core is conical, can be used for small flow fine-tuning or as a sampling valve.

3. Plug, plunger valves, ball valves.

(1) The three functions are similar, can quickly open and close the valve. Spool has a horizontal opening, the liquid through the DC, the pressure drop is small, suitable for suspension or viscous liquid. Spool can be made into L-shaped or T-shaped channel and become three-way, four-way valve. Shape, easy to make jacketed valve for the need to heat the situation, these types of valves can be more easily made of pneumatic or electric valve for remote control.

(2) The difference between the three is the piston valve, the valve slightly higher working pressure.

4. Butterfly valve.

(1) has a certain adjustment function, especially for large flow adjustment, the use of temperature by the sealing material restrictions.

(2) commonly used with A-type folder on the middle of the butterfly valve, LUG-type folder on the center line butterfly valve, double flange center line butterfly valve, flange double eccentric butterfly valve, flange three eccentric butterfly valve.

5 Check valve.

(1) A check valve is a valve for preventing revers e flow of a fluid. It is generally used to prevent contamination, temperature rise or mechanical damage due to fluid back flow.

(2) commonly used swing type, lift type and ball type three. Swing diameter larger than the latter two, can be installed in the horizontal pipe or vertical pipe, installed in the vertical pipe when the fluid should flow from bottom to top, lift and ball diameter smaller, and can only be installed in the level On the pipeline.

(3) check valve can only be used to prevent sudden revers e flow but poor sealing performance, so strictly prohibited mixed materials, should also take other measures.

(4) centrifugal pump inlet for the suction state, in order to keep the liquid pump in the inlet end of the installation of the end of the valve is also a check valve. When the container is open, the bottom valve can be equipped with a strainer.

6. Diaphragm valve and the valve folder.

The two valves in use, the fluid contact with the diaphragm or hose without touching other parts of the valve body, especially for corrosive fluids or viscous liquid, suspension and so on. However, the range of use is limited by the material of the diaphragm or hose.