Pneumatic gate valve and check valve difference
Pneumatic gate valve is used as a cut-off medium, the whole flow through the full open, then the pressure of the media running the smallest loss. Pneumatic gate valves are usually suitable for applications that do not require frequent opening and closing, and to keep the shutter fully open or fully closed. Not suitable for use as a regulator or throttling. For high-speed flow of the medium, the gate in the local open conditions can cause the gate of the vibration, and vibration may damage the gate and the valve seat sealing surface, and throttling will cause the gate to withstand the erosion of the media. From the structural form, the main difference is the form of the sealing element used. According to the form of sealing elements, often the gate valve is divided into several different types, such as: wedge gate valve, parallel gate valve, parallel double gate valve, wedge double gate gate and so on. The most common form is wedge gate valve and parallel gate valve.
The check valve The role of this type of pneumatic valve is to allow only the media to flow in one direction, and to prevent the direction of flow. Usually the valve is automatically working, in a direction of the flow of fluid pressure, the valve flap open; fluid flow in the opposite direction, by the fluid pressure and the valve flap from the valve seat in the valve seat, thus cutting the flow. The check valve belongs to this type of valve, which includes a swivel check valve and a lift check valve.
The swivel check valve has a hinge mechanism, and a valve-like valve flap free to rest on the inclined seat surface. In order to ensure that the valve flap reaches the proper position of the valve seat each time, the valve flap is designed in the hinge mechanism so that the flap has sufficient swivel space and the flap is truly and fully accessible to the valve seat. The flap can be made entirely of metal, or it can be embedded in metal, leather, rubber, or synthetic coverage, depending on the performance requirements. Swing check valve in the fully open condition, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small.
The flap of the lift check valve is located on the valve seat sealing surface of the valve body. This valve in addition to the valve can be free to lift, the rest as the same as the valve, the fluid pressure so that the valve from the valve seat sealing surface lift, the media back to the valve back to the valve seat, and cut off the flow. Depending on the conditions of use, the flap may be of the all-metal structure or in the form of a rubber pad or rubber ring in the flap frame. Like the shut-off valve, the passage of the fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than the swivel check valve and the flow of the swivel check valve is limited Very few
In the production process, in order to make the media pressure, flow and other parameters in line with the requirements of the process, the need to install the adjustment mechanism to adjust the above parameters. The main working principle of the adjustment mechanism is to change the valve valve and valve and valve seat between the circulation area, to adjust the purpose of the above parameters. Belong to this type of valve collectively referred to as the control valve, which is divided by the medium itself to drive the drive called self-drive control valves such as pressure reducing valve, regulator valve, where the leading power-driven (such as electricity, compressed air and liquid Power, known as his drive control valve, such as electric control valve, pneumatic control valve and hydraulic control valve.