The installation and maintenance of the gate valve should pay attention to the following matters: the handwheel, the handle and the transmission mechanism are not allowed to be used for lifting, and collision is strictly prohibited.
The double gate gate valve should be installed vertically (ie the stem is in the vertical position and the handwheel is on the top). The gate valve with the bypass valve should open the bypass valve before opening (to balance the differential pressure between the inlet and outlet and reduce the opening force). The gate valve with transmission mechanism is installed according to the product manual. If the valve is used frequently, it should be lubricated at least once a month. The gate valve is used as the cut-off medium. When it is fully open, the whole flow is straight through. At this time, the pressure loss of the medium operation is small. Gate valves are generally suitable for applications that do not require frequent opening and closing, but also keep the shutter fully open or fully closed. Not suitable for use as an adjustment or throttling. For high-speed flowing media, the gate can cause vibration of the gate under partial opening conditions, and the vibration may damage the sealing surface of the gate and the valve seat, and the throttling will cause the ram to be eroded by the medium. The main difference in terms of structural form is the form of the sealing element used. Depending on the form of the sealing element, the gate valves are often divided into several different types, such as wedge gate valves, parallel gate valves, parallel double gate gate valves, wedge double gate gates, and the like. Commonly used forms of zui are wedge gate valves and parallel gate valves. The function of this type of valve is to only allow the medium to flow in one direction and prevent the direction from flowing. Usually, the valve is automatically operated, and the valve flap is opened by the fluid pressure flowing in one direction; when the fluid flows in the opposite direction, the fluid pressure and the self-reclosing valve flap of the valve disc act on the valve seat to cut off the flow. Among them, the check valve belongs to this type of valve, which includes a swing check valve and a lift check valve. The swing check valve has a hinge mechanism and a door-like flap that rests freely against the inclined seat surface. In order to ensure that the valve flap can reach the proper position of the valve seat surface each time, the valve flap is designed in the hinge mechanism, so that the valve flap has enough swinging space and the valve flap is truly and comprehensively in contact with the valve seat. The discs can all be made of metal, or they can be inlaid with leather, rubber, or synthetic coverings depending on the performance requirements. In the fully open condition of the swing check valve, the fluid pressure is almost unimpeded, so the pressure drop across the valve is relatively small. The valve flap of the lift check valve is located on the valve seat sealing surface of the valve body. In addition to the valve flap being free to lift and lower, the valve is like a shut-off valve. The fluid pressure causes the valve flap to lift from the valve seat sealing surface. The return of the medium causes the valve flap to fall back to the valve seat and shut off the flow. Depending on the conditions of use, the flap may be of an all-metal construction or may be in the form of a rubber or rubber ring on the valve disc holder. Like the shut-off valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is limited. Very few. In the production process, in order to make the pressure, flow and other parameters of the medium meet the requirements of the process flow, it is necessary to install an adjustment mechanism to adjust the above parameters. The main working principle of the adjustment mechanism is to adjust the flow area between the valve flap and the valve flap and the valve seat to achieve the purpose of adjusting the above parameters. These valves are collectively referred to as control valves, which are divided into self-driven control valves such as pressure reducing valves and pressure regulators that are driven by the medium itself. Where ling is first driven by power (such as electricity, compressed air and Hydraulic power is called his drive control valve, such as electric control valve, pneumatic control valve and hydraulic control valve.