What kind of check valve is used in the sewage pump of sewage treatment plant?
3. to prevent hydraulic impact on the check valve sealing surface damage protection measures, check valve settings, to prevent the backflow of material, pump impeller to avoid the impact of the role of liquid. But as for the check valve itself, improper setting will cause a sudden impact of the disc on the valve seat by the water hammer, and damage the check valve sealing surface. Therefore, several protective measures should be taken. 1, for the pump outlet set >80mm swing check valve, horizontal installation should be adopted to weaken the valve seat back and the impact. 2, for the pump outlet check valve >=150mm diameter of the pipeline, should be placed before and after the bypass valve, to prevent the pressure before the valve rises too high, the check valve sealing surface damage. 3, the pump discharge pipeline starting and ending pressure is higher, the pipeline is not allowed to set the bypass, you can take the following measures. Set up safety valve instead of bypass valve. The action is similar to that of the bypass valve. It is located near the check valve outlet. When the water hammer causes the pressure to rise, a part of the water can be released to prevent the damage caused by the pressure rising. An air or inert gas buffer tank can be set. It is located near the check valve outlet, and when the water hammer is produced, the pressurized gas is compressed through the buffer tank to alleviate the pressure rise caused by the water hammer.
2. installation of pump outlet check valve*Swing check valves are generally mounted on horizontal pipes: for bore DN~80mm check valves, they can also be mounted on vertical or upward sloping pipes.*Straight through lift check valves shall be installed on horizontal pipes; vertical lift check valves must be mounted on vertical pipes and medium upward flow.*As the check valve is easy to damage, therefore, should be installed near the pump outlet valve, in the upper part of the check valve with a cut-off valve (general use of ball valve or gate valve), easy to overhaul.*To facilitate the relief of the check valve before disassembly, the relief valve shall be installed between the check valve and the shut-off valve.
Selection of check valve for pump outlet check valveGeneral pump station project, for the pump outlet check valve, the following principles should be observed;The outlet check valve shall be used when the diameter of the outlet pipe of the pump is smaller, that is, DN50mmThe pipeline of the pump outlet pipe diameter DN is larger than 50mm, should be used in swing check valves can be installed horizontally or vertically. Swing check valve to rotate around the shaft, the fluid resistance is generally less than the lift check valve, which applies to the larger diameter of the occasion, the installation location restrictions, usually installed in horizontal pipelines, it applies with large caliber occasions. According to the number of valves can be divided into single swing type, double valve swing and multi valve swing type of three. Single swing check valves for medium and medium duty applications. Large diameter pipeline using single swing check valve, in order to reduce the water hammer pressure, it is best to use water hammer to reduce the pressure of the slow closing check valve. Double valve swing check valves are suitable for large and medium diameter pipelines. Double check swing check valve with small structure and light weight is a fast check valve. Multi disc swing check valve is suitable for large diameter pipeline
