Points for Attention of Suction Pipe and Outlet Pipe of Sewage Pump

(1) Suction pipes of sewage pumps

Each sewage pump should be equipped with a separate suction line, and strive to minimize the time to improve water conditions, reduce head loss, and reduce the possibility of impurity blocking the pipeline.

The design velocity of the suction pipe is generally 1.0-1.5m/s, and the minimum is not less than 0.7m/s, so as to avoid precipitation in the pipe. When the suction pipe is very short, the flow rate can be increased to 2.0~2.5 m/s. In order to facilitate the removal of air stored in the suction pipe, the horizontal part of the suction pipe should be slightly raised along the direction of water flow, and the pipe slope can be used 0.005. When the connection between the suction pipe and the pump needs to shrink gradually, the eccentric head and the small head should be adopted. Horn mouth should be installed at the entrance of the suction pipe, whose diameter is 1.3-1.5 times of the diameter of the suction pipe. The trumpet mouth is installed in the water accumulation pit of the catchment pool.

Valves should be installed on suction pipes of self-irrigation pumps for maintenance. If the pump is not self-irrigation, it should be started by using vacuum pump or water injector, but not by setting a bottom valve on the suction pipe, because the bottom valve is easily blocked in sewage, affecting the start of the pump, and increasing head loss and power consumption.

(2) Outlet pipes of sewage pumps

The flow rate of sewage pump outlet pipe is generally not less than 1.5m/s. When two or more pumps share one outlet pipe and only one pump works, the flow rate should not be less than 0.7m/s to avoid deposition in the pipe. When the outlet pipe of the pump is connected to the outlet main pipe (connecting pipe), it shall not be connected from the bottom of the main pipe, so as to avoid siltation in the outlet pipe of the pump when the pump stops running.

When two or more pumps share one outlet pipe, the outlet pipe of each pump should be equipped with valves and check valves between the valves and the pumps. If the pump uses a separate outlet pipe, and for free outflow, check valves are generally not required. All valves should be installed in the horizontal section as far as possible so as not to deposit dirt on the valve disc. Up.

Pipeline laying in sewage pumping station usually adopts open installation. The suction pipe is always placed on the ground. Because the pump room is deep, the outlet pipe is usually mounted on the bracket along the wall. The arrangement of pipes shall not hinder the traffic and maintenance work in pumping stations, shall not allow pipes to be installed over electrical equipment, shall not hinder the traffic and equipment hoisting and maintenance in stations, and shall pay attention to the suction pipes and outlet pipes of ground sewage pumps where they pass. The key points of suction pipes and outlet pipes of sewage pumps shall not be less than 2.0m from the bottom of pipes. Pipeline should be stable. In order to facilitate installation and disassembly, flange interface is generally used for pipelines in pumping stations. Corresponding anti-corrosion measures should be taken for pipes and valves.