Size of vertical inline pump and pipeline inlet and outlet
The water inlet of the vertical inlinepump is generally larger than the outlet, because the suction port is low pressure and the water density is small and the flow velocity is slow. In order to meet the requirements of water supply balance and ensure that the inlet has a certain pressure and prevent cavitation, it is generally large;
The flow rate of the outlet is fast and the flow rate of the same pipe diameter is large, so the water inlet to be connected is larger than the outlet. The larger the diameter of the inlet, the smaller the suction resistance, the better for the suction medium of the pump, the smaller the diameter of the outlet, and the better for the pressure maintenance of the vertical water pump outlet.
Generally, the diameter of the suction pipe is larger than the outlet pipe diameter, and the flow rate of the suction pipe varies according to the pipe diameter. When the pipe diameter is less than 250, it is 1-1.2m/s; when the pipe diameter is 250-1000, it is 1.2-1.6m/s. Technically, the maximum speed of water flow shall not exceed 2.5-3.0m/s, and the minimum speed shall not be less than 0.6m/s (to prevent sedimentation).
When installing instruments on the suction pipeline, try to avoid elbows, reducers and other parts, and avoid the influence of flow irregularities on the measurement.
The inlet pipeline of horizontal water pump shall be equipped with filtering device or trash blocking device to prevent impurities from entering the pump for circulation. And regularly remove the dirt to prevent blocking the inlet pipeline.
For the suction pipe of the parallel operation horizontal water pump, if it is connected to the common main pipe, the inlet pressure often occurs. In order to regulate the working condition of the pump, the discharge pipe should be installed with gate valve or stop valve.
In order to prevent the end suction clean water pump from turning back and being impacted by water hammer in case of sudden power failure, the discharge pipeline shall be equipped with check valve and installed behind the gate valve.
It is better to install a pressure gauge on the discharge pipeline to observe the working condition of the system and pump, and avoid elbows and valves as much as possible to avoid errors
After the pipeline is installed, it is better to conduct hydrostatic test with a pressure of 1.5 times of the design pressure, without water leakage or seepage