The Correct Installation Method For The Suction And Discharge Pipelines Of The Pump

Aug 30, 2024

1) The configuration of the suction and discharge pipelines of the pump should comply with the following regulations:
① All pipelines connected to the pump should have independent and sturdy supports to reduce pipeline vibration and prevent the weight of the pipeline from pressing on the pump.
② The diameter of the suction and discharge pipelines should not be smaller than the inlet and outlet diameters of the pump.
③ The suction pipeline should be short and the number of bends should be reduced.
④ When using a variable diameter pipe, the length of the variable diameter pipe should not be less than 5-7 times the difference in pipe diameter.
⑤ There should be no place for gas to accumulate in the suction pipeline. When the installation position of the pump is higher than the suction liquid level, no part of the suction pipeline should be higher than the inlet of the pump. The horizontal straight pipe section should have a slope (higher at the pump inlet) and should not be less than 5/1000-20/1000.
⑥ Expansion joints should be installed in high-temperature pipelines to prevent the force generated by thermal expansion from fully acting on the pump.
⑦ Valves required for process flow and maintenance should be set as needed.
⑧ When two or more pumps are connected in parallel, a check valve should be installed at the outlet of each pump.
2) The pipeline configuration of centrifugal pumps should also meet the following requirements:
① Inhalation pipeline:
a. The length of the straight pipe section before the pump inlet should not be less than three times the inlet diameter D.
b. When the installation position of the pump is higher than the suction liquid level and the inlet diameter of the pump is less than 350mm, a bottom valve should be installed. When the inlet diameter is greater than or equal to 350mm, a vacuum water intake device should be installed.
c. The depth a of the suction nozzle submerged in the water surface should not be less than 1.5-2 times the inlet diameter D, and should not be less than 500mm. The distance b between the suction nozzle and the bottom of the pool should not be less than 1-1.5 times the inlet diameter D, and should not be less than 500mm. The distance c between the center of the suction nozzle and the pool wall should not be less than 1.25-1.5 times the inlet diameter D; The center distance d between the suction ports of adjacent pumps should not be less than 2.5-3 times the inlet diameter D.
d. When installing a filter screen in the suction pipeline, the total flow surface area of the filter screen should not be less than 2-3 times the area of the suction pipe mouth.
e. To prevent clogging of the filter screen, a trash net or trash rack can be added around the inlet of the suction tank or the suction pipe.
f. Mud pumps, ash pumps, and sand pumps should operate under backflow conditions. The pouring height should be 2-3mm, and the suction pipe should be inclined at 30 °.
② Pump discharge pipeline:
a. Gate valves should be installed, and their inner diameter should not be smaller than the inner diameter of the pipe. Vortex pumps should also be equipped with safety valves.
b. When the head is greater than 20m, a check valve should be installed.
③ The inlet and outlet pipelines of the impurity pump should not make sharp turns to prevent blockage.
3) The pipeline configuration of axial flow pumps and mixed flow pumps should also meet the following requirements:
① The distance between the center of the water pump inlet and the pool wall should be 0.1-1.25 times the diameter D of the suction horn pipe, and the distance between the suction pipe and the pool bottom should be 0.7-0.8 times the diameter D of the suction horn pipe. The distance between the centers of the suction inlets of adjacent pumps should not be less than 2-2.5 times the diameter D of the suction horn pipe.
② The discharge pipeline should be equipped with a check valve (or flap valve), and a diffusion pipe should be installed between the pump discharge outlet and the check valve. The length of the diffusion pipe should not be less than 5-7 times the difference in pipe diameter.
③ The piping of the vortex shell mixed flow pump should be executed according to the centrifugal pump.
4) The pipeline configuration of mobile reciprocating pumps and steam reciprocating pumps should also meet the following requirements:
① The discharge pipeline should be equipped with a safety valve.
② It is advisable to install a suction air chamber at the inlet of the pump to improve its suction performance. A discharge air chamber can be installed at the outlet of the pump as needed to stabilize the flow rate and discharge pressure.
5) The pipeline configuration of the metering pump should also meet the following requirements:
① The pump should work under reverse flow conditions to ensure that it can be driven at any time and to ensure measurement accuracy.
② T-shaped piping should not be used for the discharge pipeline to prevent the measurement accuracy from being reduced due to siphon effect after the pump is stopped. When T-shaped piping is needed, a vacuum breaking valve should be installed at the high point of the pipe.