Precautions And Supporting Parts For Starting Self-priming Pump

May 09, 2025

A self-priming pump has a certain self-priming ability, which enables the water pump to easily start and maintain normal operation while sucking in water. Most of the self-priming pumps produced today are self-priming centrifugal pumps. Due to their different self-priming methods, self-priming pumps can be divided into various structural forms such as external mixed self-priming pumps, internal mixed self-priming pumps, and vacuum pumps with driving force provided by the pump itself.
The key components include: pump body, pump cover, impeller, shaft, rolling bearings, etc. The pump body is equipped with a vortex shaped flow channel, and there is a large capacity of gas and water separation chamber around the surface of the flow channel. The lower part of the pump body is cast with a seat angle for fixing the pump. The suction inlet of the self-priming pump is located above the impeller. After each shutdown, some water can be retained in the pump for the next start-up. Before starting again, the pump should be manually filled with self-priming tap water to submerge the majority of the impeller in the water.

After the pump is started, the water in the impeller flows into the edge of the impeller under the actual effect of centripetal force, and mixes with the steam body at the edge of the impeller to produce a circle of foam plastic strip like air-water compound. The foam plastic belt enables the gas water compound to enter the gas water separation chamber through the dispersion tube under the actual scraping effect of the tongue separator. At this point, due to the sudden increase in the total area of blanching, the water flow rate cleverly decreases, and the density of the vapor is low. The vapor escapes from the water and is discharged through the pump outlet. The water has a high density and falls into the bottom of the air-water separation chamber, returning to the edge of the impeller through the axial return hole and mixing with the vapor again.

Following the continuous circulation system of the process, the vacuum value in the suction pipe continues to increase, and the transported water continues to rise along the suction pipe. When the pump is completely filled with water, it enters all normal operating conditions and undergoes self-priming process. The inlet and outlet of the pump body can be connected with rubber hoses or flange coils. When matching rubber hoses, the inlet hose joint seat is equipped with a check valve to prevent the backflow of shutdown liquid. The pump body is equipped with a closed test single suction impeller in the vortex passage, and the pump cover has a sealed chamber. The rolling bearing body is fitted with salt free grease to smooth the rolling bearings. A V-belt pulley or coupling is developed at the rear end of the pump shaft, and the pump is driven by an electric motor or gas turbine.