Measures to prevent self suction pump intake:
(1) The installation position of the self priming pump should be as close as possible to the water surface to ensure that no air is sucked in when the water level drops.
(2) When installing the suction pipeline, the horizontal inlet pipe should be slightly tilted downwards or installed horizontally in the direction of the incoming water. The inlet pipe should not be higher than the water pump inlet at any point, otherwise the air inside the pipe cannot be completely discharged.
(3) Before installing the water inlet pipe connected by a flange, clean the surfaces where the two flanges come into contact, and add a 3-5mm thick rubber pad in the middle. The bolts should be tightened symmetrically and gradually in several steps.
(4) To prevent air leakage in the filling culvert. The tightness of the filling culvert should be appropriate. If it is too loose, the filling gland should be tightened; If the filler is damaged or ineffective, it should be replaced in a timely manner; The blockage and heating of the water seal pipe at the filling cover area will cause air leakage from the filling cover, and the water seal pipe should be cleaned.
(5) The bottom valve of the self priming water pump should have sufficient submergence depth, and the submergence depth should be 1.5 to 2 times the outer diameter of the bottom valve from the valve plane, at least not less than 0.5m. If submerged too shallow, it is easy to form vortices, which can suck in air, cause cavitation, and damage the impeller and pump casing. If it is found that the inlet water level drops rapidly during the operation of the water pump, a few wooden boards can be placed on the water surface to reduce vortices and prevent air from entering the pump casing.
(6) The vacuum degree at the suction port of the self priming pump is limited. Excessive vacuum can easily cause water vaporization inside the pump, which is not conducive to the operation of the self priming pump. So, each suction pump has its maximum allowable suction head, which is generally between 3 and 6.5 meters, and should be controlled within this range during installation.
(7) The self suction pump body is equipped with a vent plug. To facilitate venting, a faucet with the same thread size can be used instead of the vent plug. When venting, simply open the faucet.
(8) Pay attention to exhaust. Before starting the self suction pump, sufficient water should be added to eliminate the air inside the pump; Regularly open the vent plug on the pump cover to remove any accumulated air.