How to correctly check the leakage of self-priming pump pipeline pump

The self-priming pump relies on the high-speed rotation of the impeller to generate the low-pressure zone in the self-priming pump to pump the water. Therefore, the centrifugal pump must ensure that the inlet pipe does not leak, that is, the external air cannot enter the inlet pipe. Otherwise, it will not only affect the efficiency of the pump, but also cause serious vibration and noise during the operation of the pump.

During work, if there is insufficient or no water from the water pump, the first thing to consider is whether the water inlet pipe is trapped in the trachoma, cracks, or joints, and observe it to find out the air intake. Some of the flaws are very subtle. It is difficult to find out by looking directly at the naked eye. It is often time-consuming but inconclusive. Several easy-to-use methods for checking the air leakage from the inlet piping of the pump are introduced.

(1) Duck hair method: Using a duck down, close to the suspected air intake when the pump is running, observe the floating condition of duck hair. Similarly, lighted cigarettes can be used as such. Help find by the direction of the drift of the duck hair and smoke.

(2) Engine oil method: For the air intake points that are difficult to find, apply a little oil at a certain approximate air intake location. The engine oil is quickly sucked away at the intake.

2. Measures for Preventing Self-priming Centrifugal Pump Air Intake (1) Self-priming pump should be installed as close to the water surface as possible to ensure that air does not inhale when the water level drops.

(2) When installing the suction pipe, the horizontal pipe should be installed with a slight tilt or horizontally in the direction of the incoming water. The water inlet pipe should not be higher than the inlet of the pump at any point, otherwise the air in the pipe will not be exhausted.

(3) Prevent fillers from leaking. The tightness of the packing culvert should be suitable. If it is too loose, the packing gland should be tightened. If the packing is damaged or fails, it should be replaced in time. The water sealing tube at the filling area should be blocked and heated, which will cause the packing to cover the air leakage. The water sealing tube should be cleaned. .

(4) Before installing the water inlet pipe connected with the flange, clean the plane in contact with the two flanges, add a 3~5mm thick pad in the middle, and tighten the bolt symmetrically and several times step by step. .

(5) Sufficient submergence depth of the bottom valve of the suction pump shall be sufficient. From the plane of the valve, the submergence depth shall be equal to 1.5 to 2 times the outside diameter of the bottom valve, and shall not be less than 0.5 m at least. If the submergence is too shallow, vortices will form easily, which will inhale air, cause cavitation and damage the impeller and pump casing. If you find that the water level drops quickly when the pump is running, you can put a few pieces of wood on the water to reduce the vortex and prevent air from entering the pump casing.

(6) A self-priming pump body is provided with a bleeder screw plug. To facilitate deflation, a bleed screw plug can be replaced with a tap having the same thread size, and the water tap can be opened when deflated.

(7) The degree of vacuum at the suction port of the self-priming pump is limited. If the degree of vacuum is too large, it tends to vaporize the water in the pump and it is not good for the self-priming pump. Therefore, each suction pump has its maximum allowable suction range, generally between 3 ~ 8.5m, and should be controlled in this range during installation.

(8) Pay attention to exhaust. Before starting the self-priming pump, sufficient water should be added to eliminate the air in the self-priming pump. At ordinary times, the bleed plug on the pump cover should be opened regularly to eliminate the air accumulated in the pump.