The problem of the self-priming pump not getting water, Green Ring Company cited the following major factors for your reference. I. The suction stroke is too large. (1) The degree of vacuum that can be established at the suction port of the pump is limited. For the maximum suction stroke, please refer to the manufacturer's instruction manual and install a water pump
The problem of the self-priming pump
not getting water, Green Ring
Company cited the following major factors for your reference: 1. The suction stroke is too large.
(1) The degree of vacuum that can be established at the suction port of the pump is limited. For the maximum suction range of each centrifugal pump
, please refer to the manufacturer's instruction manual. When installing the pump, do not just show the convenience and simplicity of the self-priming pump and ignore the self-priming ability of the self-priming pump.
There is air in the inlet pipe and pump body
(1) The water pump is not filled with enough water before starting. Sometimes it seems that the filled water has overflowed from the vent hole, but the air is completely discharged without turning the pump shaft, leaving a small amount of air in the water inlet pipe or pump body.
(2) The horizontal section of the water inlet pipe in contact with the pump should be applied with a descending slope of 0.5% or more in the reverse direction of the water flow, and the end connected to the inlet of the pump should be the highest, not completely horizontal. If it is tilted upward, air will remain in the water inlet pipe, which reduces the vacuum in the water pipe and the pump and affects water absorption.
(3) The packing of the pump has been worn out or the packing is too loose due to long-term use, causing a large amount of water to be ejected from the gaps between the packing and the pump shaft sleeve. As a result, external air enters the inside of the pump from these gaps. Affects water extraction. Mechanically sealed pump mechanical seal is damaged and leaking.
(4) The water inlet pipe has holes due to long-term potential underwater corrosion. The water surface continuously drops after the pump works. When these holes emerge from the water surface, air enters the private water inlet pipe from the hole.
(5) A crack appears at the bend of the water inlet pipe, and a small gap appears at the connection between the water inlet pipe and the pump, which may cause air to enter the water inlet pipe.
Third, the actual demand is too high or the suction line is too long
(1) First analyze the suction pipe is too long, because the degree of vacuum that can be established at the suction port of the pump is limited. The self-priming height of small self-priming pumps is generally 1 to 2 meters, and the self-priming height of large-caliber self-priming pumps 3 to 5 meters, if the actual required suction stroke exceeds this range, we need to install an additional foot valve.
(2) We need to minimize the use of elbow valves and elbows in the suction pipe of the pump, and shorten the distance of the inlet pipe as much as possible.
Fourth, the pump speed is too low
(1) Human factors. Due to the damage of the original motor, some users are randomly equipped with another motor to drive it. As a result, the flow is low, the head is low, or the water is not supplied.
Five, mechanical failure
(1) The mechanical failure of the pump itself. Loose fastening nut of the impeller and pump shaft or deformation and bending of the pump shaft, causing the impeller to move more, friction with the pump body directly, or bearing damage, may reduce the speed of the pump
(2) Power machine maintenance is not working. The motor is demagnetized due to burned windings, changes in winding turns, wire diameters, wiring methods during maintenance, or failure to completely eliminate factors during maintenance will also change the speed of the pump.
(3) The impeller is severely worn. Impeller blades wear out after long-term use, affecting the performance of the pump.
(4) Leakage due to damage to the mechanical seal will also result in inability to suck water.