Return an oral! Centrifugal pump outlet pressure reduces the reason -

( 1) Motor reverse

because of the connection, the turning of the motor would be contrary to centrifugal pump's actual need to. Usually, the startup should observe the steering pump. If turned to the contrary, any two wires on the motor terminal should be changed.

( 2) Working point to the large capacity low head

in general, the performance of the centrifugal pump with continuous downward curve, flow gradually increased with the reduce of lift. In the process of operation, for some reason, the back pressure of the pump is reduced, the working point of the pump with gear curve move passively to the low lift point flow, this will lead to lower head. In fact, this is caused by the change of the external factors such as equipment, no special relationship with pump itself. At this time, as long as the back pressure of the pump increases, such as closing the outlet valve, etc. Problems can be solved.

( 3) Slow down

the important factors influencing the centrifugal pump pump head is the outer diameter of the impeller and pump speed. In the case of other conditions unchanged, the direct ratio of secondary pump head and speed. You can see that the speed of pump head have a big impact. Sometimes, if the pump speed due to some external factors, and the pump head will reduce accordingly. At this point, check the pump speed. If the speed is not enough, should check the reason and reasonable solution.

( 4) At the entrance of cavitation

if centrifugal water pump suction pressure is too low and lower than the saturated vapor pressure of pumping medium, will form the cavitation. At this point, check the inlet piping system is blocked, or whether the inlet valve opening is too small, or ascending suction tank liquid level.

( 5) Internal spill

when the rotation of the centrifugal pump parts and still part of the gap between the range of design, internal leakage happens, this is reflected in the pump discharge pressure drop, such as the clearance between the impeller mouth ring and multistage gap between the level of the pump. At this point, should undertake the corresponding disassembly and inspection, to repair or replace parts lead to excessive clearance.

( 6) Impeller channel blockage

if part of the impeller flow channel plugging, the work of the impeller will be affected, outlet pressure drop. Therefore, it is necessary to remove the pump for inspection and removal. In order to prevent this problem from happening again, if necessary, can add the filter in front of the centrifugal pump suction device.