Why do heads decreases and discharges increase in a Water Pump Copied by TDRFORCE Water Pump Factory or Manufacturer?

Why do heads decreases and discharges increase in a Water Pump Copied by TDRFORCE Water Pump Factory or Manufacturer

Published on https://tdrpump.com

About the Publisher: TDRFORCE Factory or Manufacturer direct Online Sale Drinking Water Pump, RV Water Pump, Pressure Booster Pump, Sump Pump, Hot Water Pump,Submersible Pump, Liquid Transfer Pump, Garden Pump, Irrigation Pump, Pond Pump, Customized Pump etc

How to solve the Common faults and treatment of Water Pumps Writen by TDRFORCE Factory

Description: Why do heads decreases and discharges increase in a Water Pump Copied by TDRFORCE Water Pump Factory or Manufacturer? Let's follow the guide from TDRFORCE Pump Factory or Manufacturer.

TDRFORCE PUMP Factory|Manufacturer

Why do heads decreases and discharges increase in a Water Pump ? The Tech Answer From TDRFORCE Water Pump Factroy|Manufacturer?

Impeller flow channel blocked


If part of the flow passage of the impeller is blocked . it will affect the work of the impeller and cause the outlet pressure to drop.Therefore,it is necessary to disassemble the pump to check and remove foreign objects .To prevent this problem from recurring.if necessary,a filter device can be installed before the pump inlet


Internal leakage


When the gap between the rotating part and the static part of the pump exceeds the design range,it will cause internal leakage,which is reflected in the drop in the discharge pressure of the pump. such as the gap between the impeller orifice and the interstage gap of the multi-stage pump.At this time the corresponding disassembly and inspection should be carried out and the parts that cause the excessive clearance should be repaired or replaced

Cavitation at the entrance


If the suction pressure of the pump is too low,lower than the saturated vapor pressure of the pumped medium,cavitation will form.At this time, check whether the inlet piping system is blocked or the inlet valve opening is too small, or increase the liquid level of the suction pool.

Speed reduction


The important factors that affect the pump head are the outer diameter of the impeller and the speed of the pump. Under other conditions unchanged, the head of the pump is proportional to the square of the speed.It can be seen that the impact of speed on the head is very large. sometimes because Some external reasons reduce the speed of the pump, which will reduce the pump head accordingly.At this time,check the speed of the pump.If the speed is indeed not enough. check the cause and solve it reasonable.


Working condition point shifts to large flow and low head


Under normal circumstances. centrifucal pumps have a continuous downward performance curve and the flow rate gradually increases as the head decreases in the process operation, due to some reasons,the pump back pressure is reduced,and the working point of the pump passively shifts to the low-lift and large-flow point along the device curve which will cause the head to decrease. In fact.this is due to external factors such as the device.The result of the change has nothing to do with the pump itself.At this time, the problem can be solved by increasing the back pressure of the pump. such as closing the outlet valve a little


Motor reverse


Due to the wiring reasons. the steering of the motor will be opposite to the actual required steering of the pump. Generally the steering of the pump should be observed first when starting. If the steering is reversed,any two wires on the terminal of the motor should be exchanged.

In TDRFORCE Opion, The followings are What are the reasons for the decrease of pump head?

The impeller passage is blocked

If the impeller part of the flow channel is blocked, it will affect the work of the impeller, resulting in a drop in outlet pressure.Therefore, it is necessary to remove the pump for inspection and removal of foreign bodies.In order to prevent the problem from appearing again, if necessary, a filter device can be added before the pump inlet.

Internal leakage occurs

When the clearance between the rotating part and the stationary part of the pump exceeds the design range, it will lead to internal leakage, which is reflected in the decrease of the discharge pressure of the pump, such as the clearance between the impeller mouth ring and the inter-stage clearance of the multi-stage pump.At this time, the corresponding dismantling should be carried out to repair or replace the parts that cause excessive clearance.

Cavitation at the inlet

If the pump inlet pressure is too low, lower than the saturated vapor pressure of the pumping medium, cavitation will be formed.At this time should check whether the inlet pipeline system is blocked or whether the opening of the inlet valve is too small, or improve the liquid level height of the suction tank.

Speed to reduce

The important factor affecting the pump head is the impeller diameter and the pump speed, in other conditions unchanged, the pump head and the speed of the quadratic proportional relationship, visible speed on the head is very large, sometimes because of some external reason to reduce the speed of the pump, the corresponding decrease in the head of the pump.At this time should check the speed of the pump, if the speed is not enough, should check the reason, reasonable solution.

The working point deviates to large flow and low head

In general, centrifugal pumps have a continuous downward performance curve, flow with the decrease of the head gradually increased.In the process of operation, due to some reason to reduce the pump back pressure, the working point of the pump passively offset with the device curve to the low head and large flow point, which will cause the head reduction, in fact, this is caused by external factors such as the change of the device, and the pump itself has no special relationship.At this time, as long as the pump back pressure is increased, such as closing the outlet valve can solve the problem.

Motor reversal

Because of wiring causes the motor to turn opposite to the actual requirements of the pump, so generally start to observe the steering of the pump, if the steering is reversed, should be any two wires on the motor terminal can be exchanged..

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.

Contact form

Solution For Pump Works but NOT Pumping Water

How to solve malfunction: Pump Working but NOT Pumping Water in Varied Model of Bottled Water Dispensing System(also called Bottled Water Dispener System or Bottled Water System or Drinking Water Dispener or Drinking Water Dispensing System). This Video Original from TDRFORCE Brand Factory or Manufacturer on Web https://tdrpump.com, which has 25 years' manufacturing Bottled Water Dispensing System since 2000.