Problem

Cause

Solution

Pump does not start

Insufficient Motor Power / Performance

Check Motor Rating, Power, that motor is running operationally sound independently of the pump, Winding resistance. Repair/Replace if necessary

Insufficient output from Frequency Converter

Check Frequency converter matches motor

Pump Blockage

Check Voltage and current draw. Pump Start occurs at 10Hz

Pump Blockage

Check if pump suction or discharge is blocked

Reduced Flow or Pressure

Valves on discharge and/ or suction may be closed fully or partially

Open Valves fully

Pump Hose Compression too little

Check number of shims fitted on rollers is correct for pump model

Hose Rupture / Leakage

Replace Hose

Partial Blockage

Clear Suction and Delivery lines

Insufficient Inlet Pressure

Increase level of fluid in the suction tank, replace pump or reduce pump speed

Inlet Pipework too Small

Increase Suction Pipe Diameter

Suction Line too Long

Ensure Suction line is as short as Possible

Viscosity of Fluid

Check it is in line with the original specification.

Viscosity may change with temperature.

Suction of Air

Ensure Connections are airtight

Pulsating Suction Line

Ensure all connections are tight. Use pulsation dampeners to reduce pulsations by up to 98%. Check Application

High Pump Temperature

Hose not lubricated

Lubricate Pump Hose

Product Temperature High

Reduce Fluid Temperature

Poor Suction Conditions or

Insufficient Suction

Check Suction Line for

Blockages

Pump Speed too High

Reduce Pump Speed

Vibration on Pump & Pipework

Connecting Pipework not fastened correctly

Ensure pipework is connected with accessories such as brackets where required

Pump speed too high

Reduce pump speed

Insufficient pipe bore

Increase bore of the pipe

Pump loose on baseplate

Tighten baseplate

Pulsation dampeners insufficient or missing

Install pulsation dampeners on suction & discharge

Short Hose Life

Chemical Attack

Check Hose Chemical Compatibility with liquid pumped, any cleaning agents used and lubricant

High Pump Speed

Reduce Pump Speed

High Temperature

Reduce fluid Temperature

High Operating Pressure

Reduce Operating Pressure

Cavitation

Check Suction Conditions including bore of the pipe, tank size, the viscosity of fluid with pump capacity.

Elevated Temperature

Check Rollers Shaft Mounting

Unsuitable Lubricant

Only use Lubricant from North Ridge Pumps

Insufficient Grease

Top Up Lubricant

Pump Hose Pulled into Housing

High Inlet Pressure >3 Bar

Reduce inlet Pressure

Pump Hose contains Deposits

Clean or Replace Pump Hose

Holder (press flange) not Tight

Re-tighten Press Flange and Holder

Insufficient Grease

Top Up Lubricant