Progressive Cavity Pump Troubleshooting: Causes & Fixes

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Problems on this page:

Low or no flow Stator or rotor wear Run-dry damage or seal failure High starting torque or overload Joint or coupling rod failure Vibration or noise Stator swelling or chemical attack Discharge pressure too high Solids blocking the feed

Low or no flow

Hits OEE: Performance

Symptoms: Reduced or no delivery, pressure low, process starved.

Stator/rotor wear

Measure performance; replace the stator/rotor.

Air lock or starved suction

Ensure flooded suction; bleed air; check feed.

Wrong direction or speed

Verify rotation and speed for the duty.

Prevention: Wear monitoring, flooded suction, correct setup.

Stator or rotor wear

Hits OEE: Quality

Symptoms: Falling flow at the same speed, more slip, higher energy.

Abrasive product

Use correct stator material; manage solids/abrasion.

Run-dry heat damage

Prevent dry running; fit protection.

Over-pressure

Operate within pressure rating; check downstream.

Prevention: Material selection, dry-run protection, pressure control.

Run-dry damage or seal failure

Hits OEE: Availability

Symptoms: Burnt stator smell, seal leak, sudden failure.

Dry running

Fit dry-run/temperature protection; ensure feed.

Mechanical seal or packing wear

Service the seal/packing; check flush.

Misalignment or coupling wear

Align the drive; inspect the coupling and joints.

Prevention: Dry-run protection, seal upkeep, alignment.

High starting torque or overload

Hits OEE: Availability

Symptoms: The motor trips at start or the pump struggles to turn.

New stator tight on the rotor

Follow the maker's start-up advice for a new stator.

Product thicker than designed

Check product viscosity.

Stator swollen by heat or chemicals

Check the elastomer against the product and temperature.

Blocked discharge

Check discharge valves and lines.

Prevention: Motor current trended.

Joint or coupling rod failure

Hits OEE: Availability

Symptoms: Knocking, then loss of flow when the joint or rod fails.

Joint seal failed and product got in

Replace the joint seals and grease.

Overload

Check pressure and torque.

Wear at the joint pins

Replace the worn parts.

Prevention: Joints inspected at stator changes.

Vibration or noise

Hits OEE: Availability

Symptoms: The pump vibrates or knocks during running.

Worn joints

Replace the joints.

Worn stator letting the rotor knock

Replace the stator.

Loose base bolts

Tighten the base.

Air in the product

Check the suction for air.

Prevention: Vibration checked on the route.

Stator swelling or chemical attack

Hits OEE: Availability

Symptoms: The stator swells, cracks or softens.

Elastomer not compatible with the product

Choose a compatible elastomer.

Temperature above the rating

Check the temperature.

Cleaning chemicals attacking the stator

Check cleaning chemicals against the elastomer.

Prevention: Elastomer chosen per product and cleaning.

Discharge pressure too high

Hits OEE: Availability

Symptoms: Pressure builds against a closed or blocked line.

Valve closed downstream

Fit a pressure switch or relief; never run against a closed valve.

Blockage in the line

Clear the line.

Product thickening

Check the product.

Prevention: Pressure protection tested on a schedule.

Solids blocking the feed

Hits OEE: Availability

Symptoms: Flow drops or stops with thick or lumpy product and the hopper bridges.

Product bridging above the pump inlet

Use a hopper with a feed screw for thick products.

Solids larger than the pump can pass

Check the largest solids against the pump's limit.

Suction line too long or too narrow for the product

Shorten or enlarge the suction line.

Product settling in the line during stops

Flush the line when the pump stops.

Prevention: Feed conditions written down for each product.

Guidance only. Always follow lockout/tagout and your site's safe-work procedures, and verify against OEM manuals before acting.

Related equipment guides: vacuum pump · centrifugal pump · metering pump · mechanical seal · depositor · peristaltic pump · air-operated diaphragm pump

Stop the same fault coming back

Recurring progressive cavity pump stops usually trace to a cause you cannot see by hand. The partner we recommend is Fabrico: it tracks OEE and downtime live from PLCs, IoT sensors or AI cameras; where cameras are fitted, the video of a stop sits next to its machine data so the cause can be reviewed; and a technician opens the work order from the stop in the same system. Data is hosted in the AWS EU region, and Fabrico and the company behind it hold ISO/IEC 27001, ISO/IEC 20000-1 and ISO 9001.

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Methods that cut recurring stops: the six big losses · root cause analysis · preventive vs predictive maintenance · TPM · SMED & changeover