Emulsion Resource Center

Troubleshooting

The following are offered as helpful guides to solving a pump problem.

Pump Does Not Pump

• Suction and discharge valves closed.
• Relief valve set too low or stuck open.
• Lost its prime; air leak or low tank level.
• Lines plugged.
• Belts may be loose.
• Bent or broken internal pump member.

Pump Is Noisy

• Pump is starved because possibly viscous liquid is not getting to the pump fast enough. Heat liquid to a maximum of 85° C (185° F) to reduce viscosity, increase suction pipe size or reduce suction length.
• Check alignment.
• Bent or broken internal pump member.
• Relief valve chatter, increase pressure setting.
• Securely anchor to base to reduce vibration.
• Foreign object trying to enter pump or inside pump.
• Suction line partially plugged.

Pump Delivery is Low

• Starving: see 1. Pump is starved because possibly viscous liquid is not getting to the pump fast enough. Heat liquid to a maximum of 85° C (185° F) to reduce viscosity, increase suction pipe size or reduce suction length. in 21.7.2 Pump Is Noisy.
• Air leak in suction side or through packing.
• Relief valve set to loose or stuck partially open.
• Running too slow, motor wired incorrectly.
• Partial suction line blockage.
• Pump worn out.

Pump Takes TOO Much power

• Running too fast.
• Viscous material-heat material.
• Discharge pressure too high; lessen pressure relief setting, reduce length of pipe, or increase pipe size.
• Packing gland drawn too tight.

Use of Vacuum Gauge in Suction Port

High Reading

• Suction line blocked, valve closed.
• Liquid too viscous to flow through plumbing.
• Lift too high.
• Line too small or too long.

Low Reading

• Air leak in suction line.
• End of pipe not in liquid.
• Pump is worn.
• Pump is dry; prime pump.

Erratic Reading

• Liquid coming to pump in slugs; air leak.
• Vibrating from cavitation, misalignment, damaged parts or foreign object in pump.

Use of Pressure Gauge in Discharge Port

High Reading

• High viscosity and/or small and/or long discharge line.
• Valve partially closed.
• Line partially plugged.
• Relief valve set too high.

Low Reading

• Relief valve set too low.
• Pump warm.

Erratic Reading

• Cavitation.
• Liquid coming to pump in slugs.
• Air leak in suction hose.
• Vibration