Positive Displacement Pump Trouble Shooting Tip: Pump Cavitation
Problem solving processing pumps and systems can be a complex task. Here’s a tip to help troubleshoot one of the most common problems in positive displacement pumps.
First, Collect Information
Before you begin troubleshooting any pump or system, the first step to correctly identify the problem is to gather as much information relating to the process as possible. Here’s a list of important information to collect:
- Double check and reconfirm original duty requirements and/or system design.
- Identify if there have been any process changes.
- Check to see what type and if the system has been undergoing routine maintenance.
- How long did the pump operate before the performance issue?
- Inspect the appearance and condition of pump internal components.
- See when the pump was last serviced.
- Listen for changes in pump noise or vibration.
Potential Causes & Corrective Action for Pump Cavitation
Pump cavitation is one of six of the most common problems that PD pumps experience. Cavitation is defined as vacuous space in the inlet port of a pump normally occupied by fluid. Excessive noise and vibration can be a result of pump cavitation. Use the below table to help identify potential problems and put a solution in place if your positive displacement pump is experiencing cavitation.
| POTENTIAL CAUSES: | CORRECTIVE ACTION |
|---|---|
| NPSHa (Net Positive Suction Head available in a system) < NPSHr (Net Positive Suction Head required from a pump) | Investigate cause – friction loss in suction – speed – sudden viscosity increase – suction head change |
| Media temperature is not as specified | Change temperature |
| Speed is too high | Reduce speed |
| Suction is restricted | Remove restriction |
| Increased viscosity | Re-calculate selection |
Rodem’s technicians have a year of experience in maintaining and repairing PD pumps, as well as a variety of other sanitary processing pumps and valves. Learn more about our preventative maintenance services as well as our timely pump repair services.
Contact a Rodem pump expert to further help identify and remedy positive displacement pump problems.