# Pump Cavitation (DD-413)

> Cavitation happens when local pressure in a pump falls below the liquid's vapor pressure, so vapor bubbles form. As the bubbles move into higher-pressure zones they collapse violently, sending out shock waves that cause noise, vibration, lost efficiency and pitting of gears, impellers and housings. The footage shows bubbles forming inside a transparent pump.

- Department: Tech (also Science)
- First published: 2024-12-09
- Last updated: 2024-12-09
- Permalink: https://detailenjoyer.com/case/pump-cavitation/
- Author: Marcus Easterling (DetailEnjoyer), The Detail Department

## Quick facts

- **DD-413-F01**: Pressure below vapor pressure. _(Write-up · Exhibit A (Cause))_
- **DD-413-F02**: Vapor bubbles form. _(Write-up · Exhibit B (Bubbles))_

## Write-up

When pressure in a pump drops too low, the liquid boils into bubbles. Their collapse hammers and pits metal surfaces.

1. **Cause**: Pressure below vapor pressure.
2. **Bubbles**: Vapor bubbles form.
3. **Collapse**: Bubbles implode.
4. **Damage**: Pitting and vibration.
5. **Pumps**: Gear pumps can cavitate.

## Related case files

- [Ultrasonification (DD-386)](https://detailenjoyer.com/case/ultrasonification/): I linked more cavitation
- [SonoShine (DD-387)](https://detailenjoyer.com/case/sonoshine/): I linked more cavitation

## Reel vs. record

- **Note**: None needed.

## Video: Pump Cavitation: When Pressure in a Pump Drops Too Low, the Liquid Boils Into Bubbles

- Duration: 13.6 s · Published: 2024-12-09
- File: https://detailenjoyer.com/assets/videos/DDWGLhpucXy.mp4

### Transcript

Did you know, cavitation in gear pumps occurs when the pressure in the pump drops below the vapor pressure of the fluid, causing bubbles to form in the liquid. These bubbles are carried through the pump and collapse when they encounter higher pressure zones, generating shock waves and vibrations. NOW YOU KNOW!

## Questions & answers

**Q: What causes cavitation?**  
A: Below vapor pressure. _(Source: Write-up · Exhibit A (Cause) · Wikipedia: Cavitation)_

**Q: What forms?**  
A: Boiling. _(Source: Write-up · Exhibit B (Bubbles) · Wikipedia: Cavitation)_

**Q: What happens at high pressure?**  
A: Implode. _(Source: Write-up · Exhibit C (Collapse) · Wikipedia: Cavitation)_

**Q: What damage results?**  
A: Erosion. _(Source: Write-up · Exhibit D (Damage) · Wikipedia: Cavitation)_

**Q: A symptom?**  
A: Rattling. _(Source: Write-up · Exhibit E (Pumps) · Wikipedia: Gear pump)_

## Sources

- [Wikipedia: Cavitation](https://en.wikipedia.org/wiki/Cavitation)
- [Wikipedia: Gear pump](https://en.wikipedia.org/wiki/Gear_pump)

## Cite this case file

Easterling, Marcus. "Pump Cavitation." The Detail Department (DetailEnjoyer), case file DD-413, last updated Dec 9, 2024. https://detailenjoyer.com/case/pump-cavitation/