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Pump Cavitation

Short answer: 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.

VideoWrite-up2 sources

What should you know about Pump Cavitation?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Pressure below vapor pressure.

    DD-413-F01 · Write-up · Exhibit A (Cause)
  2. Vapor bubbles form.

    DD-413-F02 · Write-up · Exhibit B (Bubbles)

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

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!

Burned-in captions, read frame by frame (see transcript.md) · 13.6s Reel ·

Video coming soonPump Cavitation · Instagram Reel
Pump Cavitation: When Pressure in a Pump Drops Too Low, the Liquid Boils Into Bubbles Instagram Reel · · 13.6s

The write-up

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

  1. Exhibit A

    Cause

    Pressure below vapor pressure.

  2. Exhibit B

    Bubbles

    Vapor bubbles form.

  3. Exhibit C

    Collapse

    Bubbles implode.

  4. Exhibit D

    Damage

    Pitting and vibration.

  5. Exhibit E

    Pumps

    Gear pumps can cavitate.

Questions people ask about Pump Cavitation

What causes cavitation?

Below vapor pressure.

Source: Write-up · Exhibit A (Cause) · Wikipedia: Cavitation

What forms?

Boiling.

Source: Write-up · Exhibit B (Bubbles) · Wikipedia: Cavitation

What happens at high pressure?

Implode.

Source: Write-up · Exhibit C (Collapse) · Wikipedia: Cavitation

What damage results?

Erosion.

Source: Write-up · Exhibit D (Damage) · Wikipedia: Cavitation

A symptom?

Rattling.

Source: Write-up · Exhibit E (Pumps) · Wikipedia: Gear pump

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. What causes cavitation?

    1. Low pressure
    2. High heat only
    3. Magnetism
    4. Light
    Show the answer

    Answer: A. Low pressure Below vapor pressure. Source: Write-up · Exhibit A (Cause) · Wikipedia: Cavitation

  2. What forms?

    1. Vapor bubbles
    2. Ice
    3. Sand
    4. Oil
    Show the answer

    Answer: A. Vapor bubbles Boiling. Source: Write-up · Exhibit B (Bubbles) · Wikipedia: Cavitation

  3. What happens at high pressure?

    1. Bubbles collapse
    2. They grow
    3. They freeze
    4. Nothing
    Show the answer

    Answer: A. Bubbles collapse Implode. Source: Write-up · Exhibit C (Collapse) · Wikipedia: Cavitation

  4. What damage results?

    1. Pitting
    2. Rust only
    3. Paint loss
    4. None
    Show the answer

    Answer: A. Pitting Erosion. Source: Write-up · Exhibit D (Damage) · Wikipedia: Cavitation

  5. A symptom?

    1. Noise and vibration
    2. Silence
    3. Cooling
    4. Glow
    Show the answer

    Answer: A. Noise and vibration Rattling. Source: Write-up · Exhibit E (Pumps) · Wikipedia: 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/

Permalink: https://detailenjoyer.com/case/pump-cavitation/ · Last updated

Markdown version

Cite a single fact by its ID, for example DD-413-F01 → https://detailenjoyer.com/case/pump-cavitation/#DD-413-F01