Ask a Question
or
Create a Poll
  1. Home /
  2. Questions /
  3. Autos & Motorcycles
  4. / Auto And Truck Fuels
  5. / Auto And Truck Fuel Information
  6. / More Auto And Truck Fuels

by Tondoteottotote on July 16th, 2005

Tondoteottotote

Question

Help answer this question below.

When filling up for fuel, how does the fuel pump "know" that your tank is getting full, makes a "clunk", and stops pumping as a result?

Share:
Other

Answers. 1 helpful answer below.

  • by anguilla on July 17th, 2005

    anguilla

    Short version: The fuel pump nozzle senses that the gasoline has reached a certain level because the tip of the nozzle actually gets touched by the rising gasoline.

    Complete version:
    Near the tip of the nozzle is a small hole, and a small pipe leads back from the hole into the handle. Suction is applied to this pipe using a venturi. A venturi is A valve which makes bubbles by drawing air into fast flowing fluid.

    When the tank is not full, air is being drawn through the hole by the vacuum, and the air flows easily. When gasoline in the tank rises high enough to block the hole, a mechanical linkage in the handle senses the change in suction and flips the nozzle off.

    Here's a way to think about it -- you've got a small pipe with suction being applied at one end and air flowing through the pipe easily. If you stick the free end of the pipe in a glass of water, much more suction is needed, so a vacuum develops in the middle of the pipe. That vacuum can be used to flip a lever that cuts off the nozzle.

    The next time you fill up your tank, look for this hole either on the inside or the outside of the tip.

    • Like
    • Report

    No comments. Post one | Permalink

Want to attach an image to your answer? Click here.

Did this answer your question? If not, then ask a new question or create a poll.

More Questions. Additional questions in this category.

You're reading When filling up for fuel, how does the fuel pump "know" that your tank is getting full, makes a "clunk", and stops pumping as a result?

Follow us on Facebook!

Related Ads

Related Questions

Professionally Researched

ANSWERBAG BUZZ

Stunts for television
How does fuel pump know full
How does your fuel pump know your out of gas
How to make fuel pump
Mechanical linkage in the handle senses

Answerbag

a Demand Media company