# Propane Gas question - Checking the level?

**URL:** <https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502>\
**Category:** Factual Questions\
**Created:** [December 29, 2002, 2:24pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502 "2002-12-29T14:24:03Z")\
**Posts on this page:** 3\
**Page:** 2

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**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\
**Post date:** [December 30, 2002, 1:58pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/21 "2002-12-30T13:58:59Z")

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They generally use a calculation of the degree-days of heating necessary and then fill it up to about 80% based on that.

I have it done every few months.

k2dave, look for a percentage gauge somewhere near the valve system. That should measure it up.

And I always thought it was a float…but I’ve no way of knowing if I’m right.

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**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\
**Post date:** [January 5, 2003, 3:31pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/22 "2003-01-05T15:31:57Z")

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Update- The hot water method (and just hot from the tap - not boiling) worked great, and it also worked for the kerosene tank as well so I don’t have to open it to check the level anymore. Thanks for this simple solution.

As for a gauge there is none. I confirmed this with Agway. When they do fill it they have a release valve that they open ever so often while filling. This valve is attached to a tube that extends down into the tank maybe a foot or so. When gas only excapes the tank is not full. When liquid comes out it is full. Very primative and wasteful - I was disappointed when I found out too.

BTW I estimated the tank was 1/2 full w/ the hot water, It was refilled this weekend and took 39 out of 100 gal. The level seemed to be at the 1/2 point on the tank but I think I didn’t take into account the extra room needed at the top.

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**Author:** ![brainchild876](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@brainchild876](https://boards.straightdope.com/u/brainchild876)\
**Post date:** [January 5, 2003, 3:38pm UTC](https://boards.straightdope.com/t/propane-gas-question-checking-the-level/145502/23 "2003-01-05T15:38:38Z")

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That’s exactly right. A propane tank is only at 80% capacity when it is “full”. The extra room is needed for the liquid to turn into a gas before leaving the valve. As far as the bleeder valve, a very small amount of gas is wasted while filling. I work at Ace Hardware and propane tanks on RV’s work the same way. The amount of gas released while filling is minimal once compressed into liquid. We have a 1000 gallon tank at work and AT THE MOST maybe 1 gallon is released while filling.

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