# Is my propane bottle empty? **URL:** \ **Category:** Factual Questions\ **Created:** [December 2, 2003, 8:18am UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472 "2003-12-02T08:18:47Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Blown\_Injected](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@Blown\_Injected](https://boards.straightdope.com/u/Blown_Injected)\ **Post date:** [December 2, 2003, 8:18am UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/1 "2003-12-02T08:18:47Z")
Got a gas grill this fall (I MISS MY CHARCOAL WEBBER ☹ ) and the bottle seemed to empty much sooner than I expected. Got a backup bottle - works fine, but the non working bottle seems to still have some gas in it. If I shake the bottle there is still something sloshing around in there; so what’s TSD? Thanks. ---
**Author:** ![Desmostylus](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@Desmostylus](https://boards.straightdope.com/u/Desmostylus)\ **Post date:** [December 2, 2003, 8:53am UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/2 "2003-12-02T08:53:33Z")
If it’s liquid propane in the bottle, the thing should still be working. If it’s liquid butane, that _could_ be the problem if it’s really cold where you are. Butane has a boiling point of 31[sup]o[/sup] F. Could be water in the bottle. Could also be a fault in the valve. ---
**Author:** ![FatBaldGuy](https://avatars.discourse-cdn.com/v4/letter/f/ecd19e/32.png) [@FatBaldGuy](https://boards.straightdope.com/u/FatBaldGuy)\ **Post date:** [December 2, 2003, 2:19pm UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/3 "2003-12-02T14:19:54Z")
When you get a brand new (never been filled) propane bottle, like the ones that come with a new grill, there is air inside which needs to be evacuated before filling with propane. Otherwise the bottle will not hold as much propane. ---
**Author:** ![Blown\_Injected](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@Blown\_Injected](https://boards.straightdope.com/u/Blown_Injected)\ **Post date:** [December 3, 2003, 6:17am UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/4 "2003-12-03T06:17:57Z")
The grill works with the new bottle and it is(was) not that cold so I guess some water is in the bottle - how or why there is water in the tank I do not know - it is the one that came prefilled with the grill ---
**Author:** ![DougC](https://avatars.discourse-cdn.com/v4/letter/d/7feea3/32.png) [@DougC](https://boards.straightdope.com/u/DougC)\ **Post date:** [December 3, 2003, 6:38am UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/5 "2003-12-03T06:38:08Z")
- - - (-I used to have to fill these things, like Hank Hill) There ain’t no water in the tank. At least, how water got _inside_ with ~60 Lbs PSI of propane trying to get _out_ would be an interesting theory. If there’s liquid inside, it’s propane. - The tanks come filled with dry air, and propane is heavier than air. So just leaving the tank sit level _outdoors_ and cracking the (unconnected) valve _slightly_ for a few seconds will displace any air inside out the top. The first time a new tank is filled (when it has the warning sticker over the valve), the people filling it are supposed to purge it. What they do is put a bit of propane in it, disconnect it, and crack the valve until they smell propane coming out. - If you are speaking about regular barbeque grill tanks in the US, then it is a “20-lb tank”. So called because it holds 20 lbs of liquid propane. On the collar of the tank (the shield around the top valve) there should be stamped two numbers: one will be 18-22 lbs, and the other will be… 20 greater than that. The first is the empty weight of the tank, and the second is what a full tank should weigh. Many tanks have little meters built into the valves, but these are not standardized and they tend to read 100% full and 100% empty properly, _but don’t read well between those two conditions_. So if you really need to know how much propane you got, you weigh the tank on a bathroom scale and do the math. When the tanks get filled, they are weighed, the little gauges are ignored as unreliable. ~ ---
**Author:** ![Blown\_Injected](https://avatars.discourse-cdn.com/v4/letter/b/a87d85/32.png) [@Blown\_Injected](https://boards.straightdope.com/u/Blown_Injected)\ **Post date:** [December 3, 2003, 5:29pm UTC](https://boards.straightdope.com/t/is-my-propane-bottle-empty/216472/6 "2003-12-03T17:29:37Z")
Thanks DougC. Yes, it is the 20LB tank that came with the grill in the USA - some of it MAY have even been mfg here. Problems: Thing is that it is the new type 1 style valve- the only type that the seems to be permitted these days - old type tanks will not be filled. The type 1 valve will not let the gas escape by simply turning the valve open. The numbers on the tank do not make sense to me. On the collar a number says WCG TW 17.5LB, below that, still on the collar, it reads DT-4.0 WC-47.7LB. Seems to me it is a 30LB bottle, but the Blue Rhino label says Net Weight 17lbs. (7.71 kg) Propane. There is definitely something sloshing around in the tank. My bathroom scale is crap so I do not know the actual weight. It is about 15 lbs on a junk scale. I am sure the bottle is nearly empty. I know some gas bottles (other types of gas) will work only to a certain point, but gas will still come out of the tank even if it is almost empty and below the operating pressure of the device being used.