how useful if the last pound of propane in my 20 Lb tank?

[Anthony Hitchings]

advanced searching was not getting me an answer.

What happens to my Suburban cooktop burner flame as my propane runs out, especially as I cross the last 1 Lb mark (or maybe its the last 1/2 Lb mark?

We have never run out of propane in our 2 years of using this camper, but I would like to know if there is advance warning in behaviour/appearance of the cooktop flame.

BTW - we carry a digital scale with us on vacation, for weight control of the two occupants, and periodically also weigh the propane tank.

We alos carry a portable camp stove that uses disposable cannisters. So breakfast is assured, even if we hav eno "central heat"


FWIW - our longer term propane usage for spring and fall in the Southwest (or winter in Death Valley) is averaging 5/8" Lb/day in cooler weather (significant number of nights of 44 deg). Likely a lower usage in true summer camping.

 

[Groomporter]

At some point the flame will just start getting smaller from lack of pressure and the pressure in the tank eventually would be just too small to push out the last little bit of gas. Exactly when that happens would depend on the ambient temp.

 

[PopUpSteve]

Based on my propane campfire (connected to the tanks on the camper), the flame just starts getting low until there is not enough pressure and it goes out.

 

[jmkay1]

What happens to my Suburban cooktop burner flame as my propane runs out, especially as I cross the last 1 Lb mark (or maybe its the last 1/2 Lb mark?

. On mine there is no change up until it is just about to die out the flame may get a little lower before burning out completely a minute later. Little to no advanced warning.

 

[Sjm9911]

Never noticed it on my BBQ grill at home and I have run out of propane while cooking. So no notice. As steve said, I do notice it on the fire pit. But they use more propane.

 

[Anthony Hitchings]

Never noticed it on my BBQ grill at home and I have run out of propane while cooking. So no notice. As steve said, I do notice it on the fire pit. But they use more propane.

.. and that was my wife's recollection of how our propane grill behaved (we now have a natural gas grill hooked up to city gas).

We will therefore operate on the assumption that we can use most of the propane in the tank. The spare portable cooktop and its gas cannisters are inside the camper, so if the cooktop flame goes out we can still have a hot breakfast (and hot coffeee) without stepping outside the camper As for lack of central heat, we can always add warm layers.

Thanks for the responses

 

[PopUpSteve]

When in doubt, ask Hank!

 

[tombiasi]

The pressure in the tank will remain the same until all the liquid is gone. Then the tank pressure will start dropping as you draw from it. At some point your stove will not function properly

 

[Anthony Hitchings]

that does sound scientifically enough to be convincing (that and a little high school learning)

 

[Phil O'Regan]

Mercaptan gas is added to propane to give it a strong rotten-egg smell. I swear that when a tank is nearly empty, the mercaptan smell gets stronger even if the gas is lit and burning. I used to rent a very small house that had a propane range (stove/oven). It had two 20 lb tanks outside with a manual switch between them. I could tell from the rotten-egg smell of the pilot light when a tank was about to run dry. And no, it wasn't leaking; I could just smell it from the burning pilot light, especially if I had been out of the house for a few hours.

 

[neighbormike]

That last pound must be useful…. Otherwise they’d be selling 19lb tanks, right??

 

[tombiasi]

Mercaptan gas is added to propane to give it a strong rotten-egg smell.

Ethyl mercaptan usually burns with the propane and one wouldn't smell it. If there is no burning, as with a leak one would smell it. When the tank is running on fumes it's not unusual to smell it.

 

[tombiasi]

That last pound must be useful…. Otherwise they’d be selling 19lb tanks, right??

Last pound is as good as the first.

 

[PopUpSteve]

If this was true, 1lb bottles wouldn't work.