What temp plays havoc with gas pressure

[kevin1050]

At what temp does the pressure start to fall off? My set up is in an unheat garage and from all the talk, I will have problems with gas pressure unless I find a way to warm the tank.

What say you?

[maddog]

At what temp does the pressure start to fall off? My set up is in an unheat garage and from all the talk, I will have problems with gas pressure unless I find a way to warm the tank.

What say you?

Problems start at about 0F. At -44F propane will no longer boil and the tank produces no gas at all under pressure. Even in a heated garage a 20lb tank will fall to this temperature because of the heat that is being drawn out of it by the evaporation of propane.Propane vapor pressure

The "recommended" solution is to use a bigger tank - 100lbs. Many people who use small tanks float them in a tub of warm water. I have been using a small electric heater to keep the tank from freezing. Others have questioned the safety of this method.

See my recent thread in Gas Forges on Freezing Propane tanks for a more detailed discussion of this topic Freezing Tanks

[ThomasPowers]

Depending on where you are at the gas company may fiddle with the gas mixture to help some with temperature issues too.

[Jack Evers]

Here's a link to maddog's thread

[Jack Evers]

To put it simply, problems start when the liquid (not ambient) temps drop a ways below zero F. When that happens is complicated. How hard are you drawing vapor, how much liquid is in the tank, how long do you work at a time?, I gave an example on Maddog's thread. For the hobby blacksmith (working in an unheated garage probably qualifies) running an hour or so with tanks at least 50% full shouldn't be too much problem at reasonable temps - say 20 degrees or more.

[kevin1050]

Thanks. I posted a reply in the other thread about using a piece of homebrew equipment to keep the tank warmer. It is a heat belt used to keep your fermenting brew warmer. It wraps around and looks pretty safe.

You can get it from any homebrew shop, local or online, and costs about 25 bucks. I ordered one and will try it out. Will post results later.