mapp gas Q

[SE18]

Was trying to do some brazing with bernzomatic mapp/Ox setup. The mapp bottle got extremely cold. Had it on for only 5 minutes. Is this normal?

Thanks

 

[Dr.Fiero]

Map gas is a large component of green freeze refrigerant. Ditto for propane.
If its under pressure, and you reduce it's pressure, poof, you've got an a/c unit!

If it was warm out, and you had the bottle opened up a lot... It'll get cold.

As long as the valve doesn't freeze open (been there, done that!), you're good to go.

 

[Ray C]

Very normal. Any/all compressed gas will do this. As far as the inside of the bottle is concerned, mass is decreasing through an evaporative process and whenever there is evaporation, there is cooling.

Ray

 

[SE18]

Oh, thanks; when I felt the bottle I quickly disconnected everything and put the mapp bottle beside a wall where an explosion wouldn't hurt anyone; thanks