acetylene pressure change from temperature change

[e30bradley]

I recently had my acetylene tank filled and I'm 95% sure that every time I get it filled it comes back at about 250 psi.. When I hooked up the regulator I noticed it was only reading 150psi. Did I get ripped off or could there possibly be that much difference from the temperature it was filled at to the temp of my garage at the time? (about 35* F)

 

[A_Pmech]

I recently had my acetylene tank filled and I'm 95% sure that every time I get it filled it comes back at about 250 psi.. When I hooked up the regulator I noticed it was only reading 150psi. Did I get ripped off or could there possibly be that much difference from the temperature it was filled at to the temp of my garage at the time? (about 35* F)

No, the delivery pressure of acetylene falls 3PSI for every 1F with 250PSI @ 70F being a baseline.

 

[Bondo]

Ayuh,... Acetylene is Wildly temperature sensitive,...

Warm it up to 70°, 'n it'll be full again,...

 

[e30bradley]

okay so if it was filled at 70* and should be what, about 250psi right? then if it was 35* in my garage ...

70-35=35 .. 35x3=105 .. okay cool. problem solved. thanks!

 

[e30bradley]

2000+ posts

 

[55bigblockcid]

A tank of acetylene is 50% acetylene 50% acetone.
The acetylene is dissolved in the acetone to keep it stable.
Safe fill pressure for acetylene tanks are 250 psi at 70 degrees f.