Acetylne Cylinders

Not True! I worked as a service tech at a welding shop and acetylene cylinders get drawn down to 0 PSI. They will not stay that way for long though. Being the acetylene is absorbed into either a chalk like material or a cork material its not possible to completely empty a cylinder.

I have my own acetylene tanks and I run them until the torch wont run any more.

Thanks for your information.

.....my acetylene cylinder never gets below what I have it regulated at, Not enough psi. change it out.

The cylinders are usually filled with a porous material and then the acetylene dissolves in the acetone, acetone is usually pumped into the system prior to filling the cylinder with the gas (up to an appropriate weight). Acetylene by itself, over a certain pressure is definitely a problem. At the fill plant I worked at, we didn't run the carbide reactor over 15 psig.

I've never heard of people blowing up their cylinders by losing all the acetone, usually they knock the valve stem off or leave the cylinder open and it leaks to an ignition source and good bye world.

I have never heard of a minimum pressure of 3,5 barg for acetylene cylinders. The acetone will not be discharged at pressures lower than this. The acetone can be discharged if the bottle is not vertical and this would occur at any pressure.

I agree with the second statement that it is dangerous to have an acetylene cylinder without acetone as there is then the danger of having "free" gas which could violently decompose leading to an explosion.

Under normal circumstances you would never run a cylinder to zero as your flame would become unstable before that point. Much more dangerous is to use an acetylene cylinder with a too big nozzle and to break the 1/7 rule, or to use the bottle lying on its side, or to set the regulator to a pressure higher than 15 psi, etc etc.