I was told many years ago that if an Acetylene cylinder takes a heavy blow you should run your hands over it at 15min intervals to check it isn't getting a hot spot that could lead to an explosion. I told this to a couple of guys that turned up on our site with 2 x Oxy/Acet welding units in the back of a Transit van, with no ventilation, and they said I was talking rubbish. They didn't even know the bottles have a porous core.
I was also taught this when I took a welding class in 11th grade back in 2006. And it has to do with the fact a hard impact such as could occur when struck by a forklift or similar heavy machinery, can dislodge the porous filler and allow a void where free acetylene can compress to the cylinder pressure, approximately 250 psi for a full cylinder. And we know that between 16 to 30 psi pure acetylene has a tendency to dissociate into hydrogen and carbon, creating an exothermic reaction and the cylinder can detonate within a few minutes to several hours after the incident.
And this also brings up another important safety tip. More than 1/7 of the cylinder volume per hour should never be used, since excessive flow (such as can occur when use a large heating tip) can result in acetone being sucked out though the torch. Depending on the situation a larger cylinder or multiple cylinders connected to a manifold system may be required to supply adequate flow without exceeding the 1/7 cylinder volume/hour limit.
If acetylene explodes above 15 PSI when not dissolved in acetone and is made from water and calcium carbide how is the gas pumped into the cylinder? Its pressure has to be raised in the pump and pipe en-route to the cylinder. The pressure in the pipe must be at least 260 PSI.
Where can I purchase a cylinder that will withstand 5000 gallons of liquid hydrogen please ? I know it sounds a lot but it is a tiny amount compared to what N.A.,S.A. claims to have used so should be a cinch :)
