I successfully devalved a little propane tank today, the kind they don't
want you to use any more. I bled it off for a couple of days, with the
tank set at the top of a largish sloped driveway so the gas would run down
the hill and diffuse. When it finished hissing I turned it upside down with
the valve open for a few hours. Then I took it into the shop and plumbed an
air hose to it and pressurized it to 120psi and vented it, then repeated
the air venting twice. I tried to get the valve to admit water but it plain
didn't work. I cobbled up a chain clamp setup like Ted Edward's, heated the
threaded area with a handheld propane torch until the paint barely started
to smoke, and turned the valve out easily with a large crescent wrench.
It was a lot easier than I'd thought it would be based on all the horror
stories. I filled it with hot water and a little dishwashing detergent
for a first cut at de-stinking it (I don't much like the garlicky smell
of methyl mercaptan). If anyone has any bright ideas as to how best to
get the stink out of the tank I'd like to know about it.
I'm going to make a little forge.
I cut them open with a cutting disc on a grinder after the water routine. I
leave the water in when cutting . The smell was gone from the two halves
after about a week. They make nice planters :'))
HEY, I ain't afraid of nothin but you guys are scareing me. At a certain
percentage of fuel to air it becomes self explosive. Somthing like 20 to 1.
If you wanted to purge that tank an inert gas such as nitrogen or co2 or
argon. Definitly not compressed air. Steam is a good purge and used in oil
refinery's to prep line for work. The mercaptan is a carcinogen. Get a MDS
and check it out. Those tanks are better sent to be recycled the benefit is
not worth the risk.
I am making a forge which will be a lot like Ron Reil's freon tank forge
which you can see online at http://www.reil1.net/minifor1.shtml although
he doesn't give many construction details.
I'm going to be working out of the book "Gas Burners for Forges, Furnaces
& Kilns" by Michael Porter. This book has great content but could have
used a little editing.
See Matthew Dockrey's forge construction page:
Here's another freon tank forge construction page (very similar to propane):
Don't miss Jason's forge in the dropbox:
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