"DaveC" wrote in message
news.net...
I've got an old 20 gal (?) compressor tank in which I want to install a
drain. I'm guessing it to be 1/4-inch (6.3 mm?) thick steel. Tank is rated
to
125 psi.

Can I drill and tap this for 1/4 or 3/8-inch pipe? Or should i get a
"plug"
welded to it that I can drill & tap?

Are there rules to follow for such stuff? Is there a better n.g. to ask
this
question in?

Thanks,
--
Please, no "Go Google this" replies. I wouldn't
ask a question here if I hadn't done that already.

DaveC

Dave

Since this is a drain, and you are concerned about the integrity, maybe
you'd be less concerned with a 1/8th pipe valve, or petcock.
But, if the tank pressure never gets higher than 125 psi, the force on 1/2
inch diameter area is only about 25 pounds. Besides, the valve is on the
bottom so there is minimal probability of any failure injuring anyone.

Jerry