Crash Gordon
New Member
I'm building a small boiler for an artsy-fartsy kind of project. I have a 6" length of 3" copper pipe, and I plan to cap the ends with copper "test caps". There will be a 15psi relief valve fitted to limit pressure.
Are test caps going to be sufficient to hold? I calculate about 106lbs pressure against the cap at 15psi. Test caps are much thinner than the "proper" end caps, and the cup is much shallower. So I'm concerned about both the burst strength of the cap, and the amount of solder holding the cap in place.
If I use regular caps I'm not concerned about everything holding together, but with regular caps there's hardly any pipe showing -- the caps are so deep they almost meet in the middle. And this is an artsy thing, so looks count.
I've also considered milling the regular caps down to a shallower cup; maybe 3/4" or so. These could be riveted if the cup is too shallow for solder to hold the pressure. I can make rivets easy enough out of 12ga solid wire.
Thoughts?
Are test caps going to be sufficient to hold? I calculate about 106lbs pressure against the cap at 15psi. Test caps are much thinner than the "proper" end caps, and the cup is much shallower. So I'm concerned about both the burst strength of the cap, and the amount of solder holding the cap in place.
If I use regular caps I'm not concerned about everything holding together, but with regular caps there's hardly any pipe showing -- the caps are so deep they almost meet in the middle. And this is an artsy thing, so looks count.
I've also considered milling the regular caps down to a shallower cup; maybe 3/4" or so. These could be riveted if the cup is too shallow for solder to hold the pressure. I can make rivets easy enough out of 12ga solid wire.
Thoughts?
