Copper pipe size

[dave1]

I have a problem finding a short piece of tubing/pipe/whatever to fit inside type L copper tube. I am building a 1/2" piston valve for relieving a 2" (1.5" Ported) main piston. It would have to be something that I can solder in place. I have turned a piston from oak and faced it with gasket rubber. The only stumbling block is the piston seat which must protrude halfway into a 1/2" copper tee. I've tried various plastic arrangements, but they all melt when I do final soldered assembly. Has anyone ever found the right size for this application?

[cdheller]

acr copper in 1/2 in has a o.d of 1/2 in .50
1/2 m,l,and k have i.d of .569 ,.545 ,and .528 .
If you heat copper red hot it becomes soft enough to work.
as in swaging from .500 to the i.d. of the k,l,or m.

hope this helps

[dave1]

Thanks. I've found the perfect tube to fit inside that L type copper. It's a short 1/4"NPT brass nipple. I was able to chuck it up in a 1/2" chuck and minimally turn/file it down to make a perfect fit. After I soldered it with just the right protrusion, I bored it out bigger to handle more exhaust. It works really great. I fill the whole setup through the blowgun trigger. I have a male QC on the blowgun and just feed it backwards. It's very quick. Dry fires are LOUD even at 50lbs.