I've been following this thread for a couple weeks with interest. I ordered parts from iisports.com. Bob long on/off $7.99 (though it does have that side hole that was reported as leaking hope mine doesn't), Guage $3.99 and 20oz tank for $22.50. Ater looking at the Lowes needle valve I decided on the Detrol valve from ebay since it looked stronger.
Well yesterday I got all my parts, checked back here to set stuff up, and to my dismay found that others were having trouble with the detrol valve. I checked mine and sure enough I could blow through it
. I wasn't closing either. (as to it being new, I would say mine is new, but must be quite old stock as the brass is tarnished).
OK to the point of this post. I haven't had a chance to get the CO2 filled yet, but I did tighten up the valve. I'll use KIETHY's photo to illustrate.
On my valve there is a nut under the knob. This was screwed down a few threads that prevented the knob from fully closing. Unscrew this up against the knob first and see if your valve seals. Mine did not (blow through test)
Then I opened the valve as far as possible, and tighted the nut at the body of the valve 1/4 turn with a 10mm wrench. The valve now passes the blow through test. It may be several days before I can get the CO2 tank filled for a full pressure test but at least this improved the valve with the blow through test, and I would estimate that I still have about 1 full turn of the nut if it doesn't pass the 800psi test.
I hope this helps, and maybe one of you with the valve and a full tank can test this theroy. Also a big thanks to the original poster of this whole CO2 system.