question for the 12 gram LAWs guys

stevebski · 06-23-2009, 05:38 PM

How did you adapt the 12 gram quick change to standard galvanized pipe threading? did you buy a specific adaptor? Links please? Anyone know what thread the standard ASA is threaded with (the male threading on the quick change) so I can hit fastenal for an adaptor?

stevebski · 06-23-2009, 06:42 PM

rumor has it that the threads on a 12 gram quick change that screw into an ASA are 1/2 - 14 NPS threads. Can anybody confirm this?

Palmers has the threading listed as .825x14 NGO which didn't even score a hit on fastenal.com. I'm in need of help!

ultranoobify · 06-23-2009, 09:22 PM

just go buy a 1/2" nipple from the hardware store

fbkmann · 06-24-2009, 08:21 AM

Yes asa threading is 1/2 pipe size. The palmers designation is the whole asa type setup machined to seal with an o ring. I was unable to screw the 12g changer directly into a galvanized fitting. Something about the taper of the thread cut. I bought a straight steel coupler at my local hardware that was 1/2 pipe and used that to adapt the 12g changer onto it. I can get a couple pics if you need.

DuckTape Dude · 06-24-2009, 02:35 PM

so you're saying that you were able to screw the 12g quick change directly into a 1/2" steel coupling? Did that mess up any threading?

stevebski · 06-24-2009, 03:31 PM

pics would be of help. The whole thread compatability thing is what's got me hung up. There's a lot of pressure in those 12 grams and I don't want to put something together with hopes and dreams that it's not going to fail later on if it's bumped wrong.

vargg · 06-28-2009, 08:45 PM

yes they have the same threads per inch(tpi). only differance is the coupler still has a taper . the 12 gram changer is strait. also the taper on the threads of the coupler varies at times . when they tap those pipes they just stop short leaving the thread tapered as to shut off on the couplers taper. ive just tefloned the threads and screwed the 12 gram changer right in. dont go nuts u may never get it off with out damaging the aluminum threads from the steal pipe. if it doesnt want to thread in very far(enuff to seal). u could tap it deeper. thats my 2 cents
as far as the size of the thread . pipe sizes are weird, the pipe is determined by the hole in the pipe, the inner diameter (i.d.) not the oouter diameter(od) like common threads

fbkmann · 06-28-2009, 10:20 PM

I'll see if i can dig up a spare coupler and get a pic. Vargg is right in the fact that most fittings are tapered to assist in sealing. I found machined steel couplers at a local hardware that were straight through and the 12g changer screwed in smoothly. I usually seal it up with black goop gasket material.

fbkmann · 06-28-2009, 10:21 PM

And as far as pressure goes we use an 8" stub of 3/4 in pipe as an expansion chamber to a 3/4in ball valve. Works great for us.

"Q" · 06-28-2009, 10:35 PM

Palmers has this option.

http://www.palmer-pursuit.com/cart/i...ducts _id=972

Here is another.

http://www.palmer-pursuit.com/cart/i...ducts _id=964

stevebski · 06-30-2009, 10:36 AM

Q, you are the man

Guys, thanks for all the help

Boom Master · 06-30-2009, 11:10 AM

The thread PITCH of an asa thread is the same but the pipe thread fittings are tapered and the ASA is a STRAIGHT thread. It can bind up and ruin some gear. You can also have a great deal of difficulty getting it to NOT LEAK.

My LAW and Cannon used a T or 4 way 1/2 NPT galvanized pipe fitting as an air intake manifold. The standardard paintball ASA threaded regulator screws directly into the fitting. But the fitting has to be MODIFIED because of the tapered thread in the fitting. Otherwise you permanently screw up the soft aluminum thread of the reg or ASA fitting. Trying to 'tighten' it to not leak is a HUGE mistake.

I use a standard 1/2" NPT tap to convert that tapered thread to a "mostly" straight thread by taping the threads in the fiting ALL the WAY up to the top of the shank of the tap. Because the tip of the tap extends 2 inches or more into the fittings, you are limited to one end or the other of the T fitting. Kind of a cut and fit operation until your asa fitting or reg will screw in finger tight without binding up and seat on the shoulder of the fitting. Now you have the thread adapted, but unfortunately it will not seal and hold air.

So again you have to modify it a bit more. You have to make sure the top of the galvanized fitting is flat, smooth, and most importanly square. They can be very rough and irregular. But a little work with a flat metal file or grinding wheel gets the job done shortly.

Then I use one of those hand drill grinders with the 45 degree stone and grind a small chamfer inside that 1/2 tread. You want it just enough you can seal an O ring between the fitting and the shoulder on your reg or Adaptor fitting. Then you have a good seal. If the O ring is too fat, it can blow out and leak under pressure. Too skinney and it won't seal. So pick your O ring and then grind to fit. Definately a cut and fit operation. Rule of thumb, if you can FEEL the O ring start to compress AND you can screw it down to the shoulder with your FINGERS, you have the right fit. Lube the ring.. Now you are set. If you did it right you can install it to work and swap regs without any problems. I snug mine down a bit just to make sure the reg doesn't back out but I really don't think I need to. That compressed O ring provides plenty of friction to prevent backing out.

stevebski · 06-30-2009, 07:39 PM

thanks dale