Assembling a CO2 regulator

[Hoppy]

I think it might be fun to report on my coming project. I have a Milwaukee regulator which I don't appreciate anymore. So, I have been shopping for a replacement, preferably a two stage regulator with a good needle valve. I could just buy one already assembled, but then I would miss out on the fun of DIY, and being a cheapskate, I hate to pay for something I can do myself.

So, I found this regulator: http://tinyurl.com/cog9d2 which looked promising to me. It appeared to be a good quality, two stage regulator, missing a gage and CGA inlet fitting. With some detective work, searching for the regulator with google, I found that it is indeed a two stage regulator, and a very good one. Ebay lets you bargain down the "buy it now" price, which I did, and got my $16 bid accepted! Ordered.

Next, I found an Ebay store selling gages that would be suitable, so I bought a 60 psi gage for $11 including shipping. Ordered.

Next, I needed a CGA320 inlet fitting, and found a few on line, the best deal being one for $10. Ordered.

Last, I struggled with Ebay for a few days looking for a good deal on a Swagelok metering valve, but to my shock, I found that all of the good ones are now priced at $150+ (I bought one several years ago for less than $50) Nothing suitable was available on Ebay. That left me having to buy a new one, something I hate to do. I reluctantly settled for the Fabco NV55, from the Fabco website, for $27 with shipping included. That is a heavy valve, with 10-32 threaded ports, meaning it can't safely be supported by the fittings in those ports, so I needed hose barbs with 10-32 threaded ends - eventually finding them at Omega.com, for $13 for a package of 10. Ordered.

This morning Fabco phoned me to verify the O-ring material to be used - they build these to order!

So, my gamble is that the regulator isn't damaged, and still works well. Assembly will be next, in about 10 days, after I receive all of the parts.

[Dalban]

BTW, any welding place will carry the CO2 inlet fitting (which is properly called a nipple). Should cost about $5-6 -- and they'll probably put it on the regulator for you if you bring it in.

If you have a regulator that has already has an Argon/Nitro/Air nipple (looks like it in your case), then the corresponding nut is the same as the CGA 320 nut, so you can just reuse what you already have.

[Hoppy]

So, I already wasted about $5-6, buying the nipple with the nut online. That makes my current error rate 20% - one bad purchasing decision out of 5. Not a good sign

[Hoppy]

This is nothing short of a miracle: I purchased the regulator on Ebay yesterday, and it arrived today! It is everything I thought it was, a professional, lab quality, two stage regulator, a monster when viewed alongside the Milwaukee regulator. Now I wonder if the weight of this thing will tip the CO2 tank over!

[TheRac25]

Hmm looks suspiciously like my matheson 3810 SS except in brass.

yes i know the solenoid is backwards in this pic

[Hoppy]

I thought it was unlikely that Air Products would be making regulators like this, but nothing I could find identified who did make it. It looks like Matheson is the one. How does yours work? It is a piston type regulator instead of a diaphragm type, so it should be very rugged and reliable, based on my experience from years ago when I worked a lot with regulators.

[tazcrash69]

Hey Hoppy, Not sure about the perspective from the camera, but that does look like a monster. I have a nice 20lb CO2 tank that looks like it would fit on nicely.

[TheRac25]

no its not piston, the product sheet says "High-purity 316 stainless steel diaphragm", seals metal to metal with teflon seats so it should last a very long time, i ve only been running it for a week with the only problem i had was solenoid backwards and only holding back about 10psi, well that and it wants to tip over my tiny 5lb tank. The threads on the front are for panel mount, delivery gauge is vac-0-60 wich is just about ideal for this purpose. still looking for an extreme resolution needle valve, have a crummy clippard on there and use the reg to dial it.


top view, im almost 100% certain looking at your pic and the one on the auction its either a matheson or matheson are also rebadges.

[Hoppy]

Today the CGA320 nipple and the pressure gage arrived by mail. A trip to the Ace Hardware store let me get an outlet hose barb with 1/4 NPT male end on it to match the regulator. So, I assembled the regulator half of the project today:
The main parts:


And, the assembly, using pipe dope as shown except on the gage, which just wouldn't tighten to the right position with dope, and had to be done with teflon tape:


Before the end of next week I will have the needle valve and hose barb fittings for it.

Total cost: For the regulator - $52.95, and for the needle valve - $40.76, for a grand total of $93.71. If the regulator works well, this will be a bargain for a two stage, high quality regulator assembly.

[TheRac25]

definatly a bargain, dual stage realy is the propper setup for this application

[Left C]

I sure am pleased that folks like dual stage regulators.

[Craigthor]

Hoppy, where did you order your 320 mount from? Trying to find one in SS or Nickel finish.

Craig

[Hoppy]

I got my CGA320 nipple from http://shop.vendio.com/supplyndemand. I was looking for low price, not appearance, so I didn't try for a plated one. This one is shorter than usual, which should be an advantage in making the regulator/tank assembly more stable, and less likely to tip over from the regulator weight.

[houstonhobby]

Let me just go ahead and reveal my ignorance. Could someone define the difference between a single and a dual stage regulator?

[epicfish]

http://www.scottecatalog.com/scottte...b?OpenDocument

http://fins.actwin.com/aquatic-plant.../msg00348.html