Hello TPT. I posted this on SFBAAPS a month or so ago and thought it might be useful to someone here. If you see any errors please let me know. I'm always open to constructive criticism.
I had been thinking of replacing an old single stage JBJ regulator bought from Tom Barr or Dave Gomberg many years ago, for quite awhile. It's had a few end of tank dumps that have killed some fish over the last 13 years but, for the most part, it worked well. The loss of livestock bugged me however, so I promised myself I would convert to all dual stage regs as it became affordable to do so.
I bought my first used SS dual stage to replace the JBJ awhile back for $320ish and the JBJ went onto the nano tank with a paintball canister. A few weeks ago I came across a nice used Matheson reg on fleabay for $40 so I decided to jump in and build my first reg from parts.
While I've known the basics on how to do so for awhile from a lot of online lurking, determining which parts to use, sourcing parts, assembling, etc was all new. Especially sourcing the parts. So I thought I'd post some information to help out those wanting to do the same.
First things first...
I don't intend to get into why you should or shouldn't do this as it's been discussed heavily in other places. The cost is dependent upon the components you decide to use. Solenoid, metering valve, and even pipe fittings vary quite a bit in price. Material choice makes a big difference in cost. You can save a bunch of money by going with all brass components vs stainless steel. Nickel or SS plated brass is middle of the road but you won't find all of your components in that finish as far as I could find.
Swagelok is a great place to start for pretty much any fitting you need. The stainless steel parts are expensive, top of the line fittings that are designed to handle much more abuse than we will ever put them through. Brass and a few other materials are also available at Swagelok. You can find some new/used parts in SS on ebay to save some cash but unless you are patient, probably not all you need in a short period of time. I decided to use new Swagelok stainless steel fittings for my build for both corrosion resistance and looks. Mostly looks 😁
List of vendors, parts, and tools:
Regulator from ebay -
Matheson MREG-5137-XX Dual Stage Regulator 81H-580 3000 PSI
This reg came with only one broken gauge and an Oxygen tank inlet nipple. Gauges and nipple needed replaced and the output valve removed. Any regulator with a 50psi to 150psi output range is good for our needs. Anything less than 50psi may not provide enough pressure for some of the diffusers that we use. Anything over 200psi low pressure gauge/rating should be skipped because it won't provide enough resolution sub 50psi.
CGA-320 Nut & 2.5" Nipple - Chrome Plated (length depends upon what size gauges your reg has. 2.5" gauges require more clearance)
****The ports on the reg are 1/4" NPT. I reduced it at the elbow to 1/8" NPT****
Part No. SS-4-RSE-2 Reducing Street Elbow, 1/4 in. Female NPT x 1/8 in. Male NPT
Part No. SS-2-MT 3 way male tee 1/8" NPT
**** I chose to use a 3 way tee with one end capped instead of an elbow so that i could add more needle valves in the future as needed for more tanks.****
Part No. SS-2-CP Pipe Cap, 1/8 in. Female NPT
Part No. SS-4-HLN-2.00 Hex Long Nipple, 1/4 in. Male NPT, 2 in. Length
From ebay -
SS Burkert Solenoid 1/8 NPT 4W 115PSI 2 way 200 A 200A Valve 6011
****There are many solenoids available out there ranging in price from $30-100 bucks****
Replacement Matheson gauges 2.5" plated brass 0-200 psi and 0-3000 psi
Metering valve -
Dakota Brass High Precision Metering Needle Valve - 90 Degree Flow Pattern
6AMV1120 Maximum Flow Rate: Air - 200 mL/min, Water - 6 mL/min, 0.042 Orifice, 0.0008 Cv
****I upgraded the old JBJ with this metering valve a year ago and transferred it to this new build****
This an older guide to many of the metering valves suited to our use.
Needle Valve guide
Small flathead screwdriver
Bench mounted vise
Pair of adjustable wrenches
Pipe wrench or pliers can be used but they *will* mar the finish.
Teflon tape from any hardware store
Small, thin, pointy object to clean gunk from threads
Small dish with a 75/25 dish soap & water mix to check for leaks
New teflon seal or O ring for your reg to tank connection
Pad your vise with a folded towel to avoid marring the regulators finish
Lay our your parts to make sure you have everything you need
Prep all the threads with Teflon tape. Make sure you put the tape on in a counterclockwise direction to avoid it coming off when you thread the part in.
The ports on your regulator should be labelled as HP (high pressure) or LP (low pressure). When you remove the CGA nipple, gauges or outlet parts, label the ports so you know where the new parts go.
Thread your parts in finger tight, then use your wrench to tighten 1.5-2 more turns. Be careful to not over tighten anything as it could damage the part or the regulator.
The gauges can be tricky to get aligned correctly with a good seal. They are the most commonly over tightened parts when building a reg.
If you noticed my gauge being the wrong one for the high pressure port, you win a gold star! I ordered a high and low pressure but was sent two low pressure gauges. I reordered direct from Matheson to get the right ones. They show up later in this post.
Lay out your components in the order you're attaching them. Pay close attention to the flow direction of the solenoid. Very important you get this correct.
This is another part you'll have to be careful of over tightening as you align the elbow direction.
Again, the flow direction of the solenoid is very important when you attach it.
For my build, I wanted the solenoid plugs pointed to the rear of the reg. Your build may vary depending upon what 'noid you get.
This Burkert 'noid came wired. Not all do. In this case the washer needs to be aligned correctly and installed to prevent moisture from getting inside the unit.
Here I aligned the 3 way tee and installed the cap on the open end. You can use an elbow here but I wanted to be able to add more metering valves and ports for more tanks in the future.
Here it is fully built before leak testing. Note the Metheson gauges and the needle valve are installed. Looks much cleaner with them in my opinion vs the no name brand ones I initially ordered.
There you go. By no means is this a complete guide or instruction manual for doing this project. The sheer volume of parts and information out there can be bewildering and confusing without having a background or knowledge base to work from. You will need to do more research to suit the regulator or parts you end up choosing to use. Hopefully this will serve as a primer to help you get started.
I hope you found this useful or interesting. If there is something I missed or you'd like added to this primer, please do let me know. I enjoy feedback and the occasional raspberry 😝for making mistakes or leaving something out.
PS I don't have a SO to question my judgement for the money spent on this project so I'll lay out my costs here haha. You can do this much more cheaply than I with brass parts and less expensive MV/solenoid. As little as $50 combined for the MV/solenoid that are brand new.
Used reg - $40 ( new is about $350)
New replacement gauges $52
SS Burkert solenoid (pre-wired) $75
Dakota MV $90
Swagelok pipe fittings about $85
Teflon tape <$2
CGA 320 nipple/nut $20
You should already have tissues to handle the tears due to an empty wallet if you go my route 😂
PPS I should note that I have never bought a new dual stage CO2 regulator kit but have recommended the one sold by NilocG as it looks like a great kit for about $250. I went this route for the fun of the project as well as control of every part involved. I know exactly what I'm getting from the parts chosen for the build. Unless you get a dud regulator from ebay, but there are always risks going the DIY route.