# A couple of regulator questions before I pull the trigger on eBay



## jseyfert3 (Apr 9, 2012)

Hopefully, the horse isn't too dead on this one. I did some searching, and didn't quite find what I was looking for. I'm setting up my first planted tank (more in the future, most likely), and building my own regulator system seems to be the best route, with a used regulator off eBay, some fittings, and a good needle valve.

Some searching brought up a couple pretty cheap used brands, one of which is the Matheson 8, of which there are a few on eBay with prices around $35-60 with $15 shipping. Which brings the following questions:

The 8-320 model. What does the 320 mean?
If it is silver, does that mean it's made of stainless or could it be aluminum? Does it really matter? Would brass work just as well?
When comparing different used units of the same type vs price, what should I look for? Threads already connected? What sort of wear? For example, does this appear to be a good one?
Fittings. If the supplied fitting for the CO2 tank doesn't work, what sort of fitting do I need to purchase to fit the CO2 tank? What other fittings do I need to buy to connect to a needle valve?
Speaking of needle valves, what are some good quality ones that won't break the bank?
What connectors/adapters do I need to go from the needle valve to standard aquarium airline? At the moment, no solenoid is planned, and my bubble counter I ordered installs inline on the airline and not directly to a needle valve.
Finally, as I have a dual side-by-side custom DIY stand for two 20 gallon longs (or two 29 gallon tanks, if desired in the future for plant height), I will want to expand from one tank to the second off the same bottle. Do I simply need a Y-valve after the regulator and a second needle valve, or would I need a high pressure Y off the tank and two regulators, or a mid-pressure regulator off the tank and a Y after it with two more regulators after the Y?

I apologize for the amount of questions, however, I do plan to pass this information on to new members someday, so it will not be wasted. Also, this is my last purchase (besides a local CO2 tank) before I'll be ready to go, so I'm getting excited and don't want to spend hours on further searching, just to find I missed an adapter when I'm putting it all together and have to wait an extra week when I have everything else. 

Thank you in advance!


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## jseyfert3 (Apr 9, 2012)

Never mind, I put in about another 5 hours of research and pulled the trigger myself. Take care all. 

If anyone would like to know what I got for reference, post here, and when my system is up and running, I'll fill you in on the details.


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## neilshieh (Jun 24, 2010)

jseyfert3 said:


> The 8-320 model. What does the 320 mean?




320 refers to the gas inlet connection. in our case we need cga 320. you have to look at the pictures though, there's no guarantee the previous owner did not swap out the inlet already


jseyfert3 said:


> [*]If it is silver, does that mean it's made of stainless or could it be aluminum? Does it really matter? Would brass work just as well?


If it's silver it means it's chrome plated. I'm pretty sure I know which auction you were looking at/bought (way overpriced imo but thats up for you to decide) Stainless steel is more a brushed grey color, if its shiny and mirror like it's chrome. 


jseyfert3 said:


> [*]When comparing different used units of the same type vs price, what should I look for? Threads already connected? What sort of wear? For example, does this appear to be a good one?


when looking for a co2 regulator there are many factors to consider. It gets terribly confusing with all the model numbers and w/e but with a little bit of research or help finding one for cheap is easy. The one you linked to is single stage, and horribly overpriced just saying. you can find a dual stage model 8 matheson for at most 40 dollars shipped. The inlet is a cga 350 so you'll have to buy a replacement cga 320 inlet. One important thing though, the model 8 mathesons along with model 25 harris regulators are old and they use a different type of cga 320 inlet. What you're looking for is the 1/2-27 threaded cga 320 nipple (cga 320 nuts are standard) i think you can get one for pretty cheap off regulator torch and repair (http://www.regulatortorchrepair.com/store.php/products/cga-320ft-nut-and-nipple) I didn't know about them and had swagelok order one for me. When looking at auctions just know theres a high chance of the regulator being broken or leaking, so when buying a used regulator you have to test it extensively. The inlet gauge needs to be ATLEAST 1000 psi, the outlet gage ideally needs to show any of the ranges and between ranges 0-30,0-60, 0-100, 0-200. negative psi is okay but typically only found on the high end regulators. next, google the model number to find some technical data, you need to make sure the regulator to output atleast 30 psi to be able to run most diffusers. 15 psi is okay but it's really limiting. Lastly use good judgement, if the regulator looks like it's been to hell and back then it's probably broken. You spend more money rebuilding a broken regulator than it costs to buy one used off ebay so make smart buys!


jseyfert3 said:


> [*]Fittings. If the supplied fitting for the CO2 tank doesn't work, what sort of fitting do I need to purchase to fit the CO2 tank? What other fittings do I need to buy to connect to a needle valve?


errrr this is just basic stuff. normally you need a regular cga 320 nut and nipple. most regulators have standard 1/4 fmpt ports. as for post bodies, the connections we use are 1/8 npt, 1/4 npt, 10-32 unf, 1/8 tube, 1/4 tube. this is all just plumbing mumbo jumbo and I don't really want to explain it. at the least you'll need most of the following fittings for every regulator, cga nut and nipple, 1/4 x 1/8 npt bushing, 1/8 nipple. configurations and what not are just for aesthetic purposes for making the post body more compact.


jseyfert3 said:


> [*]Speaking of needle valves, what are some good quality ones that won't break the bank?


don't know what you mean by break the bank because co2 stuff is expensive as hell unless you buy things in bulk or snipe cheap things off ebay. Id say just go with the fabco nv 55-18. There are tons of needle valves/metering valves but that's a whole nother essay for me to write lol. the fabco nv is a decent valve that'll get the job done and to make it easy for you it has 1/8 npt ports. it's easy to get, if you want something better maybe get an ideal valve. it's like 70 ish? but trust me, if youre just building yourself a regulator just go with those two well known valves. looking through 101283 auctions on ebay with swaglok model numbers and stuff is a terrible ordeal. 


jseyfert3 said:


> [*]What connectors/adapters do I need to go from the needle valve to standard aquarium airline? At the moment, no solenoid is planned, and my bubble counter I ordered installs inline on the airline and not directly to a needle valve.


The three types are hose barb, push in fitting, and compression fitting. look them up. push in fittings are the best imo. 


jseyfert3 said:


> [*]Finally, as I have a dual side-by-side custom DIY stand for two 20 gallon longs (or two 29 gallon tanks, if desired in the future for plant height), I will want to expand from one tank to the second off the same bottle. Do I simply need a Y-valve after the regulator and a second needle valve, or would I need a high pressure Y off the tank and two regulators, or a mid-pressure regulator off the tank and a Y after it with two more regulators after the Y?


the former. since you won't be running a solenoid it's really easy and all the parts you want can be bought at homedepot.


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## jseyfert3 (Apr 9, 2012)

neilshieh said:


> when looking for a co2 regulator there are many factors to consider. It gets terribly confusing with all the model numbers and w/e but with a little bit of research or help finding one for cheap is easy. The one you linked to is single stage, and horribly overpriced just saying. you can find a dual stage model 8 matheson for at most 40 dollars shipped. The inlet is a cga 350 so you'll have to buy a replacement cga 320 inlet. One important thing though, the model 8 mathesons along with model 25 harris regulators are old and they use a different type of cga 320 inlet. What you're looking for is the 1/2-27 threaded cga 320 nipple (cga 320 nuts are standard) i think you can get one for pretty cheap off regulator torch and repair (http://www.regulatortorchrepair.com/store.php/products/cga-320ft-nut-and-nipple) I didn't know about them and had swagelok order one for me. When looking at auctions just know theres a high chance of the regulator being broken or leaking, so when buying a used regulator you have to test it extensively. The inlet gauge needs to be ATLEAST 1000 psi, the outlet gage ideally needs to show any of the ranges and between ranges 0-30,0-60, 0-100, 0-200. negative psi is okay but typically only found on the high end regulators. next, google the model number to find some technical data, you need to make sure the regulator to output atleast 30 psi to be able to run most diffusers. 15 psi is okay but it's really limiting. Lastly use good judgement, if the regulator looks like it's been to hell and back then it's probably broken. You spend more money rebuilding a broken regulator than it costs to buy one used off ebay so make smart buys!
> [/LIST]


I realized after I posted I that the one I linked was a 350 and not a 320. I also found a PDF from Matheson and realized 350 are for oxygen and 320 is for CO2, and also refers to connector type used (they must do that so you don't hook the wrong regulator to the wrong gas). Anyhow, I went with this one, was $43.33 shipped. It looks different from the one I linked earlier, hopefully this one is a dual-stage? I did make sure that the seller accepted refunds. There was one that the seller didn't accept refunds on. Yeah... :doubt:

But you are saying that I will need a new regulator to CO2 adapter? Darn...



neilshieh said:


> errrr this is just basic stuff. normally you need a regular cga 320 nut and nipple. most regulators have standard 1/4 fmpt ports. as for post bodies, the connections we use are 1/8 npt, 1/4 npt, 10-32 unf, 1/8 tube, 1/4 tube. this is all just plumbing mumbo jumbo and I don't really want to explain it. at the least you'll need most of the following fittings for every regulator, cga nut and nipple, 1/4 x 1/8 npt bushing, 1/8 nipple. configurations and what not are just for aesthetic purposes for making the post body more compact.





neilshieh said:


> errrr this is just basic stuff. normally you need a regular cga 320 nut and nipple. most regulators have standard 1/4 fmpt ports. as for post bodies, the connections we use are 1/8 npt, 1/4 npt, 10-32 unf, 1/8 tube, 1/4 tube. this is all just plumbing mumbo jumbo and I don't really want to explain it. at the least you'll need most of the following fittings for every regulator, cga nut and nipple, 1/4 x 1/8 npt bushing, 1/8 nipple. configurations and what not are just for aesthetic purposes for making the post body more compact.


I was able to find a guide for the Matheson 8 dual-stage regulators. I ended up sizing everything after the regulator at 10/32. I picked up an adapter (actually a pack of 10) from Clippard, because...



neilshieh said:


> don't know what you mean by break the bank because co2 stuff is expensive as hell unless you buy things in bulk or snipe cheap things off ebay. Id say just go with the fabco nv 55-18. There are tons of needle valves/metering valves but that's a whole nother essay for me to write lol. the fabco nv is a decent valve that'll get the job done and to make it easy for you it has 1/8 npt ports. it's easy to get, if you want something better maybe get an ideal valve. it's like 70 ish? but trust me, if youre just building yourself a regulator just go with those two well known valves. looking through 101283 auctions on ebay with swaglok model numbers and stuff is a terrible ordeal.


...I also picked up a needle valve from them, because...

(Oh, and yeah, this initial setup is by far the most expensive part of my equipment. $170 for my 20 lb tank from the local welding store.)



neilshieh said:


> The three types are hose barb, push in fitting, and compression fitting. look them up. push in fittings are the best imo.


...I also picked up some push on barb fittings from them, because...



neilshieh said:


> the former. since you won't be running a solenoid it's really easy and all the parts you want can be bought at homedepot.


...I changed my mind and decided to get a solenoid. After research, I settled on the Clippard mouse, which uses 10/32 connectors. So I simply decided to make my life easier and size everything after the regulator at 10/32, because not only did the solenoid use it but that was the only size for the push on barbs if I ordered from Clippard.

The good news is because I decided to standardize on 10/32, for my second tank, that Fabco NV-55-18 needle valve you mentioned is only $23 with 10/32 ports vs $34 with 1/8 NPT ones.

And I don't want you to think I blew off all your advice and went with what I wanted, I just simply did more research and came to my own (possibly wrong) conclusions. I guess I really should have waited a little bit before ordering, but I was pretty impatient, as this is the conclusion of one stage of the project (building stand/light/equipment) and the start of another (actually growing plants). I even know someone who is ready to send me starter plants, for free, as soon as it's up and running.

Thank you for your advice, it is appreciated.


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## neilshieh (Jun 24, 2010)

yeah well when I started out with co2 I had LeftC helping me with all my questions  it's always nice to have a co2 builder around on the forum to answer the co2 related questions. Oldpunk and bettatail are two other very knowledgeable people but they mostly reside on TPT. 
anyways, the regulator you bought it good, it's dual stage, and has a cga 320 inlet already. looks kinda old but just buy some brasso and clean it up. At this point your biggest concern is whether the thing works or not. follow these instructions by bettatail, they're great (http://www.plantedtank.net/forums/showthread.php?t=137245)

as for your post body.... when using 10-32 connections you should use stainless steel 10-32 stubs. The brass ones are very weak and shear easily. If you're going to be using clippard mouse solenoids and 10-32 needle valves heres what you'll need. 1/4x1/8 npt bushing, clippard mouse manifold (15490-2), clippard mouse solenoid (manifold version), 10-32 needle valve, 10-32x1/4 tube od hose barb or push in fitting. The problem with 10-32 fittings is that they're weak so you want to try to minimize the number of those fittings as much as possible and use stainless steel 10-32 stubs so it's stronger. 
if you have anymore questions just ask and I'll answer


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## jseyfert3 (Apr 9, 2012)

I didn't think about the weakness part of 10/32, but they are so small it makes sense now that you point it out. What do you mean by stainless steel stubs? I think all my stuff that I ordered was brass. So...I guess I'll just have to be really careful on assembly, and think about 1/8 connectors when I set up the 2nd tank.

I'm glad the regulator I got was good. Thanks for the instructions from bettatail, I read them through and they are simple and complete. I never would have thought to test everything like that.


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## neilshieh (Jun 24, 2010)

http://www.clippard.com/downloads/P...mber/288-327 Fittings and Tubing/Page 307.pdf
the first one, those are what you want to use. they're closed nipples though meaning when you use it to connect two things they'll be right up against each other.

yeah the brass 10-32 nipples are highly susceptible to being over-torqued a good rule of thumb is to tighten fully with your hand and then use a wrench to tighten about 50-80 degrees any more and you'll feel the fitting "give" and then you'll know you broke off the threaded part. honestly best way to know how much you should tighten is to just break one of those nipples first LOL


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## herns (Aug 28, 2007)

I always had a problem with 10/32 when I remove the Co2 tubing during refill. It can easily break when too much force is exerted. I usually cut it with scissor and slice with razor blade the remaining piece on the fitting.


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## jseyfert3 (Apr 9, 2012)

herns said:


> I always had a problem with 10/32 when I remove the Co2 tubing during refill. It can easily break when too much force is exerted. I usually cut it with scissor and slice with razor blade the remaining piece on the fitting.


Why do you have to remove the CO2 tubing during refill?


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## herns (Aug 28, 2007)

It is easier for me to work with the reg without the tubing on especially during refill when I take out the co2 tank off from the stand. 

Sent from HTC One device using Tapatalk2


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## neilshieh (Jun 24, 2010)

get 10-32x1/4 tube od push in fittings then! I hate using barbs for the reasons described by herns.


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