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Things they never tell you about CO2 equipment!

78K views 48 replies 23 participants last post by  mistergreen 
#1 ·
I've had a few issues with my CO2 regulators and solenoids. I haven't been able to figure out why I keep having issues. I have 3 types of regulators, 2 of which were purchased at different places. In a attempt to get things solved I called Orlando at Greenleafaquariums.com. He has GREAT customer service. While he was attempting to help me over the phone I discovered several things I was or was not doing. No one every told me, there were never in any instructions about this. Since I'm not a scuba diver or any other such "pressure tank" user I have had no previous life with this type equipment. I've wondered how many others like me don't know this stuff. I thought I'd post.

1. BEFORE attaching a regulator to a filled CO2 tank, open the tank valve and let some CO2 shoot out. This will clear out any debris that may have lodged and is waiting to clog your regulator.

2. BEFORE attaching or detaching your regulator from your CO2 tank always adjust your working pressure down to zero. Putting on a filled CO2 tank with your working pressure more than zero could blow out your regulator dial. The only exception to this are the preset regulators. (I have one of those.)

3. NEVER run your CO2 tanks empty. Running them empty can cause any settled debris to be blown into your regulator, clogging it.

4. If your bubble counter seems to be clogged turn off your CO2, gently screw off your bubble counter and then turn your working pressure up to 40, turn the CO2 back on blowing any clogged debris out. Turn off and on about 5 times for about 2 secs. to make sure any debris is blown out of the system. Remember to turn your working pressure back down to 10 when you are done and reconnect your bubble counter.

5. If your solenoid seems stuck follow the above directions for the bubble counter in #4.

6. It's best to always use a new washer between your regulator and the CO2 tank unless you have a perma washer. (These perma washers are great!)

If anyone has something else to add please feel free. It sure will cut down on the headaches!
 
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#6 ·
I wish I had known it before buying one for my shrimp tank.:mad:

The regulator on my 75 has a brass to brass connection - no seals needed. It came from a welding tank setup. I used the 5# tank for awhile and fitted the connector piece from the CO2 welding regulator to a new Med-Tech high quality regulator from an oxygen set up. I only have to adjust it twice a year when we go from cold to warm and warm to cold seasons.
 
#9 ·
I use thread tape on my Milwaukee regulator and wouldnt run it without it. Even calling the techs they said it's a pretty good idea just put it on neatly. I put mine on in the opposite direction the threads screw on so that it only gets tighter when i put the fitting on. Never had a problem.

I follow the milwaukee website directions when i'm changing my tank so i dont blow a guage or a regulator... way to expensive to do something that silly. I havent had to do it in over a year and a half the time is comming soon so we will find out.

To contribute to this thread, if your going to shut your CO2 off, do not leave water in the bubble counter. It becomes stagnant and gross and will clog the needle valve under the BC.
 
#11 ·
I'm with TAB - I know they do, but cant imagine why they recommend tape on the threads - the threads are not supposed to be part of the seal. I did also use tape in the past, and it did help when I reused used nylon washers. After being mashed up for a long time, they don't seem to make a good seal for me anymore. Also, they can be a real pain to dig out when they compress into the regulator nut threads. The guys at the welding place where I exchange tanks were very unhappy when I left tape on the threads, so I had to clean it off well before I exchanged tanks. They gave me the standard lecture that we see here every so often -- dont tape the threads, make a good seal without it.

best to find a good seal that mates the regulator inlet to the cylinder. The threads are only to tighten the regulator to the cylinder, not to provide a sealing surface.

Using oil in the bubble counter is better than using water. Water fouls, like mentioned before. Also - after a long time running, the water will eventually leave the bubble counter but the oil stays for me.
 
#13 ·
This is a great thread. I've seen some things that I do not do. Need to change.
When I have my tank filled, I buy 4 or 5 plastic seals. They are not that expensive and I don't want to chance a leak. I use a small tyrap and attach them to the regulator.
Also, a new seal will "crunch" when the connection is tightened adequately.
I'm not sure an old plastic seal will do that. The used seals have a groove cut in them.

I also use glycerin in the bubble counter. The viscosity is enough to count bubbles and if some gets into the water no harm is done.
Charles
 
#15 ·
asshappard,
If what you have in the picture is an MA975 then it is totally different than the one I have. Yours looks much more durable and as I said, the face on the regulator connector to the tank connection does not have the groove in it for the nylon washer. When I take my two regulators apart I will post some pictures.
Thanks for the help.
 
#16 ·
This thread is great. I wanted to add that white tape doesn't do anything to seal any fittings - they aren't meant to. The tape is to keep the threads from cross-threading or settling over extended periods of time. Metal expands and contracts and if the threads are expanding into other metals, they can difform to fill in what space is available. This leads to problems when you unthread them and rethread them if they aren't put back into the exact same space - you'll have a leak. Thus, tape cushions the metal and doesn't seal it. The metal does the sealing. I learned this from work (I work at a hardware store) and my uncle confimed it - he is one of five master plumbers in West Virginia.
 
#18 ·
unlike plumbing threads, threads used for high presure gas and hydrolic fits are strait threads, they do not have any taper too them. if you compare them side by side it will become clear. by adding tape to the male thread, what you are actually doing is increasing the thread size. Which will help them seal. thats just fine for tapered threads, but strait threads you can actually deform/crack the fittings with tape.

If a building inspector were to see any type of sealent( yes tape is a sealent) on any high presure gas or hydrolic lines, they would fail your inspection and most likly make you take every thing apart.

If I went into a welding shop and saw tape on any of thier gas tanks, I'd get as far as I could away from that shop. When full they can be 1300 psi. They are litterly a bomb.



now thats a very small tank at low presure( its a paint ball gun tank)

note natueral gas and propane lines are not high presure, they run at no more then about 15 psi. with the average being in the 10-12 range.
 
#20 ·
I looked into the thread situation for the CO2 bottles and regulators before I spoke even thou I thought I knew the answer from doing piping for years, many years ago. They are what is called NPT = National Pipe Thread. Same as on piping. They do have a taper. Hydraulic lines tend to use ferrels to seal the connection. Pipe dope is used all the time on water, steam and gas.
 
#19 ·
question: how about this product?

http://www.homebrewing.org/CO2-regulator-to-Paintball-tank-Adapter_p_52-1122.html

basically, the adapter has a hole off center and pushes on the paintball tank valve and you attach your regulator to it. the nylon washer presses from regulator onto the adapter (w/c is fine) but from the thread of the adapter to the tank, should it be left as is with no tape?

there's no parts pressed together and my first thought was that the thread will be the only place to leak, if ever.
 
#24 ·
ashappard,
The only place I've ever seen teflon tape used on regulators is on the gauges and other connections. I've been in manufacturing engineering for over 25 years and seen lots of equipment. Teflon tape and various types of teflon paste and pipe dopes are used all the time on water, steam and gas piping. You do need to becareful not to overtighten.

As soon as I need to remove my MA957 to refill the bottle I will be removing the teflon tape.
 
#26 ·
just trying to keep the discussion relevant - I can understand all the myriad ways that piping connections are made -- in the case of regulator to cylinder, tape isn't advised when I talk to welders. These folks say need for tape means the reg isn't sealing proper, I cant really argue with that. I taped my MA957s for quite a while and took flack at the shops for it, but mostly shrugged it off, because the forum guys and my Milwaukee instructions said thats how to do it. So if anything hopefully this is a discussion about how to get a great seal without lots of hassle?

When I came across permaseals it was excellent. Quicker changeover, less worry about leaks and no more taping. I have had to change o-rings on permaseals. They get ragged after a while. Lucky for me, I got the shop I exchange tanks with interested in permaseals and they now stock the orings and the two brass pieces that make up the seal.

seems the board is lighting up recently with pressurized CO2 discussion. Nice.
 
#27 ·
Maybe when I do my weekly maintenance on Monday on my 75 I will take the regulator off.It wont be empty for about a year. I'll take a picture of the nipple and nut connection used on that. No washers/seals, just brass on brass -never had a leak. I think its an argon/CO2 nipple with a female compesssion nut. It was being used this way on a CO2 tank some welders were using to weld 316ss pieces.
 
#28 · (Edited)
I have a friend who has worked for years with medical O2 tanks, regulators, etc on a daily basis. He told me that we should never, ever use tape (or dope) on the high pressure connection between the cylinder and the regulator. Any of the low pressure parts are fine to be taped, though. I totally trust his 15 years of experience with high pressure gas systems.
 
#29 ·
My welding shop also says NO TAPE. I check with Orlando at Greenleafaquariums.com and he also said no tape. He also said no pipe dope.

What I know is that I don't tape, or dope. I use permaseals on two tanks and the nylon washer on the other. No leaks, they last a long time. It's working for me- not broke so I'm not gonna fix it. :D
 
#32 ·
I don't use either because my regulator uses a built in rubber O-ring that is on what I think is called the inlet nipple. It's the part that pressed up against the outlet hole on the Co2 tank when you tighten the nut. I checked for leaks and did not find any. It's now been over two months and I have to do my first tank refill.
 
#30 ·
Yeah, I've never seen a taped connection for the regulator to the tank valve and I'm not sure why Milwaukee tells you to do so but its odd that after a tank hydrotest they always put new tape or dope the threads on the valve stem to the cylinder - steel anyway. I'm not sure about aluminum as you cant see the valve stem threads as it is a different style valve.
 
#31 ·
This is something that I wasn't told until I talked with my local welding supply ... The difference between dual (or two) stage regulators and single stage regulators. They are basically two regulators in one.



DUAL STAGE regulators reduce the source pressure down to the desired delivery pressure in two steps. Each stage consists of a spring, diaphragm, and control valve. The first stage reduces the inlet pressure to about three times the maximum working pressure. The final pressure reduction occurs in the second stage. The advantage of a dual stage regulator is its ability to deliver a constant pressure, even with a decrease in inlet pressure. For example, as a cylinder of gas is depleted, the cylinder pressure drops. Under these conditions, single stage regulators exhibit a "decaying inlet characteristic"; where the delivery pressure increases as a result of the decrease in inlet pressure. In a dual stage regulator, the second stage compensates for this increase, providing a constant delivery pressure regardless of inlet pressure conditions. The dual stage regulator is recommended for applications where a continuous supply of gas is required; such as the gas supplied to analytical instruments where constant delivery pressure is critical.



SINGLE STAGE regulators perform the same function as the two stage regulator using a single step reduction of source to outlet pressure. For this reason, the outlet pressure cannot be as accurately controlled as the source pressure decays. It is highly recommended that single stage regulators only be used in circumstances where the operator can monitor and adjust the regulator as needed or where the regulator is supplied a nearly constant source pressure.
 
#36 ·
There is nothing to seal the nut against the inlet nipple so, I don't think taping the threads will provide a tight seal. If it were to leak, it would most likely leak out of the back of the nut. The nut is only there to force the flat of the nipple against the valve in the cylinder. You need the washer or permaseal at the end of the nipple to form the seal.

Putting tape on the input might cause pieces of tape to enter the regulator. Putting tape on the output won't hurt the regulator but might cause pieces of tape to enter the solenoid.
 
#37 ·
CGA-320 reads are not like NPT tapered threads that need pipe dope or Teflon tape for sealing. A washer fits between the male and female ends that forms a leak free seal when tightened properly.

From: http://fins.actwin.com/aquatic-plants/month.200411/msg00022.html
"Tape is neither necessary nor especially useful. It won't improve the seal and you shouldn't expect it to. The tank should have CGA 320 fitting on it with male threads and the regulator should have CGA 320 female fitting. CGA 320 fittings are *not* like standard pipe threads. With standard pipe threads, the tapered threads provide the seal and using tape or pipe dough helps ensure that the threads don't have any small gaps. But the CGA fittings *do not* seal at the threads! They seal where the flat faces of the two fittings meet and that's why you *must* have a fiber or nylon washer between the two -- to seal the joint where those to seats meet. In fact, applying tape makes it possible to bind the threads before the fittings are fully seated against the washer -- although it would take a lot of tape to do that. ..."

From: http://reefkeeping.com/joomla/index...ctors-in-out-and-everything-in-between-part-1
"The valve used in the cylinder is typically made out of forged brass and in the US has a Compressed Gas Association (CGA) connection type 320 (see diagram) that requires a flat washer to provide the seal. This washer should be replaced every time the regulator is reconnected. Do not use Teflon tape or any other type of sealant but the washer. The company filling the cylinder can provide you with new washers. Note that there are different valve and connection specifications throughout the world, so insure you check your local specifications."
 
#42 ·
I think this is the best description with pictures as well. On a compression type fitting the tape does nothing to help assure a seal. The seal is the washer or gasket top of the bottle and the flange around the regulator. If the gasket or o ring were to leak the tape still would not help as the leak would be around the top hole in the compression nut rather than at its threads.

Now if you had a pipe threading type connection then taping can be a life savior especially if through usage the threads got nicked.
 
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