What is the pressure drop of an acceptable C02 leak.

[born2dive9702]

Hello everyone, it has been a while since my last visit. I have got my kegerator system up and running, in conjunction with a ICE beer tower, and a chiller with pump.

I have my C02 setup BUT I have a small leak some where.
from the co2 tank to the valves I am using a 1/8" stainless steel hose (high pressure nitrogen hose 4000psi) from the valves I am running 4 inline filters (airtool filters from home depot) (1 for each line) connected to 4 brass shutoff valves connected to 4 stainless steel unions.

Now I have verified that ALL the threads are 1/4" and 1/8" NPT fittings.
First attempt I used only Rectorseal Trueblue sealent and let it sit for 2 days prior to pressurizing the system, the sealent blew out on the stainless fittings immediately loosing pressure quickly with an audiable hiss.

Since then I cleaned off the rector seal and I have wrapped all fittings with 8 passes of Teflon tape.

I pressurized the system and used a flame test, the flame did not go out. I then took a spray bottle with yellow food coloring and liquid soap and spritzed all the fittings. I have not seen any bubbling anywhere to indicate a leak of C02.

BUT with the system pressurized, I turn off the C02 at the tank, and let it stand. I have monitored it carefully (now keep in mind these are 1/8" high pressure line so not as large of volume compared to a 1/4 or 3/8 line.) I have had the tank off for a better part of 4 hours so far, I have lost about 100 psi (Static pressure tank off, no new co2 entering pressurized system)

The concern is this kegerator system is in my apartment, I can not hear, see (with flame test or bubble test) any leaks anywhere.

This is equating to a loss of 25psi (static pressure) every hour. Is this an acceptable loss for a kegerator system??? Tank is outside the cooler.

Please let me know.

 

[Morrey]

Maybe its just the way I roll, but I feel that NO leak is acceptable. I became frustrated with a leak and submerged my entire CO2 keg system in the water filled bath tub. This method WILL find a leak provided your system is not overly complicated like bulkhead air manifold mounts and similar. For standard gas system, submersion is possible, just be careful of submerging gauges as much as possible.

Routine maintenance like replacing seals, washers and use of keg lube helps keep your system in tune.

Just to make sure, are you attaching this static system to a keg of beer? If so, it is possible that the beer is absorbing CO2 slowly making you think there is a leak.

 

[corkybstewart]

No leak is acceptable, you'll be refilling CO2 tanks all the time.
I'm trying to visualize what kind of setup you are running, but I can't.
Can you post a picture of it?

 

[CudaJoe]

Never settle for any leak what so ever. Not a boost leak on your turbo charged car, not a CO_2 leak on your system, not a leak in your Liner pool, Not a leak from HVAC unit in your house, and especially not a leak in your bed from you 9 months pregnant wife.

 

[corkybstewart]

I'm still trying to figure out what you are pressurizing that could lose 100 psi in the first place. I have 2 kegerators-one with Perlick taps set at 12 psi and the other with picnic taps set at 15 psi. If I shut the gas off both systems will eventually show 0 pressure on the regulators, but it takes a while so I figure the gas has been absorbed by the beer. If not, the tanks would eventually leak until they are empty, and it wouldn't take long with even the smallest leak

 

[born2dive9702]

Hello all, I can not submerge the gauges, as they are not waterproof, the plastic cover are not sealed.

I pressurized the system and my tank put 950psi in the system. I closed the valve of the tank and The drop down test has been running for 10 hours now WITH the co2 tank valve closed. after 10 hours I have lost about 250psi it is now at 700psi.

The leak is evidently very very small the question is, Is it of consequence?
Outside of submerging, and a co2 sniffer, is there any other way to find this bugger?

Corky My main pressure going to the manifold is what I am speaking about. full pressure it is at 950psi, it is droping 25psi per hour with the valve closed.

My tank valves are set at 100psi for testing. followed the filters followed by shut off valves. the valves at this moment are closed, and there are no hoses connected to them nor where the hoses are going to connect are the fittings plugged.

I am solely testing the manifold, the filters, and the shutoff valves at this moment.

At this m

 

[born2dive9702]

seeing that the ends of the pipes are not plugged and the hoses to the tanks are not connected, COULD it be that there is a small amount of co2 leaking past the shutoff valves?

 

[corkybstewart]

Any leak should be visible with the soap spray(I use Starsan BTW).Test everything, starting at the gas bottle valve and working your way outward. If there is a leak you will find it. And any leak will reduce the time you have before refilling your tank.
I guess I'm just dense but I still don't understand what you are pressurizing at 100 psi. My CO2 tanks have pressure regulators attached to the bottle, with a hose sending 12 or 15 psi gas to the manifolds, which distribute the gas at those pressures to my kegs. If I raised the pressure to 100 psi there's no telling what would happen, but it would't be good, I know that for a fact.

 

[crane]

Are you sure all of your equipment is rated to handle 100psi? Have you tried this same test at something more realistic like 30psi or under?

 

[Smellyglove]

I'm with the others saying no leak is acceptable. If should not leak, so don't "accept" it if it does. However, your system seems a bit intricate, why? I can't understand how your line of flow is.

In my mind it would would just be Regulator -> Manifold -> Kegs.

 

[SleepyCreekBrews]

It seems like you should be using flare fittings for high pressure , not threaded with teflon tape. I was always told teflon tape is meant for lubrication and anti-seizing , not sealing threads.

 

[V-Fib]

I had a hard leak to find when I 1st set up my kegging system. I lost 10lbs of CO2 in a few days. I couldn't find it using water with dish soap or San Star spray. I submerged everything I could in a water bath and nothing. I actually ended up hearing it. It was from a nipple fitting on the regulator that just needed a 1/4 turn. So if all else fails and you can get things super quite you can try putting your ear to different areas. Also make sure your tank valve is 100% open or closed. Good luck.

 

[Smellyglove]

It seems like you should be using flare fittings for high pressure , not threaded with teflon tape. I was always told teflon tape is meant for lubrication and anti-seizing , not sealing threads.

This seems like a reasonable culprit.

 

[born2dive9702]

Ok here is an update. I have reduced the testing pressures from 80psi to 28 psi on the gauges. I open the co2 tank valve to pressurized the lines. Then close the tank valve and shut off the line valves. So only the manifold down to the shutoff valves are pressurized.first attempt, I have tried only Teflon got bad leaks. So then I tried rector seal yellow, rector seal blew out of the joints. Cleaned it all down with acetone, then tried rector seal blue, same problem sealant blew out of joints. So then I purchased all new fittings in stainless. Tried the rector seal again, and pop went the sealant. So then I placed a thin layer of rector seal blue on the male threads then taped them with 8 winds of Teflon, then sealed this outside again with rector seal blue. This has eliminated all but the mysterious leak.

When I charge the manifold ( with the line valves closed, ) the close the cot tank valve, the manifold holds the 950 it psi and drops very slowly about by 100 psi over 12 hours. Then the pressures drop from 800+ down to 600 over the next 10 hours, then the pressure drops from 600 psi down to 0 in 6 hours. I can not find the leak.

Here are the 3 photos of the manifold. The line valves are in the off position. When I charge the lines and the manifold, then close the line valves, And the co2 tank valve, the lines will stay charged long after the manifold drops to 0 on the manifold gauge. For the system to completely loose all pressure to the manifold with the co2 tank valve off takes about 36 hours.

Ps the inline filters are there to filter out particulates like loose pieces of Teflon from getting in the beer and soda.

What's going wrong

 

[born2dive9702]

The problem leak is some where between the co2 tank and the red line shut off valves.

 

[Bobby_M]

That is a Rube Goldberg machine. You have like 20 more joints than you need. Get rid of the filters and unions for one thing. Proper co2 disconnects are flare.

 

[day_trippr]

Wow. What was trying to be accomplished with that plumbing nightmare?

 

[SleepyCreekBrews]

That line from the tank should be a copper flare line, you don't plumb high pressure gas though flexible line. think about how a scuba regulator is configured.

All that stainless braided line looks like the type of stuff you use for brake lines for motorcycles and jeeps, and (correct me if i'm wrong) is probably not intended for gas.
A simple shutoff valve, hosebarb, and clear vinyl tubing is all you need to feed a keg with 10-15 lbs of cO2.

 

[thomash]

I'll just make a couple points here.

Thread tape and other sealants like rector seal should ONLY be used on pipe thread. They have no place in flared fittings, and actually make things worse, not better.

On flared fittings, the seal is a compression seal between the flared surfaces. The threads are there to provide a clamping force for those surfaces. Other than clamping force, they do absolutely nothing for the seal of the fitting. If the flared fittings are not sealing properly, it's because there is a defect in one of the mating faces. The only way to fix this is to either replace the fittings, or to use something like a flared fitting washer which will deform to the defects in the mating surfaces. For brass fittings, this is not usually necessary because the metal is soft enough that it will deform a bit to allow for a good seal. For stainless flared fittings, it's common to use the washer because the material is much harder.

When sealing pipe thread fittings for gas use, a sealant like rector seal is absolutely the way to go. Teflon thread tape is not recommended for this. The thread grooves need a good coating of the sealant before joining the fitting, and the fitting needs to be good and tight. Also, make sure you give the sealant time to set up before applying pressure to it. Refer to the manufacturers directions on how much time to wait before applying pressure.

Hopefully those are high pressure regulators and not secondaries. I highly recommend you get a primary regulator and attach that directly to the tank. I cringe at the thought of a unregulated hose coming off the tank holding 800 PSI and what that would look like if it ruptures. Even with the appropriate rated hoses, I would still avoid it.

 

[thomash]

Also, make sure you are not trying to attach a pipe thread fitting to a flared fitting. It will never seal.

 

[born2dive9702]

The lines are 1/8 co2/ air lines. They have a burst pressure of 4500 psi. They use these lines in most scuba shops from the bulk tanks to the fill stations and from the fill stations to the scuba tank. I have been diving for 20 year's all over the world. These lines are the most common. They screw it into the HP connector that connects to the tank with just a npt fitting, so I don't think they are anything to worry about.

That line from the tank should be a copper flare line, you don't plumb high pressure gas though flexible line. think about how a scuba regulator is configured.

All that stainless braided line looks like the type of stuff you use for brake lines for motorcycles and jeeps, and (correct me if i'm wrong) is probably not intended for gas.
A simple shutoff valve, hosebarb, and clear vinyl tubing is all you need to feed a keg with 10-15 lbs of cO2.

 

[born2dive9702]

Duly noted. But the problem is ABOVE THE UNIONS if you noticed the shut off valves are closed. There are no leaks down stream after the shut off valves.

So this means that the unions and everything below them are holding constant, and are not leaking.

The problem is between the tank and the line shutoff valves.

I have filled the filters with water then pressurized the system with the line valves closed, there is no water coming out of them from the top of the filter to the shut off valves that would indicate a leak.

That is a Rube Goldberg machine. You have like 20 more joints than you need. Get rid of the filters and unions for one thing. Proper co2 disconnects are flare.

 

[born2dive9702]

I can not use final tubing for 3 reasons.

1 the lines are going from the outside of the freezer to the inside, the metal has abraraded the final lines causing them to burst.

2. We live in an area where there are hot sulphur springs. There is a constant supply of sulphur gas that blows down and no matter what it gets into the house. The sulphur eats final like kids eating candy at Halloween. Making the tubes soft and rot out in a few months.

3. I can taste even smallest traces of vinal in the soda when using the vinal tubing as gas line. I get sever allergic reactions from it. It gets a 1000 times worse if the soda sits in the final tubing for any length of time. This is why I used the HP stainless hose, and bevseal barrier seal for the product lines.

I can not drink soda even from a soda fountain machine at most restaurants and gas stations because most use vinal hoses.

That line from the tank should be a copper flare line, you don't plumb high pressure gas though flexible line. think about how a scuba regulator is configured.

All that stainless braided line looks like the type of stuff you use for brake lines for motorcycles and jeeps, and (correct me if i'm wrong) is probably not intended for gas.
A simple shutoff valve, hosebarb, and clear vinyl tubing is all you need to feed a keg with 10-15 lbs of cO2.

 

[born2dive9702]

I have no flare fittings, and I knew not to use sealant on flares.

The unions are npt gas unions, they have a plastic ring to seal them. There is no leak after the shut off valves. So the unions are working at pressure up to 8p psi.

I have sealed the fittings before assembly with rector seal. Not after.

I have replaced all the fittings 3 times tightening them more and more each time. Eventually I have cranked down on them with so much pressure I have broken brass fittings trying to stop the leaks. This is why I went to stainless to get more torque pressure to lock them down without breaking them.

Rector seal does not tell you how long to wait, I have waited up to a week before applying the pressures.

As per the hoses, these stainless hoses are HP scuba hoses, 1/8" And have a burst pressure of 4500 psi. So not likely they will have a problem with blowing out.

I'll just make a couple points here.

Thread tape and other sealants like rector seal should ONLY be used on pipe thread. They have no place in flared fittings, and actually make things worse, not better.

On flared fittings, the seal is a compression seal between the flared surfaces. The threads are there to provide a clamping force for those surfaces. Other than clamping force, they do absolutely nothing for the seal of the fitting. If the flared fittings are not sealing properly, it's because there is a defect in one of the mating faces. The only way to fix this is to either replace the fittings, or to use something like a flared fitting washer which will deform to the defects in the mating surfaces. For brass fittings, this is not usually necessary because the metal is soft enough that it will deform a bit to allow for a good seal. For stainless flared fittings, it's common to use the washer because the material is much harder.

When sealing pipe thread fittings for gas use, a sealant like rector seal is absolutely the way to go. Teflon thread tape is not recommended for this. The thread grooves need a good coating of the sealant before joining the fitting, and the fitting needs to be good and tight. Also, make sure you give the sealant time to set up before applying pressure to it. Refer to the manufacturers directions on how much time to wait before applying pressure.

Hopefully those are high pressure regulators and not secondaries. I highly recommend you get a primary regulator and attach that directly to the tank. I cringe at the thought of a unregulated hose coming off the tank holding 800 PSI and what that would look like if it ruptures. Even with the appropriate rated hoses, I would still avoid it.

 

[born2dive9702]

Would taking a tap and die over a the fittings help if the have mating issues? You know thread chasing.

I can not crank them any tighter as they are already starting to deform the hex part where you put the wrenches.

I am at a total loss, as i can not see not hear any co2 leaking.

I am ready to invest in a digital co2 sniffer to find the leak. Do these work well? Has any one tried one to find this type of leak?

 

[NeoBrew]

My system is much more conventional than yours with vinyl tubing all through. I have my primary regulator at the tank which runs into the keggerator and then have a 5 station secondary regulator inside.

I originally set the primary regulator to 40psi and then used the secondary regulators to back that down to serving pressure. I had the same kind of slow leak that drained the tank in a few days. I could not find a leak. When I backed the primary regulator down to 20psi, the leak went away. It's been working great ever since.

Getting rid of your high pressure line and adding a primary regulator might help. You are fighting a lot of pressure there.

 

[thomash]

The cheapest and easiest way to check for leaks is to buy some leak detector solution, or make some yourself by diluting some liquid dish soap with water. Turn on the CO2, and apply the solution liberally to each fitting one at a time and watch for any bubbles forming.

 

[thomash]

Also, if I had to guess, the most likely source of your leak is going to be the water seperators that you have installed right before the shutoff valves. I've used these many times on air compressor lines to help protect my air tools and they rarely are leak proof. The shrader valve, and the top and bottom bowl seals are extremely prone to leaks.

IMO, the water separators are completely unnecessary in a CO2 system, and I would remove them.

Also, the one thing I don't see in your system, from a safety standpoint that you may want to consider is a pressure relief/over-pressure valve on the high pressure side. Not only would it protect you from overpressure situations, but would also give you an easy way to vent the high pressure side before disconnecting from the CO2 tank.

 

[Smellyglove]

It's just way to much plumbing in the line.

 

[born2dive9702]

Well I have finally found the leaks. Not one of the fittings were leaking. I submerged all the fittings and finally the hoses in water and used a halogen light.

On the high pressure line, where the stainless tubes are crimped down around the inside barb. Some of the lines apparently are not crimped tight enough (or maybe too tight) and were leaking UNDER the braid. There also (maybe due to capillary action) micro air bubbles are creeping up along the entire length of the hoses.

So I am going to switch back to my black 2750psi pneumatic hose by Easton that came with my regulators. This should eliminate these leaks. I guess I will use cut off the stainless steel braid from a 5/8 water hose and put it over the black 2750psi line. to dress it up.

 

[born2dive9702]

Now I have another question.

I CAN NOT use PVC /vinyl because
1. I CAN HAVE SEVER allergic reactions to it (all my product lines are accu bev seal with barrier to prevent it getting into the soda)
2. I can taste it even in minute traces ( I can not drink soda from soda machines in gas stations or at restaurant because most of the machines use vinyl hoses for their product lines. it is not as bad if they use vinyl on the gas lines but I still can taste and smell it.)

As mentioned in my previous post, I found leaks in the stainless steel lines where they are crimped, and possibly along the line its self. I have a invisible leaks down stream of each of the 4 regulators AND THE FITTINGS AND FILTERS ARE NOT THE PROBLEM checked with immersing in water no bubbles at all. My suspicion is the stainless steel lines are leaking. I am loosing about 6.7g/hr of co2.

I need the lines to be flexible so I can open and close the lid on the cooler.
I can not use copper as the sulphur in the air where I live turns it carbon black.
I am allergic to PVC

On the low side, after the regulators, the lines are pressurized at 22-25 psi for the co2 to the kegs.

I was thinking of using 1/4" stainless steel braided flexible ice maker water line because it has a working pressure of up to 120psi which is more than any pressure I will have coming off the regulators.

So here is my question.
Has any one ever used 1/4" stainless steel braid flexible ice maker water line for piping the co2 to their tanks??
Has it been successful???

What is the inner core of the stainless steel water lines made of??? I can not find specifically what they are made of when I googled it. all I have found is some have a poly inner core. Poly what???? poly vinyl chloride, poly ethelene, poly butelene,

I thought they were made more commonly of nylon?

Please let me know.

 

[day_trippr]

Why not just use Bev Seal Ultra 235 for the gas lines, too?

Cheers!

 

[born2dive9702]

It's a thought, but I really was looking for something pre made with braid, that is more flexible than bev seal. Bev seal is still too stiff for my liking.

How could I attach a braid on it with a crimp?

Why not just use Bev Seal Ultra 235 for the gas lines, too?

Cheers!

 

[day_trippr]

Screw the braid.

You're already running the Ultra for beer, you can use JG fittings to make them tit easy to install on a normalized regulator stem and a keg post coupler. No vinyl, no nightmare of leaky fittings and poorly crimped hoses just begging to spring a leak at the least provocation.

If I had to live with that mess I'd switch back to bottling

Cheers!

 

[Smellyglove]

What about LLDPE?

 

[mulletmaster]

Well I have finally found the leaks. Not one of the fittings were leaking. I submerged all the fittings and finally the hoses in water and used a halogen light.

On the high pressure line, where the stainless tubes are crimped down around the inside barb. Some of the lines apparently are not crimped tight enough (or maybe too tight) and were leaking UNDER the braid. There also (maybe due to capillary action) micro air bubbles are creeping up along the entire length of the hoses.

Was it the end that connected to the manifold? That end looks like it had a pretty extreme bend after the hose socket (crimped collar on hose od) I have seen many failed hoses due to that at work. Industry standard is one inch of straight length before bending on hoses that size.

 

[born2dive9702]

It was on almost every hose where they crimped it. It is not bad at all if you use the lines for filling.... But for beer/soda where the line is static, that can loose a decent amount of pressure over 24 hours.

Was it the end that connected to the manifold? That end looks like it had a pretty extreme bend after the hose socket (crimped collar on hose od) I have seen many failed hoses due to that at work. Industry standard is one inch of straight length before bending on hoses that size.

 

[acidrain]

I highly recommend you get a primary regulator and attach that directly to the tank. I cringe at the thought of a unregulated hose coming off the tank holding 800 PSI and what that would look like if it ruptures. Even with the appropriate rated hoses, I would still avoid it.

This^

Also, you can't really measure Co2 loss by pressure drop... Co2 is different pressures at different temperatures.
As soon as you use some co2, the pressure will drop because the liquid Co2 (measured by weight, not pressure) will chill slightly because of the high pressure to low pressure thermodynamics.
As long as there is liquid co2 in the tank, and it remains the same temperature, the pressure will remain the same no matter how many leaks you have.