need help with CO2 injection - manually adjusted valve

**killfire** · 10th Sep 2003, 08:21

Hi,

Have a 2nd hand CO2 bottle fitted with manual adjustment valve. I have problems regulating the flow of CO2. When the knob to the valve is turned (opened) 30-45deg, the flow through the bubble counter is heavy and it is quite impossible to count the number of bubbles. From there I have to slowly tweak the knob towards the close position until I get 1 bubble/second. Problem is, after an hour or so, the flow of CO2 stops by itself...

If I do it the other way around by slowly opening the valve little by little, pausing for a few moments in between increments and observing the bubble counter, I can nvr get a decent bubble count as well. The same as above will happen. Sudden heavy flow etc...

My setup is:

CO2 tank and valve --> bubble counter --> check valve --> CO2 reactor.

Tubing is soft silicone type.

Can those with experience pls kindly advise??

Thanks..

**Amazonia** · 10th Sep 2003, 08:43

Hi
It seem like you are using your main shut-off valve to control your bubble counting.Your CO2 set should come with a regulated gauge and a needle valve. You shouldn't use the main shut-off valve to control. You should use the needle valve to control the bubble counting. If you do not have the regulator and the needle valve get it fix and it cost probably about $30. Hope you get it right this time.

**stressed** · 10th Sep 2003, 13:47

think another possible phenomenon is when u use the taiwan made regulator. I have 01 and have very bad experience with it manz. Horrible....

Thus for this case, only way out is to have it replaced.

**killfire** · 10th Sep 2003, 23:35

Hi,

Thanks for the replies...

I bought the set 2nd hand. It came with a regulator but no throttle or needle valve. I was trying to adjust the bubble count using the knob on the regulator. Had improvised and fitted a needle valve between the check valve and the bubble counter.. The bubble count has been stable at 1 bubble/sec for the last 5 hours =)... think the problem is solved..thanks again....

dx · 11th Sep 2003, 11:34

killfire, where did u get the needle valve and how much is it ? i have the same problem with the regulator (got it 2nd hand too). Don't know how the needle valve looks like also

**geoffrey** · 11th Sep 2003, 11:54

Try Biopast. They will help you fix the needle valve to your regulator. Best to bring your regulator along.

**eric_kclee** · 11th Sep 2003, 13:54

Ki,
Base on you description, you don't have a proper regulator, you are using a manual regulator that using throttle valve to control the flowrate. You problem is very common...due to the manual regulator.

I find your new connection is VERY dangerous..just be careful.

Reason:
The pressure from the CO2 tank is 1000psi, going through the manual regulator without stepping down the pressure. If you open it too much accidently, the 1000psi will rush into you needle valve....and I don't think the needle valve is rated at 1000psi.....when this happens, the valve may get blown up and ... You better be careful of possible flying metal object...may even hit your aquarium.

Just be informed of this possible danger.

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On 9/10/2003 11:35:50 PM

Hi,

Thanks for the replies...

I bought the set 2nd hand. It came with a regulator but no throttle or needle valve. I was trying to adjust the bubble count using the knob on the regulator. Had improvised and fitted a needle valve between the check valve and the bubble counter.. The bubble count has been stable at 1 bubble/sec for the last 5 hours =)... think the problem is solved..thanks again....
----------------

Ki

**killfire** · 12th Sep 2003, 00:28

Hi,

Thanks for the advise. I did not adjust the manual regulator to fully open... I am aware of the pressure in the tank.. had it just a quarter turn open to ensure there is proper flow to the needle valve. The needle valve that I am using is taken from a model airplane engine and is made from stainless steel. Btw, i am sure it is a safe setup as the silicon tubes will definitely unplug themselves if pressure builds up in the line rather than the valve blows itself up...

DX: The needle valve that I am using is very precise since it is used to regulate fuel air mixture in a model engine but the price is a bit steep... would advise you to go for the bioplast option.

dx · 12th Sep 2003, 09:41

Biopast=name of the LFS ? sorry I haven't come across this and also i can't find it in phone book or LFS list. Please tell me where is it, location ? phone no. ?
Thank you thank you.