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How to use inline dual stage reg?

hotweldfire

hotweldfire

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23 Mar 2011
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Could I get some advice on how to run this reg? Not how to install it as it is installed fine. However, my confusion is how to make use of it.

The idea is that you set the maximum pressure on the inline using the main valve on the inline to a level to limit the injection rate should the pressure on your main reg get too high because of EOTD, no? Isn't it the case then that the needle valve on the inline is redundant during an EOTD as it will not limit the injection rate, only the main valve will? I.e. the increased pressure from an EOTD will simply override the inline needle valve but not the inline main valve? So I have to get the main valve on the inline set exactly to the level I want and ignore the needle valve on it?

This appears impossible to do as it doesn't provide the precision required. For example, I adjusted the main valve yesterday night so that the injection rate was 54bpm. I have come home tonight to find the injection rate at some uncountable number (somewhere in the 70s I think) with all fish gasping and some looking unlikely to survive the night.

I feel like I'm missing something obvious here so advice would be appreciated.
 
Was your cylinder just filled?

Co2 enters the cylinder freezing cold. As it warms to room temp the gas expands and the bubble rate will increase a little.

When i get my tank filled the gauge indicates the cylinder is just below full. 24hrs later the gauge reads just above full.

I do this with my dupla armature pro:

Turn down your working pressure to around 1 bar or 10-15psi
Set your needle value so it's only just on (almost closed).
Then turn up the working pressure until you get your desired bubble rate (don't go into the red). Fine tune with the working pressure knob, not the needle value (why? because 99% of needle value on store brought regs are useless). I believe GLA in the US is the exception.
 
Hello,

Not sure if I understand you correctly.

This regulator is preventing EOTD by limiting pressure to pressure you will set on this regulator. Needle valve after this regulator is to let you adjust bubble rate.

If you require 3bar, all what you need to do is set inline regulator to 3bar and adjust bubble rate with SMC needle valve. Once this set bubble rate should stay unchanged.
 
Thanks both for posting. CO2Art, I understand what you're describing is how it should work but that's not my experience. The bubble rate in a system with variable pressure is set by the main valve, not the needle valve. This is because an EOTD will override the needle valve. As a result the pressure level set on the inline reg will determine the injection rate during an EOTD.

Let's take your example. The pressure on my jbl reg is set to 2.8 and on the inline to 3. With the inline needle valve fully open this results in 70bpm. I turn down the needle valve to achieve 60bpm. I then get an EOTD and the pressure on the JBL jumps to 3.2. The pressure on the inline now jumps to its max of 3. The injection rate jumps to 70bpm or 80bpm. The solution then is to set the inline reg to around 2.6 to ensure an injection rate of 60 no matter what the needle valve is set to (as it is redundant). However, in reality this is very hard to do as it is difficult to be precise with the main valve and very easy to set it too low and choke the CO2 which is what I described above.

Dantrasy I have reset the valve as per your instructions and will monitor rate. I will report back my findings.
 
hotweldfire said:
Thanks both for posting. CO2Art, I understand what you're describing is how it should work but that's not my experience. The bubble rate in a system with variable pressure is set by the main valve, not the needle valve. This is because an EOTD will override the needle valve. As a result the pressure level set on the inline reg will determine the injection rate during an EOTD.

Let's take your example. The pressure on my jbl reg is set to 2.8 and on the inline to 3. With the inline needle valve fully open this results in 70bpm. I turn down the needle valve to achieve 60bpm. I then get an EOTD and the pressure on the JBL jumps to 3.2. The pressure on the inline now jumps to its max of 3. The injection rate jumps to 70bpm or 80bpm. The solution then is to set the inline reg to around 2.6 to ensure an injection rate of 60 no matter what the needle valve is set to (as it is redundant). However, in reality this is very hard to do as it is difficult to be precise with the main valve and very easy to set it too low and choke the CO2 which is what I described above.

Dantrasy I have reset the valve as per your instructions and will monitor rate. I will report back my findings.
Click to expand...
No you set the pressure required for the particular diffusor with the main valve and you set the flow with the needle valve. The fact that its a dual stage reg will overcome the eotd
 
I am still either misunderstanding something very basic or failing to adequately communicate what seems to me something very basic. Let me try something else.

I open up the inline main and needle valve all the way and the needle valve on my JBL reg. I then turn up the main valve on JBL slowly until I reach the point where I start to get some bubbles coming out of my in tank bazooka atomiser. The JBL reads around 1.65 bar. To get 55 bpm I need to turn the main valve reg up to 2.1 bar. I then turn the JBL needle valve down until it reduces the injection rate and then turn it up ever so slightly so I get 55bpm again.

My question is what psi (as the inline doesn't have a reading in bar) should I set my inline to to avoid an EOTD? Secondly, what should I do with the needle valve on my inline?
 
Hello,

As Andy mentioned, in your case (bazooka diffuser) please set it between 28-32 PSI.

Whole idea of inline regulator is to keep working pressure steady even when your main regulator (JBL) will increase it over what your require (28-32PSI).

What I would suggest is to open fully JBL needle valve, close completely SMC valve in inline regulator. Then adjust working pressure on inline regulator to 28-32PSI and last step is to fine tune bubble rate with SMC valve.

This way if pressure will rise on JBL regulator (EOTD), inline will keep it to what you set (28-32 PSI) and bubble rate won't change as SMC is after inline regulator.

I hope this helps. Let us know if you have further questions.

PS
Thank you Andy for your comments!
 
With an EOTD, I know it's hard to say, but how soon quickly would you expect the 'dump' to last? Would it be over the course of a few days or are we talking minutes/hours?
 
In that case it sounds exactly what happened to me a few weeks ago. Noticed my DC turning yellow, turned down the needle vavle quite a bit but the next day it was still yellow and all my fish were dead... Super depressing.
 
If you put a mark on the service/low pressure gauge when you have a new fe etc then you will see the pressure climb as the fe etc runs out, this will confirm wether you are getting EOTD or not.
Its up to you if you want to buy a dual stage reg or inline as a safety measure. You could just change the cylinder when contents pressure starts to drop
Funny how jbl regs suffer but co2arts cheapy single stage doesn't , you don't always get what you pay for, especially when products are aimed at the aquatic market
Sorry for your losses and i hope you don't have anymore
 
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