• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
  • You can now follow UKAPS on Instagram.

faulty needle valve symptoms ?

eminor

Member
Joined
5 Feb 2021
Messages
569
Location
France
Hello, could you tell me what are a faulty needle valve symptoms ? thx
 
Last edited:

Yugang

Member
Joined
13 Mar 2021
Messages
585
Location
Hong Kong
Well, if it doesn't do what it is supposed to do - provide a stable, adjustable, low flow of CO2.

It would be helpful if you could be more specific what is the problem you want to address
 
Joined
20 Dec 2019
Messages
557
Location
South Carolina
Low end valves “float” which essentially means they cannot maintain the aperture you set it at. For instance you set it for one bubble per second. The next day it’s now 5 bubbles a second or barely a bubble every ten seconds, see what I’m getting at? Some people get away with the cheap stuff, others spend the money on a quality valve. They are very expensive nowadays
 

eminor

Member
Thread starter
Joined
5 Feb 2021
Messages
569
Location
France
Well, if it doesn't do what it is supposed to do - provide a stable, adjustable, low flow of CO2.

It would be helpful if you could be more specific what is the problem you want to address
well, the bps are set @ 1bps, the morning the flow is stable, in the afternoon, i get 1.5 to 2 bps, the next morning, i get 1bps again... i though it was the temperature but she stay the same

Low end valves “float” which essentially means they cannot maintain the aperture you set it at. For instance you set it for one bubble per second. The next day it’s now 5 bubbles a second or barely a bubble every ten seconds, see what I’m getting at? Some people get away with the cheap stuff, others spend the money on a quality valve. They are very expensive nowadays
yes if i understand well, needle valve is the heart of the co2 system, quality need to be high to avoid instability and algae ?
 

ian_m

Global Moderator
UKAPS Team
Joined
25 Jan 2012
Messages
5,368
Location
Eastleigh
How much piping have you got between the various items ?
Having a long length of tubing between needle valve and diffuser is known to cause issues do to the tubing pressurising slowly, diffuser "burp injecting", depressurising the tubing, injection stopping until tube pressurises again and repeat. Try to get the needle valve as close as possible to injector. Make sure you are using proper CO2 rated tubing as well.
 

eminor

Member
Thread starter
Joined
5 Feb 2021
Messages
569
Location
France
How much piping have you got between the various items ?
Having a long length of tubing between needle valve and diffuser is known to cause issues do to the tubing pressurising slowly, diffuser "burp injecting", depressurising the tubing, injection stopping until tube pressurises again and repeat. Try to get the needle valve as close as possible to injector. Make sure you are using proper CO2 rated tubing as well.
less than 30cm between the needle valve and the diffuser, does check valve can cause that kind of issue ?

i have jbl special co2 black tube
 

arcturus

Member
Joined
6 May 2021
Messages
444
Location
DE
less than 30cm between the needle valve and the diffuser, does check valve can cause that kind of issue ?

i have jbl special co2 black tube
Yes, the check valve can also cause issues. Do you have a stainless steel CO2 resistant check valve? Normal check valves for air circuits can deteriorate due to the acidity of CO2. Have you checked for leaks in the CO2 pipes, bubble counter, and check valve? What type of diffuser are you using? Is it an inline diffuser? If yes, what is the regulated CO2 pressure you are using? Is the CO2 diffuser clean? Does this problem still happen if you use a different CO2 diffuser (for example in tank diffuser instead of inline diffuser)? In any case the problem you describe can be related to the needle valve - as others said, a quality needle valve that can keep its regulation can be quite expensive. But you need to describe your setup in more detail...
 

eminor

Member
Thread starter
Joined
5 Feb 2021
Messages
569
Location
France
pictures worth thousands of words, you'll get both =)

i checked eveywhere, i spotted a leak, which i fixed with PTFE, there is no leak anymore, the jbl co2 tube is really old (10 yo), is that a problem ?

20220208_143950.jpg
30 psi pressure
20220208_144009.jpg
there was a solenoid but it dont work anymore, so i bought a new one which you'll see soon, i still can't figure if it's a single or dual stage regulator
20220208_143852.jpg

20220208_143858.jpg

20220208_143902.jpg


solenoid and check valve, i was thinking about removing the check valve, because there is no way water come though, the tube is higher than the atomizer
20220208_143923.jpg
inline atomizer
20220208_143936.jpg
 

Attachments

  • 20220208_143910.jpg
    20220208_143910.jpg
    3.9 MB · Views: 45

arcturus

Member
Joined
6 May 2021
Messages
444
Location
DE
I would try to shorten all the CO2 pipes as much as possible. Try to place the solenoid closer to the needle valve and shorten the pipe from the solenoid to the diffuser. And make sure those pipes are as straight as possible (currently the pipe is bent around the diffuser). All that PTFE around the connections does not inspire much confidence...

Do you have the same issue with the needle valve if you use an in-tank diffuser? You may try lowering the regulated pressure a bit with an in-tank diffuser to check if the needle valve can keep its settings longer. But if the problems continue after adjusting the pipes and operating the system at a lower pressure, then it is very likely an issue with the needle valve.
 

ian_m

Global Moderator
UKAPS Team
Joined
25 Jan 2012
Messages
5,368
Location
Eastleigh
I also had issues once, with a cracked bubble counter, that allowed gas to escape in bursts when pressurised. Had issues setting and maintaining bubble count, dunked bubble counter in jug of water, no leak initially, bubble rate built up, could see mist of CO2 appearing in tank, then suddenly mass of bubbles escaping from bubble counter (crack was under the sealing O ring), injection stopped, bubble count went high as system repressurised and after a while situation just repeated, stable'ish injection, then nothing.... First notice when FE ran out after 30 days instead of normal 100 odd days. Took a while to locate the issue.
 
Top