Precise and affordable co2 needle valve

[bizovski]

Hi!

I'm looking after some relative precise but affordable needle valve.

I have co2 art regulator pro-se but the needle valve isn't as precise as I would like it to be. I'm dosing like 9 bps (a bit bigger bubbles in ista intense flow bubble counter). And to dial it from 7-10 bps is like a fraction of degree on needle valve knob.

I looked into some advanced swagelok se series, hikelok (swagelok chinese copy) but they are above $130. The basic aquarium grade valves are like $5 on aliexpress.

I also came across metering valves (dwyer) and some on aliexpress LZB-3. But this one work on pressure of 1bar. I let co2 to reactor with 3bar. I'm not sure if the system would work with 1bar pressure in system.

I figured out i need like 30ml co2 in a minute.

Is there something in the middle range?

 

[Disaronno]

I also came across metering valves (dwyer) and some on aliexpress LZB-3. But this one work on pressure of 1bar. I let co2 to reactor with 3bar. I'm not sure if the system would work with 1bar pressure in system.

@bizovski Flowmeters for gasses are typically calibrated at 1 bar. The flowmeter can definitely be used at 3 bar or higher. Some are even have a max pressure of 13.8 bar but this is unnecessarily high (your soft tubing would burst).

One thing to note, the scale reading printed on the glass tube is not always representative of the amount of gas flowing. Certain flowmeters are calibrated for a certain gas at a certain pressure, these will have accurate scale readings. Otherwise the scale is just there as an indicator.

 

[Zeus.]

Precise, affordable and needle valve are not normally in the same sentence unfortunately.
Cheap ones are normally used and normally acceptable. But good ones are not cheap but i have hear good things about the better ones, even when purchased second hand, @Hanuman has only good things to say about his.