item for my co2 system..
Swagelok fine metering needle valve, B-SS4..chose this one because of the good reviews of it in the net.....
“The valve is fantastic, allowing me total extremely fine control over my CO2 flow rate. I can wind the rate from about 1 bubble every 5 minutes, to about 4-5 bubbles a second, linearly, if the inlet pressure remains constant. Changing the inlet pressure allows me a greater control range.”
“The S series is not designed for shutoff service. The handle has ben placed on the shaft to bottom out and prevent the needle from going lower than a specified level. That level corresponds to about 5 bubbles/second with 12 psi across the valve. You will probably have to loosen the set screw and move the valve back 1/8 inch to go to lower flow rates. I have lowered mine to the 1/2 bubble /sec range, with 12 psi across each valve. (remember I have two in series with 24 psi across the pair). I could go lower, but its not needed. What I really like is the ease of control. For instance, I had 0.6 bubbles/sec. I added 1/4 turn to each valve, and the flowrate increased to 0.8 bubble/second. No other needle valve can do that.”