I am trying to set up my high pressure c02 system and am having problems with the needle valve. I have tried a cheap needle valve from home depot and it did not work, it just leaked, and then bought a parker valve from grainger. The parker valve will not give the flow rate of 1 or 2 bubbles a second. Anybody have a needle valve that they use that works. I have set my output pressure at 20 psi and even tried it at 10 psi with no luck on both valves. I am open for suggestions. Thank you in advance