c02 needle valves

[muskieswen]

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

[bobalston]

Depending on the specific valve, Parker makes GREAT needle valves for aquaria usage. I personally use the Clippard valve, as do lots of other people.

For lots of info on needle valves look here:

http://members.cox.net/tulsaalstons/Documents/Aquarium%20Needle-Metering%20Valve%20Recommendations.htm

For other info on pressurized co2 look here:

http://members.cox.net/tulsaalstons/AquaticPlants.htm#High%20Pressure%20CO2

Bob :D

[djlen]

I don't understand.....what do you mean by, "won't give the flow rate of 1 to 2 bubbles a second"?
You should have no problem setting a flow rate with a Parker.

Len

[muskieswen]

djlen,
I have the valve closed all the way and there is still a steady stream of bubbles. Granted I have no clue what the heck I am really doing but I thought i was supposed to try for a starting point of 1 to 2 bubbles a second out of the needle valve. The valve according to the grainger manual is a parker model number PF400B with a cv rating of .78. Any suggestions?

[bobalston]

That valve is wrong. The openings are too big. My clippard has a max cv of .004 Good Parker and Swagelok valves have max cv of .004 to .007. And a really nice parker valve has a cv of .0004

Do take a look at the link I recommended above.

Bob

[djlen]

Sounds like a bad valve. Can you take it back or is it even worth the effort?
If not go here:http://www.clippard.com/store/search.asp?sku=&description1=needle+valves&andOr=and&description2=

If you look down the list you will see model MNV2. I use that one in two of my tanks and like it because it is adjusted by via screw driver which makes minute adjustments easier for me, and also makes it tougher to accidentally turn. However there are many other models with burl knobs for adjusting. I know many people use the KNV1KP.
Clippard, IMO makes the best and most reliable valves for our purposes.
Anyway, once you decide which one you want, look to the left on the page and click on distributors and find one close to you. If there is one nearby, you'll save on shipping costs. (acknowledgment to Bob Alston who clued me in to this feature...Clippard has distributors all over the place).
One last thing.....when you pick up the valve, make sure they give you a set of screw in nipples for the intake and outflows. They should come with it. To be on the safe side, take a piece of your air line with you to show the guy at the distributorship, for sizing.

Len

[muskieswen]

thanks for the info.

[125gJoe]

It could be a bad valve, but it took mine 3 days or so to get a good stable bubble rate. I also heard Clippards are a good one..

[muskieswen]

djlen,
Got the clippard mnv2 valve. You are right, this is the one to get and it was only 6 bucks. Thank you for the information. It is truly appreciated.

[bobalston]

Muskieswen

Sorry the info I posted above wasn't helpful to you in figuring out your problem.

Bob ;)

[muskieswen]

bobalston,
That is quite alright. You should check out these clippard valves. For the price i'm not sure if you can beat them. The link you suggested was very good.

[bobalston]

Thanks. Actually, I was feeling left out of the discussion, despite posting twice. I mentioned using the clippard valve, first I think. And if you looked at my web site, you would have seen lots of info about needle valves and info on my configuration which uses the clippard needle valve.

YOu would also have seen the best valve available is make by Parker, and another one by Parker and one by Swagelock are also very good and superior to the clippard valve. However, the clippard is widely used and a good value for its relatively low price.

Hope you got the system working properly for you, now that you got rid of the valve that was obviously the wrong kind of valve for low volume co2 that our systems need.

Cheers.

Bob :D