Aquarium Needle/Metering Valve Recommendations


Needle/Metering Valve Recommendations



#1 Best valve for the price:  Fabco NV-55

    $23 + shipping from Rex Grigg


#2 Better valve - costs more:  Ideal 52-1-12

   Read thread:

   Approx $70 + shipping

   Contact Bill Sand via one of these 3 ways. That's what I do:
   Phone (701) 352-1164

    Fax (701) 352-1165


#3 Like trying out new things?  Taking chances?

     Tunze - #7077/2 "Fine adjustment valve"  approx $11.00

     See below for more info

      If you do try this, please email me with your results:   bobalston9   AT yahoo   D O T   com

#4  Not recommended.  Clippard.  MNV-4K2 – approx $10.10 from local distributor

      Actually they work OK and I have used 2 for several years.  However they are somewhat temper mental and it is not much more $ to get the MUCH BETTER Fabco NV-55.








Needle/Metering Valve - Starting with Very Best and Working Down


0)      Hoke Micro-metering – approx. $175

I put this one here based on Dave Gomberg’s recommendation



1)      Best Metering valve:  Parker HR series H0 metering valve


15 turns or revolution and a Cv of 0.0004.
Note Parker valves allow full shutoff of the valve; most others advise against and are not intended for that.


Local quote 4/10/2003:  $104.  Must be ordered from the factory.


I tried to buy the Parker HR. It looks great, doesn't it? Unfortunately, buying one is an uphill battle. Parker has actually only made three types of these valves, and if you don't order that exact configuration, you get a tooling quote along with a minimum buy and a 12 week delivery. So I went back through the distributor to find out which ones were available, and got a quote of $104 each, if memory serves. This all took about a month of back and forth…”



2)      Second choice:  Parker HR series H1 metering valve
15 turns of revolution and a Cv of 0.007.
Note Parker valves allow full shutoff of the valve; most others advise against and are not intended for that.
"20 psi into it and I I open it up about 3 turns to
achieve 1 bubble/sec."
See Dan Dixon "More CO2 injection stuff" or search within the link on the quote:

Local quote 4/10/2003:  $104.  Must be ordered from the factory.  NOTE:  If same

Price as the H0 why not get the H0???????

3)                         Third choice and a close option to #2: Swagelok “S”-series
Swagelok Brass Very Fine Metering Valve - B-SS4  - $47.60)

(Note:  That Nupro is a brand name for Swagelok.  The two valves are the same.)
(Scroll down to and click on “Catalog Information”. Then click on “Metering Valves – complete catalog” for very detailed information.)


10 turns of revolution and a max Cv of 0.004


“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.”



“I can say that the Swagelok S has a control rate of 1 bubble/second/turn”


One user uses a B-405-3 insert to connect aquarium tubing directly into the valve.

See p.52 of catalog:






4)      Fabco NV-55  - $27 this is the one sold by Dave Gomberg


Dave has sold over 500 co2 systems!!!!


See his posting on metering valves:



5)      Fifth choice – and a distant fifth:  Clippard MNV-4K2 – approx $10.10 from local distributor
Max Cv of .004 and 7-8 turns of revolution.
Can be purchased from M3, Aquabotanic, Florida Driftwood and others.
My only complaint is that even with only 8 lbs pressure, the adjustment controls are not very fine - e.g. small turns of the adjusting know result in big changes in gas volume.  I wish it were finer.
I used a Clippard for years, and I would never have called it "good". I found it was "adequate", and after adjustment it did an adequate job..... Without buying a real metering valve, you won't find a better, inexpensive needle valve for this job.”

Other Valves



6)      HokeHoke Series 1000 metering valves

Micro-mite 1600 series


Max Cv of 0.008   - 13 turns of revolution


I have one of the Hoke valves you mentioned, and love it.  I find the

quality and control it gives me much better than my girlfriend's Nupro.

However, they don't cost $100.  I got mine at an industrial valve supplier in Bellingham, WA, for $40.”



7)      Swagelok – “M” - series – B-4MG2 - $38.40


(Note:  That Nupro is a brand name for Swagelok.  The two valves are the same.)


“We have one by NuPro (model B-4MG2) that cost $35 and is superb.”


“We have used one by NuPro (model B-4MG2, $35) that works extremely well.”


“I installed my Swagelok B-4MG2  series valve in series with my single stage regulator tonight and was "disappointed".  The valve is oversized, so it is twisted way down on the seat…”


“The S series is the finest and probably what you want.  The M series is the next one up and also will work.  One turn of a M series is about 8 turns on the S series.”



“I have one by NuPro (model B-4MG2) that cost S$60.85 and is superb, state of the art stuff. Another worth-every-penny-investment.”



8)      SMC – Specialty Manufacturing – Standard Needle Valves

(Click on red “Information” box for a pdf file of more specifications)


Cv of 0.1

They offer an optional - 6.5 turns of revolution -  valve.  This is the valve that FishVet offers.



9)      Noshok  102MFB


Can be purchased from Custom Aquatics:




It's got a huge solid brass knob which makes adjustments easy. I can easily get less than a bubble a second which is all the adjustment I need.  Regulator pressure is at 24 lbs………

It appears that my satisfaction with the Noshok valve was short lived. For some reason, today I started getting an erratic bubble flow. Output pressure remains the same so it has to be the needle valve



10)  Fabco-Air



11)  Nupro

(Note:  That Nupro is a brand name for Swagelok.  The valves are the same.)


See Swagelok listings for more information.


12)  AquaMedic Regulator with built in needle valve


“I also have an Aqua Medic regulator with a built in needle valve and when I take my hand off the knob the bubble rate changes”



13)  Home Depot “Cheapo”







I tried it and couldn’t make it work.






14)  ARO  -now Ingersol-Rand ARO or IR-ARO

a.      N01 and N02


Apparently the N01 and N02 have been discontinued


“The ARO Model NO1 valve is obsolete, but there are replacements:

ARO Model FO1, NPT size 1/8", Grainger Stock No. 6ZC07, $8.43

ARO Model F02, NPT size 1/4", Grainger StocK No. 6ZC08, $11.30 “



 “It seems like a lot of people are having trouble with their ARO needle valves.  The valves cannot be closed completely enough to allow for good control over the flowrate.”


“I was not too happy with the ARO valves and found it a little difficult to adjust for the application.”



b.      F01


“Even though it received iffy reviews I purchased an ARO FO1, part number 6ZCO7 from Graingers for $11.84. This valve was unable to reduce the flow of CO2 to a suitable level at any output pressure from the regulator. I tried everything from 100 psi to less than 1 psi.”



New Valves


  1. Tunze   #7077/2 "fine adjustment valve"  $11.00


Thread about valve sensitivity/adjustability



This valve may be the best kept secret for co2 regulation.


I really do not have this sort of information.  This regulator is adapted
from an Italian made hospital Oxygen regulator and is quite accurate.  I can
only say that I am not impressed with the clipper as it is rather fragile
and temper mental, this is much more heavy duty.  The valve can fully shut
off the flow.  You set a working pressure with a coarse valve and then your
needle valve bubble count.  It is designed for use with a Calcium Reactor
which requires far more precise control than a planted aquarium.  I use them
myself on my plant tank and I have also used the Marine Depot deluxe as well
the Dupla regulators and find this unit superior to both.  In regards to
turns, it has a big adjustment knob and to go from 1-2 bps probably takes
1/4turn.  This does depend on working pressure though- we recommend 2bar.


----- Original Message -----
From: <BobAlston9>
To: <>
Sent: Sunday, April 20, 2003 9:11 PM
Subject: Tunze #7077/2 fine adjustment needle valve

> Can you sent me specs on your needle valve?  I am interested in comparing
> to alternatives from Parker, Swagelok and clippard.
> A graph of the Cv at various valve openings would be valuable?
> How many "turns of revolution"?
> Can the valve fully shut off the flow?
> My application is CO2 injection into a planted tank.  I am looking for a
> valve that will give me more adjustment latitude that the Clippard I now
> have.  I would like something that allows going from 1 bubble every two
> seconds to 1 per second to 1.5 per second - say over three turns of
> revolution with 15 psi pressure.
> So what can you tell me?
> Bob Alston



Web site/news group references for more information


Nice explanation of various valves – Nupro, Swagelok S and M series




“The double-cross pattern (Fig. 6) comprises two needle valves in series. It provides the same service as the single straight-through valve but with much better control of low flow rates.”

This statement leads me to believe that putting needle/metering valves in series should provide more fine adjustment.  The valve referenced is a Swagelok valve that is actually two metering valves in one device.  Quite expensive – approx $200.


Author’s search for a needle valve, ultimately using a RC aircraft valve


Further information to the author in response to an e-mail I sent:

I run about 9-10 lbs pressure from the regulator. The needle valve goes from 0 flow to about 1 bubble/sec in two clicks or so. One more click gives about 3-5 bubbles/sec. A little fiddling gives a setting in between. The metal U that provides the click setting rotates and is secured with a nut so it can be adjusted.

Bottom line is that the valve provides adequate regulation  in the range desired for aquarium plants. However, if for some reason you want more precision go for the Parker valves listed on the page.

If you use the valve check for leaks around the threads and if found wrap the threads with teflon tape.

Good luck

Andy G


I have read your web site and original posting multiple time.  However, what
I have not been able to find is what level of precision the recommended
aircraft valve provides.  For example at 20 lbs pressure out of the
regulator (or pick a pressure level):

What is the minimum level of flow, bubbles per minute, that the valve will

How many turns, clicks, etc to get to 1 bubble per second - e.g. how fine is
level of control?

How many turns, clicks, etc to get from 1 bubble per second to 2 bubbles per

Thank you!




Nupro Valve FAQ



Parker HR Metering Valve information

See posting by Bruno Fernandes – “Metering Valves – CO2”




Cv requirements and Co2 gas volume per day calculations




Dave Gomberg’s APD Newsletter posting