Metering(needle) valves selection for our CO2 pressurized system

[kevmo911]

Originally Posted by herns

Wow! the price is $125!

Ideal V. is about $85 when I bought it.

Well, the millimite has a slightly lower Cv than the Ideal. And, let's face it, it's Evilbay. Some of the really good stuff is priced like the stuff yardsalers drool over, and some of the real garbage is passed off as gold and precious gems. And, either way, it all depends on what you're looking for.

I have a BM series Swagelok valve that's sold new for $250. And I bought it used for $13 shipped. And, since it might actually be useless for what I need it for, I might just sell it for what I bought it at.

[Bettatail]

sell it to me
I will add another metering valve, to make them inline for fine bubble adjust.
so two metering valves together look GOOD.


Put more metering/needle valves inline, the adjustment is much precise, I am going to give it a try.
I plan to use the SMC AS1000 valves I have, to make them two each group(inline, their inlet/outlet are really easy to connect), so finer adjustment.

[Bettatail]

The pictures of Fujikin and HOKE Milli-mite metering valve.
the shape of handles look similar, who try to copy who?

[Bettatail]

Pictures of swagelok 22 series and bellow 4BMRG metering valves coming soon.

[btimmer92]

Originally Posted by Bettatail

sell it to me
I will add another metering valve, to make them inline for fine bubble adjust.
so two metering valves together look GOOD.


Put more metering/needle valves inline, the adjustment is much precise, I am going to give it a try.
I plan to use the SMC AS1000 valves I have, to make them two each group(inline, their inlet/outlet are really easy to connect), so finer adjustment.

putting two needle valves in conjunction will not make them more precise.

The flow will only be as high as the valve that has the lower flow, kind of like only as strong as the weakest link. Whichever valve is set to a higher flow does nothing, because the flow will always be lower due to the other metering valve.

If you have the second needle valve set more closed than the first, pressure will slowly build up between the two metering valves, until it is the same before and after the first valve. After that, the first valve becomes useless and does nothing to the flow of the system, because the second metering valve is the only limiting factor of the flow

[Bettatail]

Originally Posted by btimmer92

putting two needle valves in conjunction will not make them more precise.

The flow will only be as high as the valve that has the lower flow, kind of like only as strong as the weakest link. Whichever valve is set to a higher flow does nothing, because the flow will always be lower due to the other metering valve.

If you have the second needle valve set more closed than the first, pressure will slowly build up between the two metering valves, until it is the same before and after the first valve. After that, the first valve becomes useless and does nothing to the flow of the system, because the second metering valve is the only limiting factor of the flow

good point, didn't think about that.

do someone know c02 density?
there is a formula for this, when two valves setup reach new equilibrium, the flow volume are the same at both valve, but this volume is always smaller than that the single valve with the same orifice/opening.
I remember density, the orifice(cutting surface area of airway), and pressure difference are key elements, but to make sure, I need the book.

[btimmer92]

example metering valve specs:
metering valve 1: 10 turns from 0bps-100bps
metering valve 2: 10 turns from 0bps-100bps

Let's say that metering valve 1 is set at 10bps

the adjustment span of metering valve 2 is NOT: 10 turns from 0bps-10bps
it is actually 1 turn from 0-10bps, and after 1 turn, it will do nothing.

[btimmer92]

good thought though, it would work if the pressure didn't build up between the two valves, because as we know, flow varies with pressure

Jaggedfury once had the same idea you did, except he was actually telling his customers that this could be done with his paintball neede valves..... :0

[maknwar]

If I had a choice between searching for needle valves like the Fujikin and HOKE Milli-mite vs calling Ideal and getting it in a few days, I would take the Ideal any day. Sure, you might find a good deal some day but the Fujikin and HOKE Milli-mite are not that popular and your going to be looking for a while.

[btimmer92]

I have still not to use anything in my setups except a fabco. I really want to try out an ideal, but they are too expensive for me. I will probably buy a few and build some regs out of them once I sell a regulator and get the necessary cash.

[Bettatail]

Originally Posted by btimmer92

good thought though, it would work if the pressure didn't build up between the two valves, because as we know, flow varies with pressure

Jaggedfury once had the same idea you did, except he was actually telling his customers that this could be done with his paintball neede valves..... :0

the problem is that the input psi is 800, too much, if for some reason the second valve stuck, the space between 1st and 2nd valve will be 800 psi, if this space is plastic air tube but not metal that can withstand 800 psi, it will burst.
so cut off the flow from second valve will cause trouble, and always turn off flow at 1st valve.

[Bettatail]

Originally Posted by maknwar

If I had a choice between searching for needle valves like the Fujikin and HOKE Milli-mite vs calling Ideal and getting it in a few days, I would take the Ideal any day. Sure, you might find a good deal some day but the Fujikin and HOKE Milli-mite are not that popular and your going to be looking for a while.

it is for collection, not for sale

and you can see ideal on flea bay too, just need some luck.
I believe someone here bought 3 or 4 of them, brass, the ideal, at the price lower than the swagelok.

[Bettatail]

Originally Posted by btimmer92

example metering valve specs:
metering valve 1: 10 turns from 0bps-100bps
metering valve 2: 10 turns from 0bps-100bps

Let's say that metering valve 1 is set at 10bps

the adjustment span of metering valve 2 is NOT: 10 turns from 0bps-10bps
it is actually 1 turn from 0-10bps, and after 1 turn, it will do nothing.

HA.
pressure difference.

[btimmer92]

lol lets not start another argument we managed to leave the other one to rest....

[bsmith]

Does anyone know what the model of the Swagelok NV im using is?