Hello everyone,

I am working on an air system modification to allow restricted air out of the down line to minimze the slam down while also using a check valve so the cylinder gets full air when going up (bypassing the restrictor) and going in through the check valve.

I have 4 mm festo check valves, but with air in each side there is free flow from both ends.

Are the black and blue festos only able to work as check valves with fluid?

I tried this on some of the older tan/orange valves that came with my jetcats and they work properly, I just dont like them as much since they seemed to leak/lock when I used to use them for propane...

Any thoughts are appreciated, thanks.

Dave

There are two types of Festo check valves. One is a "one way" valve and the other only closes when you remove the tubing from one end. You need the first type but probably have the second.

Dave, Gordon had this exact problem with his Jaguar (Jag-ooh-ah). He combed the earth searching for a solution and ordered millions of dollars worth (not too far from the truth) of trial valves seeking a solution. Alas! He he found a valve that was adjustably restricted one way, full flow the other. He even set up a wind tunnel to check the under carriage action using this, wondrous new valve.

All kidding aside, it seemed to be a brilliant solution. I'm sure he'll see this thread and comment. If he doesn't I'll call him and have him get the info to you.

http://www.festo-didactic.com/int-en...i4xMDg3LjY5NTc

Cost was about $23 each, IIRC, ordered directly from Festo.

Air is restricted when flowing in the direction of the arrows ; unrestricted in the reverse direction.

you guys are awesome- thanks!

Dave

Gordon,

I looked on that site and that valves looks great. That particular model looks like it is for 4mm. I could not find my way around the site well enough to see if they had it in 3mm.

Would you happen to know?

I will try again, but I could not get to a page that indicated whether it came in another size or not.

If it makes you feel any better, I have already bought Ts, restrictors etc....I would much rather have this valve though, looks easier and far fewer and a better connection.

Thanks again,
Dave

You're welcome - hope the valve works for you as well as it has for me.

BTW, Sideshow Bob is exaggerating:

1) I didn't actually buy millions of dollars worth of parts in trying to get my gear to work - only about $550 Got some cool Eurokit stuff from Italy etc, but in the end it was the Festo that was the most important part of the solution.

2) I didn't actually build a real wind tunnel to test with - simply rigged up a leaf-blower at full throttle to blow against the main gear as I retracted them forward against the airflow. Seems to work quite well.

Gordon

*gasp*

To keep it simple in Festo product there's only one model of 'check' valve. It has an aluminum body. (SMC makes a plastic bodied check valve that's just as good IMO) The other valve you're referring to is a self closing union fitting. They are easy to mix up with each other since the symbols are quite similar. Basically if you want one-way flow all the time, and its a FESTO product, its gotta be an aluminum housing. On the other hand, if you want a fitting for a UAT fill port that closes as soon as you disconnect the fill line, its the plastic body self closing fitting.

The 4mm check valve's part number is: 153462 / H-QS-4
The 4mm self closing union fitting's part number is: 153439 / QSK-4

Both are available for a minimum hose diameter of 4mm according to the catalogues.

Kelly

Sorry Dave - missed your above post since you posted that about the same time I posted my earlier reply.

IIRC, the valve does come in other sizes. I found a useful page on the Festo site earlier, but can't find it right now. For the time being, http://www.globalspec.com/datasheets/846/Festo seems to suggest that the part # you may need is 193965. See also http://www.festo.com/net/no_no/downl...nfo_224_en.pdf page 59

Note that Festo has 2 ways of identifying parts - a purely numeric one (like the 193965 one above), and also an alphanumeric one (e.g. GR-QS-3 in this case).

Hope that helps,

Gordon

So a "one way valve" is not really a one way valve. How could I have not known that all these years of using them? Kind of like finding out there is no Tooth Fairy. I guess I've always used them for air start connections or fill valves of some sort so never noticed they didn't work in an in-line installation.

I'm glad you brought this up Dave because I was about to try that same gear air by-pass technique.

Craig

hmm .. how do you spell that Tim Allen uuuuhhhhgggg? sound?

I'm confused. I have seen the innards of several check valves (though admittedly not a Festo one...). There is a small metal ball that seats in a funnel shaped gland, held down by a spring. When the pressure on the "out" port is greater than the pressure on the "in" port by enough to un-compress the spring, the ball unseats and fluid or gas flows. I can't think how this would be any different in an inline application .. but of course it's the pressure difference that matters not the absolute pressure.

Dave

Craig,

This idea works and keeps those big gear from slamming down - at least in the shop without 60 mph air on them... I tried it with a circuit I made but this Festo seems like a much simpler solution. I am going to order a few especially if I can find them in 3mm.

Dave

Dave - looks like Peter from Altecare has the 3mm version on his site : http://www.altecare.com/festo.htm and search for "Festo 3mm Control Valve" on that page. I think that is the one-way flow controlled version like my 4mm one is. You can shoot Peter an email via the contact info on his site (or shoot him a PM - his RCU id is EICAS) and he will tell you for sure. Peter is a great guy to deal with BTW.

Gordon

Thanks for checking on this - I sent him an email.

Dave

This thread came just at the right time, I ordered a Festo fitting check valve from Troy buil models ( excellent service by the way [8D] )and other stuff with it, I was thinking this was the one way Festo fitting valve that was like the ones you get with your turbine install package but that is not the case and this thread confirmed that.

The Festo check valve will allow the fluid or gas to flow both ways if you insert a line on both ends, disconect the correct line and now the check valve is working by not allowing the fluid or gas to scape.
The Festo one way valve with lines on both ends allows fluid or gas to travel one way only, this is the valve fitting that we get with the install package for our turbines and it's used for the Propane in line to the Prop can.

The valve that Gordon mention is a nice one 'cause you can regulate the amount of gas/air/fluid at any time.

Now I understand thanks again to all of you guys and RCU where we always find the answers.