Asking for Checkvalve information

All,

I would like to setup a helium/argon mix which I saw in one of Jody's WT&T videos. He sets-up a simple "Y" connection with two flow regulators and uses checkvalves to prevent back-flow into the tanks.

Although I have an OA setup (used mainly for heat treating) I don't use checkvalves nor am I familiar with them. I was under the impression that each valve was specific to Oxy or Acy... Which kind should be used for a mixing setup -and does anyone know of some at a reasonable price?

Thanks

Ray

PS: Sorry for always asking questions but not contributing much in return but, in most areas of wedling, I'm in learning mode...

Jackru might be able to help out as he is adding helium.

I found http://www.generant.com/hpcv.shtml and this http://www.hylokusa.com/products/val...ef-valves.aspx

Also this one. http://www.oxycheck.com.au/catalogue...&subcategory=1 for gas.

You would need to order the reverse flow check valves by your line thread size and the ones in that video were mounted right after the flowmeter before the Western 411-Y

http://www.westernenterprises.com/enterprises/check_valves.php

http://www.harrisproductsgroup.com/en/Products/Equipment/Accessories/Torch/Check-Valves.aspx

http://victortechnologies.com/IM_Uploads/doclib_4108_Victor%20Safety%20Information%20121-125,%20134_65-2007.pdf

Parweld makes the chrome plated brass ones with the hose barb fitting attatched.

http://www.wholesaleweldingsupplies....0check%20valve

these work good inline plastic check valves . i use these for my hydrogen generators when i made them http://www.ebay.com/itm/Aquarium-Ant...item4cfcbc8550Attachment 7768 plus there green to match the welder lol

Finally, an honest ebay ad; "random delivery" :D

Quote:

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Originally Posted by Rodsmachineshop

these work good inline plastic check valves . i use these for my hydrogen generators when i made them http://www.ebay.com/itm/Aquarium-Ant...item4cfcbc8550Attachment 7768 plus there green to match the welder lol

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Cheap but not sure they're going to match the color of my new welder.

I have a He-Ar "Y" setup without the checkvalves, and haven't experienced any problems.

Get two flowmeters that have compatible output pressures (e.g. the same pressure ideally... and one simple way to ensure this is to use two identical brand & model flowmeters), and also close off the tank valves when they are not in use, and you should be fine without them.

Here's some pictures of my setup: (apologies for double-posting, the time limit for editing the last post seems to be awfully short!)
Attachment 7787

I made up the lower brass fitting shown in the following picture by TIG welding:
Attachment 7786

Honesty don't see why you need check valves . there no way a few pounds of pressure shielding gas is going to back feed into a tank that's 100 pounds pressure or higher . also cheaper why not just use a plastic y fitting only like a dollar or cheaper Attachment 7788

Quote:

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Originally Posted by Rodsmachineshop

Honesty don't see why you need check valves . there no way a few pounds of pressure shielding gas is going to back feed into a tank that's 100 pounds pressure or higher . also cheaper why not just use a plastic y fitting only like a dollar or cheaper

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I believe it's just a precautionary measure to prevent reverse flow damage to the regulators when the welder's electric solenoid valve is closed.

Rod - a plastic Y fitting like you've shown I'm sure would work in a pinch provided you got one with the right diameters, but for durability I'd recommend stainless or brass.

On mine I set it up with a threaded fitting that is the same as on the outlets of my flowmeters, so I can unscrew the hose connecting to the machine, and connect it directly to a flowmeter if I want to remove the Y. Then the removed Y stored compactly, and doesn't waste much hose, since it only has dedicated for its purposes two short lengths of hose, rather than a third longer hose.

As for why Jody uses check valves in his, I believe he told me in an e-mail response to this question (when I asked him a while back) that he did it to prevent losing gas if he forgot to turn off a cylinder valve (which apparently happened to him once over a weekend, and cost him a lot of expensive Helium that he had manifolded together with multiple cylinders.)

that fitting i put up has a 1000 psi burst rate and 750 psi working pressure . i use to hate plastic fitting till i found they are better for not corroding.

Quote:

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Originally Posted by Rodsmachineshop

that fitting i put up has a 1000 psi burst rate and 750 psi working pressure . i use to hate plastic fitting till i found they are better for not corroding.

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Just keep them away from direct sunlight. I use them on coolers and they work good, but one had sun hitting it and it became brittle and broke. Maybe UV spray them.

Quote:

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Originally Posted by Rodsmachineshop

i use to hate plastic fitting till i found they are better for not corroding.

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I don't think corrosion of brass should be much of a factor for an inert gas delivery application. Given the flowmeter itself, tank valve, solenoid, tig torch head, machine inert arc fittings are all commonly brass, you'd have other bigger problems to worry about if using brass in the inert gas delivery system posed a problem.

All,

In case folks are interested, I found and ordered these check valves and Y connector. When they arrive, I'll let everyone know if everything fits properly. I'm uncertain about the Inlet/Outlet orientation of the Y connector so I called Global and they called the manufacturer who claims it should all work. Keep your fingers crossed for me. I didn't get the Western Enterprises 411-Y with shut off valves although Global Industrial has them in stock for 35 bucks. The straight pipes are 17 bucks less and I just don't see why valves are needed at the Y connection.

http://www.globalindustrial.com/p/to...1-y-connection
http://www.globalindustrial.com/p/to...size-9-16-18-1

Ray

PS: I've had an account with Global Industrial for years and like their prices but, their ground shipping/handling is a little high. Fortunately their checkout page gives exact shipping cost before you commit to purchase. They rarely offer good deals on shipping like MSC does but, MSC's overall prices are much higher than Global... Anyhow, Global is one of my preferred sources of stuff -much cheaper than McMaster.

Quick update about the check valves... Sure enough, the Y connector was the wrong gender (despite calling and being assured it was compatible for my purposes). No problem, they're good about returning things and the correct one is on it's way. Aside from that, I ordered 2 of the following flow meters and I like them a lot. Really good price and an added bonus is that the check valves shown in the previous post fit directly to the flow meter. That saves a couple connectors. Just waiting for the Y connector now. When it's all rigged up, I'll post a pic and links to all the correct parts that make it work.

http://www.ebay.com/itm/HTP-Argon-CO...06%26rk%3D1%26

Those regulators appear like a Harris knock-off just wish they hade them with chrome plated brass for that price.

Here's a pic of those HTP regulators (mentioned in this thread) and the check valves (also mentioned earlier). The check valves fit the outlet (9/16" / 18 TPI) and the barbed coupler fits the check valves. Still waiting for the Y connector....

And just for grins, here's a pic of the finished cart with 2 more toolboxes added on the back. They're removable and hang on hooks. The cart serves me well so far.