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Using pneumatic quick disconnect couplings for liquids? 1

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Vindicit

Mechanical
May 24, 2016
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Looking at brass quick disconnect fittings for fluids and compressed gas. I'm looking for information about using these fittings that are labeled as for "Air" use but use them for water. Is that generally not a good idea? I'm not able to find any information that specifically says no. The quick disconnect fittings for fluid are generally double shut off which I dont need but I dont want full flow sockets either. But these fluid quick disconnect fittings are twice the price as air fittings and spending ~$35 for 1 set of a socket and plug is a bit pricey when you need a dozen of them.

 
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In general the air fittings will have too much restriction to flow to use for fluids except at very low flow rates. Then there is also the matter of seal and material compatibility. Air fittings are often steel with very light surface treatments and not suitable for liquid service.
Many people deliberately use different fittings for every service to minimize the risk of cross connection.
Take a step back and figure out what performance you need.
Single end shutoff, double, none?
What seal material?
What body material?
Pressure and flow ratings?
How does it connect to your system?
By the time you answer these you will have narrowed the list down to just a few choices.


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P.E. Metallurgy, consulting work welcomed
 
Anodized aluminum or plastic may work for you. It depends on your water P, T, and contaminates.

Good Luck,
Latexman
Pats' Pub's Proprietor
 
And every time I disconnect one, I get sprayed in the face.
Not nice with any other of the nastier liquids, hence the double shut off.
Keep the pressure low, even if clean water.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"
 
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