Weld-On beadlock after crimping?

JWilliams on Thu July 17, 2014 3:29 PM

I've got a leaking high pressure line (R-134a) after the dryer that is 10' long and has multiple bends. There's a short length of barrier hose near the dryer, with a beadlock #6 female O-ring connector on it, and it's that hose that's leaking. After the one foot length of leaking hose, there's another 9' of 3/8" steel tubing winding around the engine compartment before passing through the firewall to the evaporator. It's extremely difficult to remove that hose system due to all the tubing bends and length, so I want to cut off the steel tubing/leaking hose and replace with hose from the cut off tubing to the dryer.

My problem is how to connect to the cut steel tubing. Most people recommend that I not use a compression fitting with R-134a. One shop suggests making up a hose that has the same beadlock #6 female O-ring connector on it to connect to the dryer at one end and a weld-on 3/8 beadlock fitting at the other end. Then they suggest I silver solder/braze the connector onto the cut steel tubing after the hose is made up. I have room to make the braze, but I'm worried about the heating needed to braze after the hose is already crimped on. Won't the heat damage the barrier hose? All the weld-on fittings I can find are very short, so there's not much room for a good heatsink. I don't have room to get the crimper in after brazing, so I can't do the crimping after the brazing.

I'd like to weld on a male insert connector to the steel tubing, then put female O-ring connectors on both ends of the hose. That way the hose isn't exposed to heat during brazing/silver soldering, but I can't seem to find a weld-on male connector that the female beadlock would connect to.

I've also considered trying to flare the steel tubing, and using a flare connector on the barrier hose, but again, I can't seem to find the correct fitting. Plus, I've never flared steel tubing with my tools - only aluminum and copper.

Any suggestions on how to deal with this?

Thanks a lot!

Dougflas on Thu July 17, 2014 9:04 PM

lok-ring tool

bohica2xo on Thu July 17, 2014 10:07 PM

Swagelok fitting.

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"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Cussboy on Fri July 18, 2014 10:56 AM

Quote
Originally posted by: bohica2xo
Swagelok fitting.

Agree, SwageLok only. We use SwageLok at work for hydrogen and helium, much smaller molecules than refrigerant. SwageLok come in different metals, match to your line, and in standard and metric sizes.

bohica2xo on Fri July 18, 2014 9:28 PM

To provide a little more detail, swagelok fittings need to match the tube material. If you have a Steel line that is 3/8" OD as described this would be the fitting:

Swagelok fitting

Locate an accessible straight section of that tube, and cut it. Then install the double ended compression fitting. At that point, you can remove the line segment with the failed rubber hose, and make appropriate repairs - with no underhood torch work.

The fitting may be disassembled & reassembled without affecting the seal integrity. As Cussboy pointed out, they are used for helium at pressures over 2,000 psi without leaks.

B

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

JWilliams on Mon July 21, 2014 9:25 AM

Thank you for the recommendations. I really appreciate the replies. I'll go with Swagelok.

Dougflas on Mon July 21, 2014 1:45 PM

yes. I remembered the name incorrectly but you have the correct info.