Hydraulic tubing

[ArTrvlr]

I'm with Flusher on the flareless fittings, and have used the ones he references on the DHH site. But if you look at page 2 under JIC 37deg fittings on the same site you will find "Convert-a-flare" fittings that I find work just as well as the "flareless" fittings Flusher references, are somewhat cheaper, and require fewer adapters since they attach the tube directly to the JIC male flare. When I first used them a few years back I was concerned that that would leak because the joint that seals the ferrule to the tube is a narrow crimp. But after heavy use they are holding up fine.

Farmerford, I have never saw the "convert-a-flare" before, but have used the regular flareless fittings recommended by Flusher, and I never had a problem with them either. They are great for repairing factory tubes that have rubber hoses crimped directly onto the tube. I used to use a combination flareless/field installable (reusable) fitting to repair power steering hoses on forklifts. Anyway, my question is, do the convert-a-flare nut and sleeve just slip over a tube, then tighten onto a 37 degree male fitting? That appears to be how it works, but sometime (ok, most times) I am a little slow to catch on.

scarlo101, back to your original question and your decision to go with single flares: My 2 cents on the flaring is if you want to single flare at 37 degrees, the best way is to use a short nut and reinforcing sleeve like item 318 and 319 shown on that same page 2 of 37 deg. fittings at DHH. Beyond that I believe the life of a flare depends a lot on how well the tube is mounted and the proper flex loop in the hose attached to it. Cut down on the vibration it is subject to by a firm mounting and make sure the hose doesn't pull or push on the connection as the cylinder moves and it will live longer, no matter how you flare it.
jp

 

[Egon]

Web site for tubing ratings:
http://www.air-way.com/pdfs/spres.pdf


Web site for fittings:

Parker tube fittings | Hydraulic House

 

[Farmerford]

jp:

Yep, they just slip on and tighten. The sleeve has a female flare on one end (thin, but from experience satisfactory) and a narrow circumferential ridge inside the tube that bites into the tube when the nut compresses the sleeve. Further turning of the nut presses the female flared end of the sleeve (and now captive tube) against the male flare. Like the flareless fittings, the tube end needs to be fairly square and free of burrs. Once the tube is ready, it is as simple as holding the tube fully into the fitting and tightening the nut.