Single Flare Fuel Line?

[slikside]

My neighbor, ex mechanic/auto parts type, told me that only a single flare was necessary for fuel lines due to the lower pressures involved. I have a single flare tool, but not the double.

What say you??

[CUSTOM/10]

I agree !

I have even done single flares on brake lines because I didn't have a double flaring tool at the time, and had NO PROBLEMS !!!! I don't recommend it on brake lines, but it can work !

[slikside]

Cool, thanks! Yeah, he said he wouldn't recommend for brakes either, but for fuel....np.

Glad yours worked out for both.

[Longhorn 70]

If you want to do double flair, AutoZone will loan you the tool for free

[Scottcoda]

when I was doing my fuel lines I stopped by a local garage and asked if they could flare it for me, they did it in 2 min and did not charge me for anything

[cool68]

many do not even do a single flair - single is plenty for average motor.

[Steve Cole]

Aircraft use single flare fittings on everything including hydraulic lines operating at 3000 psi.

[truckdude239]

Originally Posted by Steve Cole

Aircraft use single flare fittings on everything including hydraulic lines operating at 3000 psi.

Remind me not to fly..... but they also use different style lines amd flare sizes

[slikside]

Originally Posted by Longhorn 70

If you want to do double flair, AutoZone will loan you the tool for free

Yes, O'reilly's does as well. Just don't want to bother if I don't really need to. Thanks, though. Others may not know this. These stores let you buy (and return for full refund) many specialized single use type tools.

Originally Posted by Scottcoda

when I was doing my fuel lines I stopped by a local garage and asked if they could flare it for me, they did it in 2 min and did not charge me for anything

Right on! That's some good-will type customer service there!

Originally Posted by cool68

many do not even do a single flair - single is plenty for average motor.

Thanks for the confirmation. But how do you get away with no flare at all?? I'm planning on using OE steel tubing. I just don't see how you can seal that with no flare?

Originally Posted by Steve Cole

Aircraft use single flare fittings on everything including hydraulic lines operating at 3000 psi.

Really??

Originally Posted by truckdude239

Remind me not to fly..... but they also use different style lines amd flare sizes

Yeah, I'll try and forget about that one when I go to work next time!!

[colgad]

Single 45 degree flares can crack, do the right thing use a double. Even for low pressure fuel if the fitting leaks you are spraying fuel where you don't want it.
If your in love a single flare then go to a AN style fitting and you can safely use a 37 degree single flare. That's what aircraft industry and the military uses.

[In The Ten Ring]

I am going to double flare mine. I bought a Craftsman kit.

I plan to use Poly Armor from NAPA.

[john]

Originally Posted by colgad

Single 45 degree flares can crack, do the right thing use a double. Even for low pressure fuel if the fitting leaks you are spraying fuel where you don't want it.
If your in love a single flare then go to a AN style fitting and you can safely use a 37 degree single flare. That's what aircraft industry and the military uses.

Agreed, double flares are stronger than single flares.

[burnin oil]

Originally Posted by slikside

Yes, O'reilly's does as well. Just don't want to bother if I don't really need to. Thanks, though. Others may not know this. These stores let you buy (and return for full refund) many specialized single use type tools.

Sometimes this is a good deal but most of the time I end up with a abused tool that only half way works. I end buying a cheap tool from harbor frieght that works better in the end. Use it a couple of times and I end up saving cash from going back to the store to return it. Now the ball joint tool is another ball of wax. The local Azone doesn't care if it comes back broke. I really use my tools but everyone has different needs. I am not rich or a mechanic but have several Snap On tools for a reason.


For a double flare kit I would invest in a quality tool. Cheap ones tend to make crap flares that never seal.

[Fitz]

Originally Posted by colgad

Single 45 degree flares can crack, do the right thing use a double. Even for low pressure fuel if the fitting leaks you are spraying fuel where you don't want it.
If your in love a single flare then go to a AN style fitting and you can safely use a 37 degree single flare. That's what aircraft industry and the military uses.

SAE and ASTM certify 304 stainless joined with 37 degree flares at pressures up to 18,000 PSI.

MIL-SPEC AN fittings match those pressures.

[cool68]

with the low pressure in the line of standard fuel line feeding a carburetor with a good fuel line hose a good wide single or two narrow hose clamps will hold & seal just fine - a single flair is good for added safety and peace of mind.

[cdowns]

absolutly no advatage to a double flair // single flair ihas been just fine for goin on a hundred or so years in the industry for fuel

[slikside]

Thanks for the responses guys. I did "rent" a double flaring tool along with a pipe bender since I did not have a bender myself. And it's the bending that has kicked my a@# so far.
double flares on practice material came out great, but so far haven't done it for real because the learning curve for the pipe bender (poor) has been steep. I'll try to let you all know what happens.

BTW cdowns, this is for a pump to carb hardline. Now I know why I've been running a rubber line all these years!

[burnin oil]

A good tube bender is worth its wieght in gold. The cheap ones work but tend not to do the tight bends well. The biggest thing is to resist bending it with your hands. You can gain a degree or two this way but odds are you will kink it. The other thing I have found is that it is easier to unbend a slight overbend then putting it back in the bender to add a little more. Usually if it goes back into a bender to add a little more you will kink it. I hate bending brake tubing, I find electrical conduit to be alot easier.

[CUSTOM/10]

Bending can be a bit tricky. Especially when it comes down to the last bend, do it wrong and you may have screwed up the whole piece. I've bent miles of tubing. Practice will definitely help. A trick I use when it comes down to the last bend is use a gunner, or a short piece of tubing ( 6 or 8 in ). Stick this gunner in the last fitting, put the piece your bending in place and mark your tubing where the two intersect. Also mark your tube in the direction you want the bend to go. Bend it in the wrong direction, well your starting all over again. There should also be some markings on the bender, if it's 1/2 way decent, for 45% & 90% bends. They have these marks because you use up more tubing for sharper bends. Always keep cut your piece of tube with some extra ! Coming up short on you last bend mean Yes your starting all over again.

Hope this helps some !

Gary

[burnin oil]

Good point on loss. 1/2" EMT electrical conduit losses 4-5"s depending on the bender. I would think brake line would be more like 1-2" for a chunk of 3/8ths.

[CUSTOM/10]

Try this link, if it doesn't work copy and paste it and do a search. Down on page 14 it show you these markings on the bender. There's lots of other good in info in this bending manual !

Gary


http://www.swagelok.com/downloads/We...n/MS-13-43.PDF

[slikside]

haven't had the chance to get back at it yet, but one of the things I'm considering, for one of the sharper bends, is a little heat, as in torch. Any predictions??