The issue with most hose applications is not the actual hose itself, but the hose connections, end fittings, and adapters. The factory duck bill fittings connect to polyethylene tubing and are good for up to 150 psi. The EFI system only produces 50-60 psi...so that is more than enough.
...BUT, you have to connect those hoses. So you need to decide on a connection standard. The automotive aftermarket has adopted a variation of the 37 degree inverted flare swivel coupling that is similar to the old Army-Navy standard. This is called the -AN fitting, and it has proven to be easily serviced using standard hand tools.
You need to get from your tank, to your filter, to your fuel rail using some kind of fittings. Braided Stainless Teflon hose with -AN swivel fittings are the most expensive, easily serviced, provide excellent abrasion resistance, are impervious to all fuels, have a small OD, and can perform over 1,000 PSI.
Avoid fittings, connectors, clamps, and failure points. Keep it simple, accessible, and visible.
Quote (Braided Stainless Teflon hose with -AN swivel fittings are the most expensive, easily serviced, provide excellent abrasion resistance,)"
Just a heads up:
I have found that stainless braided teflon hose has the worst abrasion resistance of the types of hydr hose I've used. Use the "ugly" hydr hose that is black rubberized hose like backhoes, ps lines, industrial equipment use if you want abrasion resistance.
My example is this: the aforementioned hose for p/s, laying vertically flat against a fender.- barely touching it. 1 year the vibration wore through it. Like I said, flat, no edges. Just like laying a hose flat against a glass window.
On all my braided flex hose if it is within an inch of touching anything it is protected with a pc of EFI fuel line slid over it.
Quote (Braided Stainless Teflon hose with -AN swivel fittings are the most expensive, easily serviced, provide excellent abrasion resistance,)"
Just a heads up:
I have found that stainless braided teflon hose has the worst abrasion resistance of the types of hydr hose I've used. Use the "ugly" hydr hose that is black rubberized hose like backhoes, ps lines, industrial equipment use if you want abrasion resistance.
My example is this: the aforementioned hose for p/s, laying vertically flat against a fender.- barely touching it. 1 year the vibration wore through it. Like I said, flat, no edges. Just like laying a hose flat against a glass window.
On all my braided flex hose if it is within an inch of touching anything it is protected with a pc of EFI fuel line slid over it.
Interesting, Brian. I've had the opposite experience. That being the stainless overbraid is the saw, not the sawee (new word). I recently had to r&r an aircraft engine mount because a stainless braided oil line had completely abraded through a tube.
For what it's worth, aircraft fuel lines are required to be static-dissipative. PTFE is an extremely poor conductor, and fuel builds static charge just like rubbing your feet on carpet. So carbon black is added to it when it's made into fuel lines. Aeroquip and Parker make most aircraft fuel hose, but it's very expensive and hard to find. They also make industrial grade static dissipative PTFE hose with stainless overbraid that is compatible with field-installable AN (or more accurately, JIC) fittings. Also hard to find but not as expensive.
I've seen PTFE lined hose with other than stainless overbraid (Kevlar + synthetic rubber jacket comes to mind) but I've been away from that world for so long that I don't recall who/where/when.
Also FWIW, auto manufacturers like PTFE at least in part because it's impervious to alcohol. Not an issue in piston aircraft, but PTFE lined hose is the only type in that market that isn't life-limited.
As for getting to/from a fuel tank, if the tank or sending unit has a typical 3/8" or 5/16" OD metal tube on it, a compression fitting can adapt to pipe thread and then to AN. SwageLok, Parker, etc make them. SwageLok makes a spendy compression fitting that fits 3/8" tube and is -6AN male on the other end, eliminating the need for a second fitting (cue James' comment about keeping it simple).
Odd duck here I guess... guys I was with couldn't believe it either... quote for the day was- - "how in the heck can that braided s/s hose get worn thru against a flat pc of sheet metal"... was what we all wondered.
I believe ya, I just won't ever trust it. More than a few people have asked me why so much of my ss braided hose has chunks of rubber over it... for me it's always been "function over pretty". lol
Just be careful all... in my case 63psi of fuel spraying all over wouldn't be the start of a good story!
Odd duck here I guess... guys I was with couldn't believe it either... quote for the day was- - "how in the heck can that braided s/s hose get worn thru against a flat pc of sheet metal"... was what we all wondered.
I believe ya, I just won't ever trust it. More than a few people have asked me why so much of my ss braided hose has chunks of rubber over it... for me it's always been "function over pretty". lol
Just be careful all... in my case 63psi of fuel spraying all over wouldn't be the start of a good story!
Just so you know, you aren't the only one with pieces of of slit rubber/vinyl/whatever hose over it. Anyplace where I couldn't avoid possible contact with something other than a clamp got that treatment! And much of my engine compartment is plumbed with steel hard line.
I replaced everything with Nicopp. Way cheaper than braided steel, easy to flare if you want AN fittings. If you don't want to flair, compression fittings work fine, or you can use a hose flair with Holley Vapor guard hose to connect. You can bend it by hand. Will hold up to any fuel pressure as it meets SAE Standard J and ISO for brake lines. Mine doesn't look as "clean" because of the vapor guard. but this was done on purpose. The idea was if a pump or filter went dead in the middle of no-where, it would be an easy swap and I'd most likely be able to source the replacement with a nipple rather than A/N fitting.
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This one has always bothered me. If the static charge can accumulate and pin hole a non-conductive PTFE hose, then why would it behave differently in a non-conductive PP or PE hose? Seems to me that any hose with a similar dielectric constant would behave similarly.
I wouldn't have believed it until I was shown evidence of it at a tour of South West Research Institute years ago. Apparently the dielectric constant of PTFE is much higher than other commonly used hose polymers. The fact that all of the others already have carbon black in the mix probably doesn't hurt.
In any case on aircraft at least, even a remote possibility of fuel exiting in the wrong location is scary enough to drive decision making about material choices. Having already lost someone because of a fuel fire.
As for getting to/from a fuel tank, if the tank or sending unit has a typical 3/8" or 5/16" OD metal tube on it, a compression fitting can adapt to pipe thread and then to AN. SwageLok, Parker, etc make them. SwageLok makes a spendy compression fitting that fits 3/8" tube and is -6AN male on the other end, eliminating the need for a second fitting (cue James' comment about keeping it simple).[/QUOTE]
The sending unit does have the typical 3/8” and 5/16” metal tube but the way it comes out of the sending unit at a 90 degree, it doesn’t appear to be much room for any type of fitting other than hose and a clamp. I have never used any AN style fittings, but am pretty confident that any type fitting would not fit this. I will try to post a pic later today.
The sending unit does have the typical 3/8” and 5/16” metal tube but the way it comes out of the sending unit at a 90 degree, it doesn’t appear to be much room for any type of fitting other than hose and a clamp. I have never used any AN style fittings, but am pretty confident that any type fitting would not fit this. I will try to post a pic later today.
I had stock tanks set up that way using Swagelok fittings for years. Easy.
This is the fitting I used, which I also have now on my aftermarket tanks:
https://www.swagelok.com/en/catalog/Product/Detail?part=SS-600-6-6AN