Thread: Compression Fittings for steel fuel line

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I just wanted to get these fittings out there incase anyone else is wanting to run steel lines. I know aluminum is the norm but I am nervous using aluminum when I know fuel quality is for shit and the percentage of ethanol is cause for worry. I will be running 1/2" diameter by .035 wall steel hydraulic tubing for all of the van's fuel and return lines.
I will be using YOR-LOK compression fittings from McMaster Carr. They go from the 1/2" steel line to any size pipe thread you could need. I will be using the 3/8th female NPT and running 3/8th NPT male to -8 AN adapters to get from the pump and out to the engine.
McMaster-Carr
These are designed to work with gasoline and have dual ferrules to provide a leak-free seal. No worries running these, they'll work great and they are not expensive.
Mark

How do you plan to use he -8 adapters?????????????? You do not want to be mixing AN fittings with other types of fittings as angles/threads don't mix---------

Not an issue Jerry, the classic aluminum AN fittings come with a 3/8th's NPT. That matches the pipe thread in the steel Yor-Lok and adapt that to any AN thread you want to use. In my case I will be using the -8's. I will get pics and part numbers when I get all of the fittings gathered up. I am in process on the McMaster Carr order and will be ordering the NPT to -8 adapters from Jegs this weekend.
Mark

I am very familiar with the AN stuff--wrked for airline since 1961 and racing since I invented the wheel!!!!!!!!!!!

I read the MaMaster Carr pages about the fittings and no where did any text or photo/diagram show or dscuss AN fittings!!!!!!!

And it won't... The Yor-Lok is an adapter. It goes from 1/2" steel tube to a female 3/8th in. NPT. The -8 aluminum fitting is an adapter also with a male 3/8th NPT that threads into the Yor-Lok.
The Yor_lok adapter I am using is this one.
McMaster-Carr

The -8 aluminum adapter I am using is this one:
Earl's AT981608 Earl's Ano-Tuff Adapter Fittings

Mark

Oh, I see now--your using an adapter to an adapter so you don't have to flare the tube??

You could also just slide the hose over the tube and use hose clamps-----




Take a look at Earl's fittings Number EAR165008-------------------AN-8 male to 1/2 tube

I could be all wrong here – but I’ve pretty much gone to braided stainless steel hose and AN fitting on everything. I have had hard metallic lines in brake and fuel applications and when they rust they are an absolute bugger to work on. It may be a bit more expensive, but it lasts forever and has no issues with vibration or stress. The rating is typically 500PSI plus and the operating temperature is -40 to 300 degrees F. The manufacturing process takes all liquids into account and most all of them have a statement similar to this:

“Stainless steel hose consists of a synthetic-nitrile inner tube with a partial stainless steel reinforcement inner braid. On top of that, we add a heavy-duty, protective, full stainless steel braid on the outside, making it exceptionally lightweight, flexible, and durable. Even better, our hose is designed to handle gasoline, oil, or coolant.”

Tight connections, lots of versatility, lasts a lifetime and looks great.

My two cents.
Glenn

Originally Posted by jerry clayton

Oh, I see now--your using an adapter to an adapter so you don't have to flare the tube??
You could also just slide the hose over the tube and use hose clamps-----
Take a look at Earl's fittings Number EAR165008-------------------AN-8 male to 1/2 tube

I agree that the single Earl's fitting is a preferred method to the two fittings together, but using the two fittings is no different from hooking two AN female hoses together with an AN male/male union as opposed to making up a longer hose. You have three fittings for the joint vs two. I wouldn't worry a minute with the fittings Mark picked being secure. Now using the 1/2" steel hard line vs the braided stainless Glenn suggests? I'd lean toward the hose, simply because the line is going to tend to rust over time, regardless how you may coat it.

I use stainless hard line-----------

And--------the fewer joints, the less chances of a leak----leaking fluids are not only dangerous in the fact that you lose the system, but have increased fire risk and possibly loss of control from fluids under tires-----------

Originally Posted by jerry clayton

I use stainless hard line-----------

And--------the fewer joints, the less chances of a leak----leaking fluids are not only dangerous in the fact that you lose the system, but have increased fire risk and possibly loss of control from fluids under tires-----------

Yeah, you probably only had a hundred or so joints just like that on the aircraft you flew, Jerry. Every bulkhead connector has three fittings, essentially identical to what Mark described. Two better than three? Sure, no argument that fewer joints makes less chance to leak, but a properly tightened joint is not a risk for leaks, or at least they weren't when I QA'd and signed off the work on the planes I checked.

Mark, thanks for the details on the fittings. Looking forward to the next installment of photo's on the van!!

so hows the tree house coming?

Originally Posted by jerry clayton

so hows the tree house coming?

Not to hijack Mark's thread, but rafters are up, waiting for me to put up the barn roofing.

Thanks guys, you always get me to think about what I am doing and I like that. A lot. I decided on the steel hardline because it is easier to work with then the stainless and I have had bad experience with the braided hose. I just don't like to run it the full length of a vehicle. Short lengths at the pump and carb are okay.
As far as rust is concerned, the steel line will get routed, the ends assembled, everything cleaned and then powder coated. I am not worried about rust. The van will never see any conditions to have to worry about it. It will definetly be kept clean and the lines will be run in channels we are going to build into the old rails so it will be well protected. I really doubt there will be any issues with it.
Mark

Originally Posted by astroracer

.... As far as rust is concerned, the steel line will get routed, the ends assembled, everything cleaned and then powder coated. I am not worried about rust. Mark

Mark,
Can you help me understand at what point you plan to powder coat the lines? Are you saying you'll mount the tube fittings, then powder coat the fittings along with the line, figuring that you'll never need to break them loose again?

That is correct Roger. The lines will be fully assembled when they are coated. I will fully clean the inside of the tubes, assemble the steel adapter fittings, pressure test the assembly, plug the ends and have them coated. Should work well.
Mark