What Fuel Line to use

[vonjet]

What is the best flexible fuel line to use? I need some line without fittings I need 1/4" line that will go on 1/4" aluminum lines with hose clamps.

[robjohnson]

I'm going to go ahead and assume that this isn't for actual fuel use on an airplane (or even a lawn mower). If this is for actual fuel use, there are several issues with your config, but let's assume you are wanting to do something else with 1/4" aluminum line joined to flexible hose.

Depending on the content of the line, you could use silicone tubing from Spruce. I used it in my pitot system to join aluminum hard line (pitot heat sink) to nyloseal tubing. Worked great.

If you are thinking of some other fluid that is flammable and/or inside of the cabin, you may want to reconsider the transition and hose clamp idea. There are better choices that are not expensive.

[vonjet]

This is for fuel. I should mention its for a Lancair. The fuel transfer from the wings to the Header tank, which is the main tank. The plans have always called for fuel lines to attach to the header tank feeds with hose clamps. There is about 2 feet of this line in the cockpit. Its a stupid design but I dont know how else to do it. The aluminum lines coming out of my header tank are too short to put a flare and b nut on them. Unless I can have a fitting welded on to the aluminum tubing.

[frankh]

I can only burned at the stake once so I might as well..

In my old Zenair Zodiac I had hose clamps everywhere..not one of them ever failed in 500 hours and the new oners have not reported any problems..The Yaks from Russia are also covered in hose clamps..They work Ok but they are not as bullet proof as what we normally use.

I would not use them for high pressure but up to 10psi I am comfortable with them.

Here is what i would do..You have a 1/4 or 3/8ths piece of tube coming out of the header tank right?

Go to the hardware store and buy a copper compression fitting of the same size.

Slip the cap end over the tube towards the tank and tighten the fitting.

remove the fitting and the compression ring is still firmly attached to the tube.

Now take a Dremel or whatever and cut the cap lengthwise so you can remove it without damaging the tube or tank...quite easy.

Slip the rubber hose (yes from your autoparts store) onto the tube and over the compression fitting...Use a hose clamp in the tank side of the compression ring.

The tube will never pull off because the hose clamp won't slide over the bump that is the compression ring.

Use firesleeve over the rubber hose and hose clamp.

There you go a very solid connection...And of course someone will start whining about how the copper ring and the alu tube are not compatible..well use a little grease and it will be air tight. I used this method for 500 hours and they all looked perfect at every annual.

Frank

[frankh]

I was talking about doing this on the HOT side of the firewall..for the other side delete the firesleeve.

If you want to run solid 3003 tubing then just use my method to connect the ends.

really it will work fine...If your worried about an accident i would argue this method is probably less likely to fail than a flare fitting.

Lets hope we never have to find out though..

[chaskuss]

Originally Posted by frankh

snipped
Go to the hardware store and buy a copper compression fitting of the same size.

Slip the cap end over the tube towards the tank and tighten the fitting.

remove the fitting and the compression ring is still firmly attached to the tube.

Now take a Dremel or whatever and cut the cap lengthwise so you can remove it without damaging the tube or tank...quite easy.

snipped

Frank

The proper name for the round barrel which will stay on your fuel line (as advised by Frank) is a ferrule. Might as well use the proper terminology for this stuff. Saves embarrassment at Ace Hardware or Home Depot.

If you plan to use rubber fuel line, I would suggest asking for rubber hose rated for fuel injection use (good for 60 psi). You don't need the pressure rating, but my experience (owner of an auto repair shop) is that the fuel injection hose lasts MUCH longer than the cheaper "carburetor" (ie low pressure) hose. The carburetor hose tends to dry out after a few years exposure to fuel. It then starts to crack (leaking fuel in the cabin is not something to be desired). You can also increase the security of your hose installation by using two instead of one hose clamp, at each joint.
Charlie Kuss

[frankh]

Try being into this stuff AND being English..I've gotten past my embarrassment a long time ago..

Hose clamps are called Jubilee clips where i come from would you believe..

Frank

[David-aviator]

Originally Posted by frankh

Try being into this stuff AND being English..I've gotten past my embarrassment a long time ago..

Hose clamps are called Jubilee clips where i come from would you believe..

Frank

Jubilee clips? That's about as descriptive as OETIKER. ala, Hans Oetiker mechanical workshop in Horgen, Switzerland, 1942.

I don't know about Jubilee clips but the later are about as bullet proof as any clamp can be with high pressure hose and injection systems. I am using them with Airtex pumps because the pumps do not have AN fittings but 5.16" hose attachments.

There are millions of autos out there with high pressure systems using this technology. They are very reliable. I changed the hose after 4 years but it probably was a waste of time. The hose seemed very serviceable and the clamps had to be destroyed to get them off.

[vonjet]

Rather than use a Ferrule the plans called for adding a slight flare to the tube then slip the hose over this flare. The previous builder did this. Should I expect this to be as good as a ferrule and slide the hose over it and use 2 hose clamps to secure?


Thanks for all the help.

Bryan

[David-aviator]

Originally Posted by vonjet

Rather than use a Ferrule the plans called for adding a slight flare to the tube then slip the hose over this flare. The previous builder did this. Should I expect this to be as good as a ferrule and slide the hose over it and use 2 hose clamps to secure?


Thanks for all the help.

Bryan

There is a better way to go from hose to tube. MSC has a AN6 37 degree fitting with a barbed hose attachment. If you are interested, I can look up the part number, I've got it somewhere in my stuff. I bought several a few years back.