PTFE fuel lines recommended?

I'm with Sean. I think PTFE hose is too expensive for what you get out of it. I just had a friend spend $2500 in hose and that didn't cover other parts or any labor. 

Sean Griffin wrote:

Hi Jeff,

No offence, but the above videos are promoting a product which is completely "over the top" for a non certified, small sport aircraft.

What the owner/maintainer does, regarding hose cost, is entirely at their discretion. If they want to go down the aircraft speciality PTFE hose rout  be sure to have plenty of $$$ on hand.

The result will be aesthetically impressive, will not do much, if anything for your aircrafts performance and arguably will have minimal improvement in safety (in flight fire).

Examples can lead to arguments but I have seen 25 year old Rotax powered aircraft, using good quality automotive fuel hose (rubber), that has been replaced at 5 year intervals, all push on fittings, with not even the hint of a firesleeve, flying quite safely.

Sean,

No offense taken.  I have a 912iS and the fuel pressure is about 44 psi with a lot of return flow.  The OEM fuel lines in the engine compartment were AN-06 braided SS with Teflon liner, and it’s an SLSA so that’s what is required. The product I mentioned is also available with an integrated silicone fire sleeve, which is very well done. 

A couple years back I reconfigured my fuel system to match production changes the manufacturer had had made on newer models, and they sent me a letter of authorization to do so.  I used the TS FlightLines product during that upgrade and was very happy with them. See the attached photo, they are the smaller orange lines.  

I agree with you and Roger, they are overkill for the carbureted 912, and maybe even for the injected engines.  I suggested them because the OP seemed to want something more than basic fuel lines, and to illustrate not all PTFE tubing is suited for use as fuel lines on an aircraft. 

Nice instalation Jeff.

"I have a 912iS and the fuel pressure is about 44 psi with a lot of return flow."

Never had the pleasure of even seeing a Rotax iS, let alone working on one but would speculate that the high pressure part of the system is relativly short.

# The twin/parallel, high pressure pumps delivering high pressure fuel (44 psi?) to an in line filter and then on to the injectors.

# The low pressure system, would be fuel from the tank, to the twin HP pumps & the return of excess fuel, to the tank.

If I am correct, any concerns you have, about suitable HP pipes, should be confined to the system between HP pumps & injectors.

Sean,

You are correct.  In my aircraft the pumps are in a compartment under the cabin floor between the wings.  So the low pressure side is short, and is mostly plumbed with aluminum tubing. There is also aluminum tubing from the pump through the firewall to where the fine filter is located.  So the only place the braided Teflon line is used is the engine compartment, both supply and return.  

Thank you all for your comments and hints regarding my OP. Conductivity, for instance, and whole burning sparks were not on my list at all. 

Whilst I am very keen to save some weight by making the right choice I am prepared to pay a price for weight saving. However, I will not waste the dosh for the sake of wasting it. Over-engineering is not my cup of tea. I do like stylish solutions but in this case it’s not a priority.

Along with the PA12 hoses which were brought in by a friend I’m taking aluminum tubes away from your posts and will consider that as an option for the in-fuselage lines. Underneath the cowling I may end up with rubber.  I’ll let you know.

Happy landings

Peter