PTFE Fuel Hose

[Rob58]

Anyone using the Teflon fuel hose with the integrated firesleeve? This would be Stratoflex 124J or the Aeroquip equivalent. Any downside to this hose for the 4 or 5 fuel related hoses in the engine compartment?

 

[FORANE]

I had a hose that looked exactly like it fail; not sure if it was that manufacturer.
If it is bent too much the teflon hose can kink leaving a weak point. In time the weak point may fail spraying fuel. Personally, I would want a hose made with a separate firesleeve such as the Parker:
https://ph.parker.com/us/en/high-temperature-hose-sleeve-firesleeve

 

[Stewartb]

My API fuel injection has a high temp hose that runs from servo to spider right between #1 and #3 exhaust. It’s an integrated fire sleeve hose and works fine. Away from direct heat at the back of the engine typical stratoflex lines are used. The only one with added fire sleeve is from fuel pump to servo.

 

[bnt83]

The downsides? Cost..

 

[Bell206]

Any downside to this hose for the 4 or 5 fuel related hoses in the engine compartment?

Requires crimped fittings so hose P/N or spec needs to be exact when ordering especially with 2 angle fittings. Bend radius limitations vs rubber hoses is some cases. As mentioned additional cost. It's a bit of overkill on non-turbo recips but have seen them used on TC and E/AB aircraft. The advantage to teflon is there is technically no life limit vs rubber hose.

 

[britanyweel]

great product, but the costs are too much for me. any alternatives?

 

[NordicDave]

Requires crimped fittings so hose P/N or spec needs to be exact when ordering especially with 2 angle fittings. Bend radius limitations vs rubber hoses is some cases. As mentioned additional cost. It's a bit of overkill on non-turbo recips but have seen them used on TC and E/AB aircraft. The advantage to teflon is there is technically no life limit vs rubber hose.

great product, but the costs are too much for me. any alternatives?

As usual @Bell206 had good advice. Teflon hoses are preferred for their durability. Somebody mentioned before kinking of the hose. There are standards and practices to follow for radius bends.

The Teflon hoses with molded/integrated fire sleeves are better products than the rubber hose with a slide on fire sleeve in my opinion. It’s not only a more durable product but more petite in diameter making hose management a little simpler.

having just ordered a complete set of hoses for my turbo set up following an engine overhaul, the cost was really not that much more expensive. Have a look at the hose builder tool on aircraft spruces website. Teflon hoses with integrated fire sleeves are about 20-30% more expensive.

 

[mondtster]

great product, but the costs are too much for me. any alternatives?

In the long run the cost of teflon lined hoses will likely end up less than the rubber hoses and their replacements when performed at appropriate intervals.

 

[Let'sgoflying!]

This is current topic for me; let's talk about life limit on teflon hoses...
If the manufacturer specifies then we have to follow that but when that is lacking - is anyone comfortable leaving these hoses in 20 years?
What is the practical limit, in the absence of specific instruction? (does AC43.13 say anything?)

 

[mondtster]

This is current topic for me; let's talk about life limit on teflon hoses...
If the manufacturer specifies then we have to follow that but when that is lacking - is anyone comfortable leaving these hoses in 20 years?
What is the practical limit, in the absence of specific instruction? (does AC43.13 say anything?)

The teflon hoses are considered lifetime hoses. In the absence of specific replacement instructions, I'd inspect them every year or 100 hours and replace based on condition. I'd also consider replacement at overhaul time if the hoses have been installed for the entire life of the engine.

20 years by itself is nothing; many of us drive cars that are older than that on a regular/daily basis with rubber or plastic hoses that have never been replaced and nobody thinks twice about that, although maybe they should.

 

[Bell206]

but when that is lacking - is anyone comfortable leaving these hoses in 20 years?

From my experience, yes. Have seen some go more than 20 years in certain installations. Most teflon hoses are usually changed due to condition issues: chafing, kinked, corroded fittings if applicable, etc. The main failure cause of teflon hoses in my experience is improper installation.

What is the practical limit, in the absence of specific instruction? (does AC43.13 say anything?)

The practical in-service limit is "on condition" for teflon. All hose usually has storage life limits which should not be applied to "in-service" life limits. There are also some ADs/ALSs that assign teflon hose life limits but mostly due from mechanical issues vs teflon issues. The go to reference in most cases is the hose mfgr. specifications like the one below.
https://www.parker.com/literature/S...ure Static Files/SPD Safety Guide 2010-01.pdf

 

[Let'sgoflying!]

I will be reinstalling an engine (turbo)
that has 13 yo hoses.
Strongly leaning towards replacement due to application.... and some bias I suppose.
They look great.
The consequences of failure though...

 

[Rob58]

I will be reinstalling an engine (turbo)
that has 13 yo hoses.
Strongly leaning towards replacement due to application.... and some bias I suppose.
They look great.
The consequences of failure though...

Hi Dave... as you know I have no turbo, however the idea of a fuel leak in the engine compartment is a source of nagging worry. For less than $700 I can replace every fuel line firewall forward with the Teflon hoses. I just finished the annual on 14V only to find fuel leaking from the fuel control valve. So off to Great Planes for a rebuild. Replacing hoses at 15 years seems like cheap preventive maintenance... and like you say new hoses, new parts just look great and that gives me a good feeling!