Diesel fuel line: Replace metal with rubber?

[bostonmish]

If the diesel tank is about 3 feet from the motor, any harm in replacing the hard fuel line with marine grade rubber hose?

In my boat (1968 Alberg 37, Perkins 4.108) the fuel tank was replaced in 2002 and the old main and primer fuel lines are sloppily installed and poorly routed. The metal lines weave from the motor to the fuel tank - through two bilge sections.

I'd like to replace with a rubber hose, from the tank to the motor compartment and from there continue with CuNi to the motor connection points.

OK or not, for boat diesel fuel system?

--
Michael

[donradcliffe]

OK with hose rated for fuel use.

[GordMay]

Marine Fuel Line USCG Types: A1 vs B1 [vs A-15/B-15]:
The "A" designator means the hose can be used in enclosed spaces, i.e., it passed a 2.5-minute fire test;
The "B" designator means the hose should be used only in open, above deck spaces, i.e., it has not passed a 2.5-minute fire test.
The numerical suffix indicates the suitability for certain applications:
- the "1" suffix indicates the hose is designed to have fuel in the hose all the time, i.e., it has low (less) permeability;
- the "2" suffix indicates the hose is NOT designed to have fuel in the hose all the time, e.g., used for a tank filler hose; i.e., it has higher (more) permeability;
The USCG safety ratings do not meet the EPA requirements, for fuel line permeation, which shall be less than 15g/m^2/day.
EPA-compliant fuel hose is labelled A1-15 or B1-15 showing the A or B fire rating, and the ultra-low permeation, at 15g/m^2/day.

Hence, I’d recommend using an “A1-15" type non-metallic fuel hose, like Trident Series 365 Barrier Lined A1-15 Marine Fuel Hose
365 ➥ https://tridentmarine.com/product/tr...se-365-series/

[Jammer]

Modern practice in marine and most industrial diesel engine installations is to use rubber hose for the entire run from the tank to the lift pump and filtration. Years ago, hose of sufficient quality for that was unavailable, so builders used metallic lines with rubber connections as needed, with a presumption that the rubber connecting pieces would require periodic replacement.


Any of the A1-rated fuel hoses should work. There are several vendors. It is not a particularly expensive material.

[gonesail]

important to use "below deck" rated fuel hose. it is the strongest and most reliable .. albeit expensive.

[barnakiel]

No problem on low pressure side.


Mind a tube, copper or steel, will be more resistant to damage from chafe - there the hoses go thru bulkheads or simply touch anything that moves or vibrates (from boat movement, hose movement, or engine vibrations).


I also found well done tube fittings leak less vs hose + clamps. If you can have banjos pressed onto the hoses, then this is not a problem thou.


b.

[bostonmish]

Thank you all for the replies!

I'll be looking for the proper grade, below deck hose and be mindful of the potential chaff points.

Cleaning up, rerouting and resecuring everything I find under the floor. Preparing for the future motor swap and bilge clean and paint.

--
Michael