On Sep 19, 7:53 am, Warren wrote:
Currently copper pipes are used for all diesel fuel lines.

I have a concern regarding their use between boat mounted fittings and
engine mounted fittings. Will the vibration of the engine cause an
eventual failure of these lines? These lines are about 2 feet long
and, from memory, there are three of them. All the lines are quarter
inch in size.

The copper pipe you refer to sounds more like it's copper tubing.
Copper tubing, for an application like this, is typically the same
grade they use in A/C systems, it's fairly soft and flexable, so it
holds up pretty well under vibration. I have to admitt, I prefer heavy
hoses for this kind of application, but the copper tubing is much less
expensive and easier to install. You don't have to measure out the
lengths and then go to a supplier to make up the hose. For copper, all
you need is a small pipe cutter and a flaring tool.

John