Double flare for rigid diesel fuel line

[Sailingfun]

I'm on the process to replace the old rigid diesel line (in very bad condition) with new copper rigid ones.
Did anybody know if I need to double flare the ends?
I know on brake car lines, double flare is mandatory.
Thank you in advance!

 

[Loren Beach]

For some reason I always believed that our rigid fuel lines (from high pressure pump to the injectors) were steel.
(?)

 

[Chris Mc.]

For some reason I always believed that our rigid fuel lines (from high pressure pump to the injectors) were steel.
(?)

Ditto.

 

[David Grimm]

They can be purchased from Kubota for a fraction of the cost of marine stores. I replaced mine. Gives a new look to the old girl.

However if you are talking about the copper line from the tank to the lift pump its time to replace it with USCG approved rubber line.

 

[Sailingfun]

Yes, it's fir replace lines between tank and engine. Rigid copper lines still been legal and way less expensive than hoses.

 

[Loren Beach]

Yes, it's fir replace lines between tank and engine. Rigid copper lines still been legal and way less expensive than hoses.

Interesting that it's still "legal"..... I know that our surveyor does not like it.
Our '88 boat was built with a copper supply line and a reinforced hose return line. I replaced all of the fuel system hoses/lines over a decade ago. The new hose, presuming you also use USCG approved hose, is multilayered and certified for both supply and return.
Lots easier to install, also,
The OEM copper in our boat looked like it had been pulled thru, from the tank, by an over-caffeinated person and was really bent & beat up.

I would advise, if anyone were to ask, to change over to hose. Double clamp all ends. In comparison to copper flare fittings, which I have done in a past life, the hose solution is lots easier. I do not know how the cost comes out. I was concerned with longevity and ease of installation. Also, that copper needs extra protection against chafe and especially vibration -- much easier to protect hose where it passes thru compartments and bulkheads.

Isn't "boat yoga" Fun!

 

[Sailingfun]

$4 hose... $30 for 50' good copper line. Do the math.
At the trade is not about you like or not. It's legal or not. Period. Rigid line are the standart at commercial. I never found too much hose at commercial boats.

 

[Kenneth K]

I replaced all of my fuel line hoses (hoses wear out) but none of my copper lines (between tank and fuel pump). The usual complaint I hear about solid lines is that they can be crushed, and then are prone split open--a good reason not to use solid lines in exposed areas. All my solid lines are tucked into secure corners so I've never worried about them. I'm planning to get another 30 years out of them.

 

[David Grimm]

My copper line was worn thrugh and leaking out of site under the floor. Lots of vibraion and moisture under there. Rubber line will most likely out last me.