Fuel lines... Copper pipe or hose?

S

seafox67

Well-Known Member
Joined
14 Apr 2017
Messages
281
Location
Greenock
Visit site
I've had some adventures dealing with the dreaded bug (fuel) this season so one of my winter projects will be to install a twin pre filter type system so if one clogs up without warning I can quickly switch over to the other clean one.

My current setup up has a 30 cm copper pipe coming out of the tank and into the original pre filter. With the space I have, it will be easier replacing this copper pipe with hose.

Is there any benefit between using either copper pipe or hose for fuel lines?

Cheers
Paul
 
Fuel companies seem to advise against using copper or other yellow metal in contact with diesel, it can cause breakdown and the formation of tar-like stuff.
Metal pipe is of course more fire resistant.

It seems to me that if you have enough water and crud in your tank to block one filter, there is very likely enough to block both.
It's been suggested that the 'spare' filter could draw from higher up the tank.
 
I don’t know if others but for me it is the risk of fire damage with plastic , all around my engine bays are copper
 
Unless you will be subject to 'British Waterways Regulations' I think opinion will suggest hose.
I think the reasons given will be the potential for copper to fracture with vibration and corrosion.
lets see what the experts have to say!
 
Totally agree with the need to fit flexi hose to stop damage because of vibration. Just ensure it is proper Fuel Hose to ISO 8402 (I think or something very similar) with a red stripe.

Oh and double hose clips too.
 
Last edited:
pcatterall said:
Unless you will be subject to 'British Waterways Regulations' I think opinion will suggest hose.
I think the reasons given will be the potential for copper to fracture with vibration and corrosion.
lets see what the experts have to say!
Click to expand...

The vibration sounds a possibility. My current setup has only copper pipe from the tank to the pre filter and then it goes to hose into the engine. I thought it was strange that the original installer didn't use all hose! I'm hoping that I can just change it all to hose because I have plenty when I built my fuel polishing system along with a spare filter.
My idea behind having a duel filter is just to get me to somewhere safe to anchor. I'm single handed and my engine clogged up this year just as I was coming out of the narrows at Kyles of Bute. No wind and a strong current! it would have been handy to be able to quickly switch over to a clean filter and get to some relative safety!
 
Traditionally copper was the norm then braided nylon was used and now fuel specific is the default so perhaps it depends when you started working with it
It would seem that nylon hard or soft has fallen out of favour due to it’s susceptibility to fire and discolouration and rightly so.
Copper was never used for diesel tanks but seemed to cope when used for pipes but modern fuels it would appear not to go with it
So now we have designated flex pipes
 
pcatterall said:
Unless you will be subject to 'British Waterways Regulations' I think opinion will suggest hose.
I think the reasons given will be the potential for copper to fracture with vibration and corrosion.
lets see what the experts have to say!
Click to expand...

The Code permits (in fact some inspectors encourage) the use of flexible hose, provided of course that it is fuel hose and properly marked.
 
This forum really does make me laugh sometimes. :):):):):):)

You can't fit metal pipes to boats because they'll corrode, crack, turn your diesel to tar and make your testicles go black in the night. Hmmm

My boat was built in 1980 and like pretty much all other boats of the era, it has copper fuel lines, not seen any of the above problems yet. Is 40 years to soon ? Should i expect doom and disaster soon ?

That said, If i was installing a new setup, i would use flexible fuel hose these days, it's much quicker and easier to work with.
 
Thank you for everyone's feedback.

It sounds like my 1989 boat started out with copper pipe and then someone changed part of the fuel lines with hose.
I have plenty of the proper hose so it sounds like it will be fine to remove the last of the copper pipe and make the duel pre filter install an easier job.

Cheers
Paul
 
I am in the similar position to the OP in that I am putting together a new fuel system with dual filters.. (see my fuel system woes thread).One of the issues raised by Volvo Penta engineers (the real guys who have dirty hands and actually fix marine engines, as oppossed to head office) when I discussed my problem was that flexible hose can compress under suction and in braided hose manufacturing issues can arise leaving air holes that open at different levels of vacuum.. also tight turns with fuel hose can be difficult.

unless I can find credible alternatives I am going to go with spin on filters, copper pipe brass fittings all mounted on a board with flexible sections joining onto the engine/tank.

I also intend to fit a completly separate pickup and 12v pump and filter that can be pressed into use as a short term solution in an emergency...that will be almost entirely fuel hose with the pump near the tank exit. ( it will be pulled out of a scrap van in my garden)
 
I have used hydraulic hose since the 80s. The engineer offered to demonstrate with a blowtorch that copper would fail quicker than hydraulic. Obviously you have to get it made up with swaged ends.
 
Really not sure why use copper when s/s hydraulic tube and fittings as standard available and as easy to work with as hardened copper
 
Copper and FAME don't like each other, so if you are in the habit of using, for example, forecourt white, then flexible is the preferred choice.
 
penberth3 said:
Now you've mentioned s/s, any problem with ordinary steel tube?
Click to expand...
I use S/S because I had some about but normal hydraulic fittings are plated steel and normally keep well, advantage I find over copper fittings is the range available leads to less joints
 
prv said:
Only that it seems unnecessarily difficult to work with compared to the proper rated fuel hose.

Pete
Click to expand...
Why, ring cutter and spanner although I work with high pressure gauge lines for my day job so like the neatness of solid pipe, I can probably make a section between fuel filters quicker the cutting and crimping flexible and with less joints
 
You must log in or register to reply here.

Share this page

Top