Installing fuel line for Webasto

[blackrose]

The Webasto installation instructions state that fuel lines must not be run adjacent to heat sources, but I'm finding it difficult to connect the fuel line without going near the exhaust which is already in place fitted by the builder. The exhaust has a 4" dia metal conduit over it but from memory it still got quite hot.

 

I'm replacing an old Eberspacher and the copper fuel line used to run alongside the exhaust so I could do the same thing and connect the final few inches with Seaflow rubber fuel hose (ISO 7840) which is heat resistant up to 80C. However, the Webasto instructions don't say which type of fuel line mustn't be adjacent to the exhaust, so I can only assume it's fuel lines of any type including copper? 

 

Or could I run the Seaflow hose past the exhaust and protect it with some fire-proof conduit?

Edited September 14, 2021 by blackrose

[blackrose]

Could I put the fuel line inside a length of this stuff to protect it from the exhaust?

 

It's about £12/m on eBay

 

[matty40s]

Yes you could.

..but...

Many boat systems go near boat exhausts and I have yet to see one that has caused a directly attributable problem.  If your Eberbastard never had a problem in that location, it is unlikely that the Webasto would be any different.

 

[blackrose]

Ok thanks, I was thinking the same.  Hopefully various inspectors will agree.

Edited September 14, 2021 by blackrose

[David Mack]

A recent thread concluded that copper gas pipes could run through hot zones. Surely the same logic should apply to copper diesel pipes.

[BEngo]

Gas pipes are full of gas.  Diesel pipes are full of liquid.  If the pipe gets hot enough the diesel turns to gas (boils).  Diesel will certainly boil at exhaust temperatures.  This may not matter if there is a small bubble close enough to the burner to vent out, but a big bubble will make it hard to start.

Once lot there should be no problem as the flowing diesel will keep the pipe cool .

 

There is no danger of ignition in the pipe though.

 

I am with matty on this.  If the previous heater worked OK the new one probably will.  A bit of localised glass bandage  wrap of the exhaust ( if not already wrapped) should keep any passing inspectors happy.

 

N

[Jen-in-Wellies]

20 hours ago, blackrose said:

Could I put the fuel line inside a length of this stuff to protect it from the exhaust?

 

It's about £12/m on eBay

 

This sort of stuff does work. A long time ago, I used something similar to this on a car clutch cable that ran close to an exhaust pipe. After a while, the heat would melt a plastic lining inside, causing the cable to bind, making the clutch pedal very stiff to operate. The fibreglass sleeve over the affected region of a replacement cable solved the problem.