Eberspacher fuel pipe specification

[Quandary]

MY recently acquired yacht will be kept in the Crinan canal and therefore must comply with the 'Boat Safety Scheme'
The Eber is fed by a thin clear plastic fuel line from a riser in the tank via the pump across the stern to the burner. The installation instructions that came with the D3L'C' specify a kit with 2mm. ID plastic pipe from the tank riser to the pump and then 1.5mm. ID plastic pipe from pump to heater, it cautions that this should not be lengthened or shortened and there is a coil in the middle. These pipes are joined to the fittings with 3.5mm. ID rubber sleeves and hose clips.
This is new to me as in the last installation I used 4mm. OD copper without any obvious problem. This time, on the recommendation of the inspector, I propose to use 2 lengths of 3.5 or 4mm. ID fire resistant rubber hose to ISO7840.
My questions
Does the pipe have to be fire resistant if it does not enter the engine compartment? If not the existing installation is fine.
Is using wider pipe likely to give rise to any problems with the operation of the heater provided it rises steadily to avoid air entrapment?
Is the length of the pipe critical, I need about 4m. ?

 

[pcatterall]

Not sure about the inland waterways regs re copper pipe.
Regarding hose diameter it's really a question about what the pump can draw and pump. The 2mm and 1.5 mm are standard eber dimensions to achieve the max lift and pumping distance. These distances and heights are in the eber manual which you can download. If you are well within those dimensions then using a slightly larger ID should not be an issue.

 

[LittleSister]

I recall reading in the Eber instructions recently that the downside of a wider pipe after the map is that it will take more pumps (and hence 'false starts") before the fuel reaches the heater. My guess is that normally the fuel pipe would be full anyway when you commence a start, and that the mentioned downside is only of relevance when you are first setting up the system or if you have leaks, but I would emphasise I have no practical experience of Ebers.

 

[Quandary]

Butler Technik sell a copper fuel pipe kit which I have ordered, it includes a fuel cock and some clips but seems pricey at around £90. No one locally seems to have copper of such fine bore.

 

[lw395]

I used bigger copper for most of the run. And a small filter. I just used a syringe to prime the piping.
Plenty of 4mm copper tube on ebay.

 

[Quandary]

I used bigger copper for most of the run. And a small filter. I just used a syringe to prime the piping.
Plenty of 4mm copper tube on ebay.

I did that when I fitted an Eber on the boat before last and as you say it worked okay, but this time I decided if I did it 'by the book' it would be one less thing to blame when the Eber goes wrong, which it almost certainly will.

 

[Keith-i]

Butler Technik sell a copper fuel pipe kit which I have ordered, it includes a fuel cock and some clips but seems pricey at around £90. No one locally seems to have copper of such fine bore.

I picked up some small bore copper pipe from a hydraulic company. Normally used for brake hydraulics.