Fuel tank breather & capacity

Yesterday whilst en route for Naples from South of France we stopped in Bonifacio, Corsica for diesel. The tank meter had indicated Zero just before arrival so we added 10 litres to ensure arrival. I understood that the 415 tank had a capacity of 160 litres but it took 170 Litres (without sign of being full) in addition to the 10 litres added earlier. A few hours later there was a smell of fuel inside the boat an some in the bilges in addition to water. The quantity was not great but if course there is more in the moulding between bilges formations.

I'd like three questions answered.

1) What is the capacity of the tank?
2) Is there breather valve for the tank & if so where is it?
3) Is it quite like that the bilge diesel I've found likely to come from an internal breather?

Simon,

I have the magnetic version from Philippi for the fuel tank. It is called TGT line, the height for the 160 ltr tank is 200 mm, TGT 200 has the order number (Bestell-Nr)  6 6011 7080. You need a “GWA” adaptor flange order number 6 6010 9010 as well. This makes it an easy drop in installation. It took me about 15 minutes. You can still use the indicator in the Würth panel.

Edited by Fendant - 20 May 2016 at 10:01

Hello
I cant speak for the 415 but on our 545 build 2010 there is a VETUS SPLACH-STOP installed by Hanse just under the fuel filler cap underdeck.This to prevent overflow on the deck By the filler cap.
. By example : cold fuel from the fuel station mixt with the relative warm fuel in the boattank will expand and the fuelgauge and the fuel nozzle auto stop can not react fast enough.
In this case the small 2 liter reservoir will full up.
This splach stop is placed in to the filler hose and also in to the airbreather hose.
In my case the connection of the breathing hose was not done right and leaking.
In normal condition ( the small reservoir is empty there is no problem) in case of a overfilling the 2 liter of the reservoir will flow back to the tank by the airbreather line and in case there is a leak ,fuel will run inside the bilge ( max 2 lit)

With a strong smell of diesel, two days ago I went bilge diving & found many ares under the floor had fuel in them. Yesterday I borrowed an electric pump & removed nearly 60 litres! I had not overfilled by that amount, maybe 20. The problem lay with the tank inspection cover. Fuel was seeping out under the gasket. The fuel level was up to the tank sensor. The cover bolts were loose so we tightened them & that just made the problem worse. We called in the cavalrymen who pumped out 40 litres of diesel & removed the inspection cover. This has the fuel delivery & return pipes in it. When lifted away the condition of the gasket was terrible, it fell to pieces. The top of the plastic tank with nuts for the plate is badly distorted a& there are dips between each nuts so the tank top around the inspection cover is no longer flat. Thank you Hanse for a nasty plastic tank with no real re inforced area for the inspection cover. The plate was replaced on a bed of Sikaflex 291i as this is fuel safe & tightened. I replaced 20 litres of that removed.

The tank capacity is in excess of 160 but should have the area above the inspection plate occupied with air rather than fuel. Had our I.P. not leaked we would not have had a problem I guess.