Diesel breather regurgitates

[tolhurstorganic]

My Pinky Ketch has twin diesel tanks made to fit from Tex Tanks total capacity 300l,each tank has a separate 40mm filler pipe via a deck filler. The 16mm breathers from tanks are teed into one 16mm pipe terminating in a no smell filter and finally exiting through a breather nipple situated 700mm higher than the deck filler. The vent pipe rises all the way to the filter. Whenever I fill up with fuel a small amount, presumably froth, finds its way out of the breather nipple, this is contaminating the n s filter and is a potential pollution hazard. I am considering fitting a whistle to the vent pipe to enable a more controlled fill.
My question is do I need a separate vent pipe from each tank rather than the shared one I have now? Any other possibilities? I have considered installing an air/fuel separator to the vent line, anybody tried this?

 

[sarabande]

it's probably the size of the breather pipe causing the 'froth' or foam to rise all the way up to the filter.

You have the choice of

1 extending the filler pipe down to almost the bottom of the tank so that much less froth is created (by the diesel falling into the tank). If you can't get into the tank easily then pass a 15mm line down the pipe and the diesel will cling to this.

2 making the breather pipes wider so that the froth can disperse before reaching the filter

3 using red diesel which doesn't froth quite so much

4 change your supplier, as some diesels have anti-frothing agents built in

5 buy some E900 anti-foaming agent, and DIY.



http://www.chm.bris.ac.uk/webprojects2001/anderson/antifoamingagents.htm

and some discussion on a landrover forum

http://www.vegetableoildiesel.co.uk/forum/viewthread.php?tid=1553