T&T: Diesel Fuel system design

[Larry N. Brown]

Mark,

If you have high speed, I can send you some pics of the fuel control panel I 
designed and had installed. I had the tanks built with separate engine fuel 
suction and return lines and fuel polishing/transfer/priming suction and 
return lines. It's based on 3/8" SS Aeroquip braided lines-- think of the 
gearwell of a jet-- and fittings.

I can feed any engine/genset from any tank and return to any of the 4 tanks. 
8 x 5 way valves. Ditto the fuel transfer/polishing/priming system. 
Machinery fuel supply intakes are 3/4" above tank bottom; 
transfer/polishing/bleeding are 1/4" above bottom. I use a Gulf Coast filter 
F-1 for polishing. When I polish-- tank suction and return to same tank-- I 
use a simple on/off switch. When I transfer-- tank suction and return to a 
different tank-- I use a spring powered 1 hour timer to prevent fuel spills. 
The Walbro 6802 transfers 43 GPH so I take a WAG and set the timer 
accordingly.

My hydraulic steering, propane and RO watermaker high pressure systems use 
45d SAE. Fuel is 37.5d JIC. This gives more surface area for contact. 
Never've seen an air bubble or a fuel leak.

Each main engine and the genset have 2 x Racor 500's, plumbed in so I can 
switch them out underway if the vacuum gets high and change out the filter 
at anchor. I use 30m filters because the Floscan FF transducers require no 
smaller to prevent "bounces". The F-1-- also with vac gauge-- strains down 
to < 1 micron. Racor bowls always contain cherry cider fuel.

Regards,

Larry and Teri
M/V Cigano, 47' Prairie Sundeck Cruiser
Lying: Covington, LA
N 30 26.7
W 90 07.1










> Greetings.  This has probably already been covered in years past, but
> scanning the archives appears to be a chore unless someone would suggest 
> how
> to do a global search on the various monthly archive files.
>
>
>
> I'm rebuilding an engine room from scratch on a 56' steel trawler (circa
> 1955).  I've spec'd out Racor filters and the ESI polishing system and 
> will
> have several manifolds sending fuel from one of assorted fuel tanks to the
> various fuel 'users' (main engine, gen set, furnace), and again with their
> 'return' lines.
>
>
>
> My question:
>
> What would be the ideal fittings and hose types I should use?  Should I 
> hard
> pipe the fuel lines, except for the last little length to the engines?  If
> so, should this be in copper, stainless?
>
>
>
> For fittings, what type do you recommend?  Any 'makes' preferred over
> others?  Is 37 SIC preferred over 45 SAE.or something else completely? 
> Are
> these even the preferred terms?
>
>
>
> Basically I've got the various items to connect, but need help with what 
> to
> connect them with.
>
>
>
> Thanks in advance,
>
> Mark