Outrageous Fuel Tank Idea

[Wand]

It's a common experience for fuel problems to emerge in a choppy sea because of the disturbance to the crud at the bottom of the tank.

Which reminds me of an approach a local old salt took to the problem years ago and still swears by it. And that is to run the fuel line from the lowest point in the tank. The idea is that the crud doesn't build up but rather comes through all the time. It just means cleaning your fuel filter more often, but that's nothing. And it means you know the tank is clean and that you'll never strike the problem of your engine cutting out in choppy conditions close by the rocks.

I liked the idea and recently set it up on one of my vessels but haven't had enough time to evaluate yet. But what do others reckon; is it worth some thought?

[zeehag]

folks i know have saved many dollars because they made fuel polishing systems inside their own boats.

[capngeo]

Or....... filter the fuel on the way INTO the tank!

[simonmd]

Ok, forgive me if i'm being daft here but, if the fuel line ISNT in the lowest part of the tank, wouldn't the fuel line run dry before the tank was empty? Surely, if the line is a quarter of the way up for example, then you'd run out of fuel after only useing three quarters of a tank......

[stevensc]

Usually the fuel is taken from a couple of inches off of the bottom of the tank. What I don't understand is why there is not another valve at the lowest point or even a sump to collect water and some of the crud, it could be drained into a can and disposed of.
Steve W.

[delmarrey]

One down fall of your idea!
An outlet at the bottom of the tank is dangerous let alone against the ABYC/USCG advice.

The pickup tubes are to come from the top and stop about 1/2-3/4" from the bottom, don't remember for sure but here's the doc. to read for yourself.
New Boatbuilders Home Page - Fuel Systems

Source: CGD 74-209, 42 FR 5950, Jan. 31, 1977, unless otherwise noted.
Sec. 183.518 Fuel tank openings.
Each opening into the fuel tank must be at or above the topmost surface of the tank.

Sec. 183.556 Plugs and fittings.
a) A fuel system must not have a fitting for draining fuel.

And for Canada http://www.tc.gc.ca/publications/en/...hr/tp1332e.pdf goto page 73

[O.C.Diver]

The fuel tank in my boat has a sump that stickes down 4" below the bottom of the tank and is 4" in diameter. The fuel pick up tube comes down to within 1/4" off the bottom of the sump. There is nothing but fuel in my tank.

The sediment and water from condensation that is normally found in marine fuel tanks, collects in the bowl of my Racor 9000 fuel filter separator.

Ted

[serah]

Aren't fuel tanks supposed to have an angled pick-up at the bottom as well? I thought it helped pick up any crud that does develop down there, and then have it stick in the filter, where it should... or perhaps I'm confused.

[svpresent]

Originally Posted by zeehag

folks i know have saved many dollars because they made fuel polishing systems inside their own boats.

Exactly.
I left the suction line for the engine in its place and added a suction line at the lowest point. It's connected to a 12v fuelpump that, I run it once a month. The pump pushes the fuel through a Delphi 10 micron filter/water seperator back into the tank. Cost me appr. 70 euro's. Deals with the dirt and gets the condensated water out of the fuel so no bacteria (they live in the water and feed off the fuel on the "border" between water and fuel).
Cheers, Len.

[atoll]

a daily tank with a normal domestic water filter element on inlet side works well,and saves a fortune on racor filters.

[simonmd]

Well, on mine the fuel pipe comes out pretty much at the bottom of each tank, certainly not a couple of inches above. Mind you, mine is pretty old and 'industrial'. I've never had any fuel debris problems though.

[Capt Phil]

The bane of many Dock Queens is their lack of use, stagnant fuel tanks half full that invite the growth of all kinds of spooky stuff from algea to ? as well as condensation. A fuel polishing system that clears the fuel of debris whenever the motor is running or as an auxilary system is a great idea but at the vary least a dual racor system with vacuum guages, liberal use of biocides and full tanks to lower the condensation problems all help ensure you don't get surprised by having you engine quit unannounced. As a suggestion to simonmd, I would decommission your bottom egress fuel line and install a pickup about 2" off the tank bottom even though it might not be a requirement in the UK. Good idea for all tanks to have an inspection plate with easy access so you actually see what is in there. Some great ideas on this thread... cheers, Capt Phil

[Sailorman Ed]

Delmarrey - I did not see anything why the fuel pickup had to be 1/2-3/4" off the bottom. And your link said: " Do not use copper tubing. Pure copper is very subject to galvanic corrosion. " My 36 year old SS tank has copper tubing and it seems to be just fine although I did replace it last year when I moved the tank location..and if come off the bottom of the tank - I do not seem to have any problem with water or other growth - any water ends up in my Racor filter. It sure is easier to drain the tank with a bottom drain.

[stillbuilding]

One of the things I regret is that I did not incorporate a sludge-collection bowl/area in my main diesel fuel tanks (integral tank in keel). Would have been good to have a special area which I could suck up thru a dedicated cleaning tube (not draining thru bottom of tank). I have polishing system and pre-load filter but still it would have been helpful I suspect.

[Butler]

I had a small 6 gallon gravity feed day tank in my last boat which had a Yanmar 1GM10. To fill it I opened the lazzarette then the tank cap. Any new fuel was run through a baja filter (as seen in an earlier post). This worked really well and yes it saved on filter elements, no fuel sitting around forever and yet the 6 gallons got me anywhere I needed to go easily.
On my current boat it' a Perkins 4107 and some putz set an 18 gallon tank on a platform bolted in just behind the engine so as to prevent any access to the shaft log or coupling. Looks like another day tank in the lazarette for me.