Fuel Pickup Size Depth And Material

[Rustic Charm]

I have a 170 L keel tank. It has a 3/8 copper tube to the forward of the tank. The current tube sits about 300mm from the bottom so there is a lot of diesel not used. The tank has three inbuilt baffles.

I'm moving the pick up back where it will pick up from the deepest part of the tank.

Is 5/16 tubing ok to use instead of the 3/8th which seems a bit too big.

Also, how close to the bottom should the tube pick up?

[colemj]

300mm seems like an awful long distance - what shape is your tank? Unless that 300mm gap is in a very narrow deep "V' part of the tank (basically, a sediment sump), you must easily be leaving half your fuel unavailable.

On ours, the pickup is a 1/2" ID tube ending in a bevel cut and sitting <1" above the bottom of the tank.

You don't want to go too small with the tube because it can easily be clogged.

Mark

[Delancey]

Originally Posted by Rustic Charm

Is 5/16 tubing ok to use instead of the 3/8th which seems a bit too big?

Refer to the engine specifications to determine the correct diameter for the fuel supply and return line sizes. What kind of engine do you have?

[a64pilot]

I'd go big on the pickup if you can, West Marine actually sold the ones I put it, aluminum fittings, with plastic tubes pressed in, you cut the tube length to fit, main engine I took right to the bottom of the tank, cut on a 45 of course.
There are two theories, one says leave the pickup tube off the bottom that way you don't pick up the water and dirt, second is put it right on the bottom and pick up the water and dirt when they first appear, don't let them build up. First works if you have a sump drain, I don't.
Generator I left several inches off the bottom, theory being you can't get stupid and burn all the fuel with the genny, I've seen an RV do just that.

I initially made my generator pickup out of copper tube, soldering it into a brass fitting, but as I have an aluminum tank, that worried me and I replaced it ASAP.

[NahanniV]

Opinions vary, here are mine:

- 3/8" is not too big.
- draw from the bottom of the tank; Collect contaminants in the filter, not the bottom of the tank where the amount can become unmanageable. The sludge in the bottom of a tank is most likely to get stirred up in rough conditions.
-I formed the vertical pickup into a spring like coil at the bottom and it sits right on the bottom of my tank.

Cheers,
JM.

[model 10]

Does your return line use the same tube? You can use fuel return as a percolator if it's a different line.

[Cheechako]

5/16 should be fine. What's your engine burn....1/2 gallon an hour?
You're a long way off the bottom of the tank, but why move it back to where the junk accumulates? I guess if you are going to leave it a foot off the bottom it doesn't matter....

[Rustic Charm]

Originally Posted by Delancey

Refer to the engine specifications to determine the correct diameter for the fuel supply and return line sizes. What kind of engine do you have?

VP 2003 T - the fuel lines are standard 5/16.

[Rustic Charm]

Originally Posted by a64pilot

I'd go big on the pickup if you can, West Marine actually sold the ones I put it, aluminum fittings, with plastic tubes pressed in, you cut the tube length to fit, main engine I took right to the bottom of the tank, cut on a 45 of course.
There are two theories, one says leave the pickup tube off the bottom that way you don't pick up the water and dirt, second is put it right on the bottom and pick up the water and dirt when they first appear, don't let them build up. First works if you have a sump drain, I don't.
Generator I left several inches off the bottom, theory being you can't get stupid and burn all the fuel with the genny, I've seen an RV do just that.

I initially made my generator pickup out of copper tube, soldering it into a brass fitting, but as I have an aluminum tank, that worried me and I replaced it ASAP.

Yep, that's why I'm moving it back this time to collect the muck that accumulates. I'd rather change filters than stall when I'm in rough weather and need it not to fail.

[Rustic Charm]

Originally Posted by Guy

Does your return line use the same tube? You can use fuel return as a percolator if it's a different line.

Yes, an entirely different return line and it comes back into the top of the tank.

[seabreez]

If your pickup is 3/8" keep it to that size and make it out of steel to prevent breaking with vibration. Have it as close as you can to the bottom and cut the end off at 60 degrees angle. This will keep the junk out. The debris is going to the filter and eventually you will have clean fuel, no water and will travel farther between fuel ups... Roger

[seabreez]

3/8 " is fine. Steel is very good and cut the end 60 degrees and have it go to the bottom. While you are at this a water separator/filter... Roger

[Wotname]

Originally Posted by Rustic Charm

……….

Is 5/16 tubing ok to use instead of the 3/8th which seems a bit too big.

…...

No such thing as "too big" when it comes to fuel pick up.

While both sizes will work, big is better

[hzcruiser]

Originally Posted by Rustic Charm

I have a 170 L keel tank.

I'm moving the pick up back where it will pick up from the deepest part of the tank.

Also, how close to the bottom should the tube pick up?

Moving the pick up sounds like a lot of effort and I would think about alternatives.

The first question is when was the last time the tank was cleaned? If it's been more than two years there might be a fair bit of gunk at the bottom and if you move the pick up back and extend it you might use up a dozen filter cartridges before the engine runs again.

Last year I cleaned my tanks (after maybe 10+ years) when they were both less than half full. Through the inspection port I lowered a long copper rod connected to a bigger fuel pump and from there to an old 10" water filter housing with a 25 micron pleaded(!) paper filter (otherwise they'll clog within minutes) and transferring the polished diesel to the other tank until I got everything out. Then the same on the other tank before I topped both of them up again.

A small trick helped me get (hopefully all) of the dirt from behind the baffles out: I left about 20cm of fuel at the bottom and redirected the pump outlet hose back into the same tank but stuck the hose through the baffle to rinse the far side of it.

It took me a full two days just changing the paper filters (I think I used up 4 of the 10" cartridges) and disassembling and cleaning the diaphragm pump head about 10 times until I got about 2-3kg of gunk out of each 250l tank!

And yes, I tried to put the pump after the paper filter but the suction wasn't strong enough...

Now that task is on my annual maintenance list but I won't empty the whole tank, just sucking the dirt from the bottom with the copper rod until the diesel fuel before the filter looks clean again.

[Uncle Bob]

Originally Posted by Rustic Charm

Yep, that's why I'm moving it back this time to collect the muck that accumulates. I'd rather change filters than stall when I'm in rough weather and need it not to fail.

Hi I can relate to this, I installed a sedimenter to each fuel line prior to the primary filter, now water and any sediment collect there and the filters last sooo much longer.
Since I went down this road I have had no more problems (touch wood)