Oil & Fuel Fuel Tank drain?

[TonyC]

I'm finally getting ready to put in a refueling tank with an electric pump. One of my neighbors showed me something the other day that I've not seen, nor have I read about it in our forums on refueling. He mounts his tank at a very slight angle and puts a petcock on the bottom of the low side. Every 4 to 6 months he opens it up which he did for me. Sure enough, you could easily see dirty water coming out for 4 or 5 seconds then nice pink fuel. Obviously the specific gravity carries the water to the bottom and slides it to the back of the tank. I've not heard of anyone using a drain like this. Has anyone else?

 

[DKinWA]

I've always seen them on commercially manufactured tanks, but can't say that about home made ones. The demonstration you saw is also the reason pump manufactures recommend you not put the intake of the pump directly on the bottom of the tank. The intake on my pump is a good 3 inches off the bottom of the tank so I don't run the crud through the pump and filter. Draining the water off a couple times a year is really good advice. I'd rather take the 5 minutes to do that than repairing the damage the water and other crud can do to a diesel.

 

[Big_A]

What would it hurt? I am wondering what a little water would do to a Diesel engine. I remember when I was in the Air Force that they actually ran water with the jet fuel on the KC 135's (re-fuelers, flying gas tanks) to gain extra horse power on take offs. I understand the reason for draining the line and I'm not condoning not doing it as much as just wondering what damage can or will that small amount of water do to the engine?

Hey Tony,
My land is in Pedlar Mills off of 130, I'm sure we have chewed the same dirt so to speak.

 

[Bird]

TonyC, I've noticed a number of people recommend keeping the pump pickup inches above the bottom of the tank, as DKinWA said, so they won't pick up trash or water that settled to the bottom. And every time I see that, I wonder if they have some way to drain it off or whether they just leave it and hope it never gets deep enough to get to the pump pickup point. Personally, I think your neighbor has exactly the right idea.

 

[DKinWA]

I'm afraid I can't explain all the issues, but my cousin is a diesel mechanic and he explained a couple of them too me. Actually I think he was giving me some advice to cut down on the number of times I had to ask him for help working on my equipment /forums/images/graemlins/laugh.gif The first issue was one of water being a bit more abrasive on injector nozzles than diesel and can mess up the spray pattern on the newer ones. There's also the issue of compressability of water vs diesel. Too much water in the cylinder won't allow it to compress like it should so something else (like a rod) gives instead. I know theres lots of other issues, but I'm definitely not a diesel mechanic and can't say what they are with authority. For all I know, what I said above my not be completely accurate. So..... let's hear from folks that really know the answer!

 

[TonyC]

Thanks, Bird, and I think you are right. It probably is a good idea. I am about ready to go ahead with this tank but now I have to back up a bit and get a drain in there. Oh well, it will be there forever and be helpful in the long run.

 

[Bob999]

<font color="red">What would it hurt? I am wondering what a little water would do to a Diesel engine. </font>

Direct injection diesels use a very high precision, high pressure fuel pump to operate the injection system. My understanding is that this pump is suseptible to damage if it ingests water.

 

[zuiko]

Sounds like a good idea. I assume he is using a round tank. Seems like if you were using a rectangular tank there wouldn't be one low point (unless you made it a corner, in which case you wouldn't be able to put a drain there).

 

[Hambone]

Water in fuel.

Water will freeze in winter. Cause fuel to jell quicker. Water promotes bacteria growth in fuel whick clogs up filters. Water promotes rust in the system. Rust will plug filters, cause corrosion in pump, injectors ect ect ect..

Water bad Fuel good.