Fuel Tank Fittings...

[MonacoMama]

Can anyone tell me what the 5 fuel tank fittings are for? (We can come up with these ideas: one feeds the generator, one feeds the engine and the third is an air vent line.)




Here is anotherangle of the 4...

[Steve Ownby]

Two fuel return lines. 1 each for the engine & the genset.

[Mike Canter]

I agree with Steve.

[Diplomat Don]

My understanding is that the diesel engines pump more fuel to the engine than the engine can use, thus the return line. As long as the engine is running in cold weather, fuel keeps getting returned to the tank and keeps the fuel in the tank from freezing.

I may be full of baloney, but that's how it was explained to me.

[Coma]

Do you have Aqua-Hot?

[Our Time]

Correct answers. Fuel return lines. Almost the same as a gas engine that returns to a vapor tank, the diesel returns to the fuel tank. Good question about the Aqua-hot though. Not sure how it feeds.

[Gordon66]

The one in the middle may be the overflow.

[Mike Canter]

The EPA does not usually allow open venting/overflows directly to the atmosphere plus there has to be a roll over safety valve on the vents and overflows just in case. But there is probably a line that is used for a vent there somewhere that goes through some kind of check valve and cannister. All fuel tanks are designed so they cannot be filled to the top so there is room left for expansion and because of the location of the filler neck you cannot fill them all the way so an overflow is not required but like said a vent is required so either the heat expands the contents or air has to be let into the tank as you use the fuel.

[pipedream2]

gas engines have a pressure /vacuum relive on the cap to prevent "solvent"evaporation of gas in the atmosphere......diesels have an open vent ...i have cleared mine of mud dauber nests that plug it and cause vacuum in the tank when driven several times and there is no check valve in line.Not an overflow though....much too small and wrong location......just an atmospheric vent to prevent the tank from collapsing as fuel is used up

[Mike Canter]

On my MH I have a a contained vent system and a rollover check valve. Must be something that was added as time went by.

[Robi.1014]

Interesting Mike. My Dip is the same year as your rig. But my vent is just a tube hanging down.

[Mike Canter]

Hmmmm, maybe my assumption on what I saw was incorrect. maybe I will take another look. I would think they would be the same.

[pipedream2]

Mike
What you have may well be an addition by the previous owner and is a very good idea.....i like it and you got my attention.As i said i have cleaned my vent out several times because mud daubers had plunged it and really didn't know that till i stopped for a fill up and heard the vacuum.luckey enough that i fill the tank at around half or it could in theory calaps the side walls in.Its a PITA to say the least as i have to remove screws that hold the panel down.(not a latch as all the other bays) remove the top of the hose and blow them out
Any way you could post a picture here?Is it near the tank itself??