Fuel vents

[Liambennett]

Hi all,
I’m looking at upgrading the fuel vents and filters on my boat.
Currently the vent is sitting on the deck, the filler is also fitted flush to the deck.
I was hoping to replace and raise the vent to prevent water entering the tank.
Any suggestions?

 

[PierreR]

Hi all,
I’m looking at upgrading the fuel vents and filters on my boat.
Currently the vent is sitting on the deck, the filler is also fitted flush to the deck.
I was hoping to replace and raise the vent to prevent water entering the tank.
Any suggestions?

Wha wha wha what? I don't believe I have ever encountered a fuel vent that vented above the deck level, especially one where water could just run into the tank. Fuel vents are usually high above the water line but below the deck level. Fuel vapors are heavier than air and could sink to the bilge of a boat if vented above the deck level causing an explosion hazard.

 

[rslifkin]

Fuel vapors are heavier than air and could sink to the bilge of a boat if vented above the deck level causing an explosion hazard.

That's an issue for gasoline tanks, but not for diesel. With diesel, the vent needs to be placed anywhere that will allow air exchange and also prevent water from getting into the vent.

 

[Liambennett]

I agree ! The vents are sitting on the deck, which is the top of the fuel tank.
I was planning to remove the vent and attach some stainless tube and run it up the side of the cabin, the attach a new type of vent to the line and protect it with a
clam shell cover.

 

[Flatswing]

Wha wha wha what? I don't believe I have ever encountered a fuel vent that vented above the deck level, especially one where water could just run into the tank. Fuel vents are usually high above the water line but below the deck level. Fuel vapors are heavier than air and could sink to the bilge of a boat if vented above the deck level causing an explosion hazard.

Not entirely accurate: Probably correct for gasoline installations. For diesel trawlers, quite common to have fuel tank vents above the deck mounted on the inside of bulwarks. It is done deliberately so that one can see fuel spit out onto a diaper or other catch device when filling tank without dumping fuel overboard unknowingly. My DeFever is set up that way. Others can be above the deck but on the outer hull.

 

[jgwinks]

Not entirely accurate: Probably correct for gasoline installations. For diesel trawlers, quite common to have fuel tank vents above the deck mounted on the inside of bulwarks. It is done deliberately so that one can see fuel spit out onto a diaper or other catch device when filling tank without dumping fuel overboard unknowingly. My DeFever is set up that way. Others can be above the deck but on the outer hull.

The vents on my Concorde are in the hull sides about 18 inches below the fuel fills. That almost guarantees you spill fuel in the water, the first indication you get that you're getting full is fuel squirting out the vent. I put in vent whistles to prevent that. The sound is annoying but stops when the fuel level reaches the whistle, about a foot below the vent outlet. Every other boat I've owned had the vent above the fill, I never spilled fuel with those.

 

[PierreR]

I jumped the gun a bit. No mention of diesel in the first post.