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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: grantgoold on October 30, 2008, 06:00:37 AM

Title: Venting fuel tanks
Post by: grantgoold on October 30, 2008, 06:00:37 AM
I have a 50 gallon fuel tank for the genset. I want to make sure the tank is vented. My current cap is clearly marked non-vented. What are you folks doing to vent the tanks?  I see a vented cap or a tank vent used in many marine applications. The tank does not have a built in vent.

Thanks

Grant
Title: Re: Venting fuel tanks
Post by: TomC on October 30, 2008, 06:19:41 AM
Especially if the tank is mounted in a bay, you have to have a tank vent to the outside.  Both for possible overflow and to allow air back inside the tank as the fuel level lowers.  Stay with the non vented cap, but get a vent fitting welded onto the top of the tank (1/4" pipe should be enough).  Good Luck, TomC
Title: Re: Venting fuel tanks
Post by: grantgoold on October 30, 2008, 06:22:31 AM
Tom, can you provide more details on the vent fitting. I have been looking all morning for a vent fitting online. Not sure of what would be required.

Thanks

Grant
Title: Re: Venting fuel tanks
Post by: luvrbus on October 30, 2008, 06:31:06 AM
Grant, a 1/4 inch pipe collar welded into the top of the tank or on you filler pipe and go from there with fitting and a hose make sure it is a couple of inches above the tank which ever way you go, fuel will splash out if not a few inches above the tank most are in the filler neck fwiw the ones on top of the tank work best when filling   good luck
Title: Re: Venting fuel tanks
Post by: artglass on October 30, 2008, 06:37:18 AM
if you go to a farm equipment dealer , preferably a smaller one that might  be family owned you could probably talk them in to finding a vent for the differental  or transmission on a mid 70 or 80 farm tractor  they usually had a 1/2" or 3/4" pipe thread on them , i have used them off of a oliver before.
Kevin
Title: Re: Venting fuel tanks
Post by: grantgoold on October 30, 2008, 06:43:49 AM
I think I get the concept. No special valve or such? Is this a special vent valve that allows air in but no fuel out? Or is this a vent that simply is above the top of the fuel tank for overfill situations and allows air to be "sucked in" when the fuel pump pulls fuel in?  Should I put a filter of somesort on the end of the vent to prevent contaminants from entering the tank?


Grant
Title: Re: Venting fuel tanks
Post by: artglass on October 30, 2008, 06:47:14 AM
IT IS A VENT THAT ALLOWS AIR IN  HAS A CAP ON IT SIMILAR TO A VENT ON A NORMAL DIFFERINTAL AS ON YOUR BUS ONLY IS LARGER, SHOULD KEEP OUT ALL WATER AND OTHER CONTAMENTS
      KEVIN
Title: Re: Venting fuel tanks
Post by: luvrbus on October 30, 2008, 06:52:42 AM
Grant no special valves you could put a screen on the end of the hose it you are worried about any trash, no problem with water it won't flow up hill without pressure the type Art is talking about are design to go on top and work good but always leak a little do like Tom said and vent it outside the bay fuel is nasty and doesn't smell good inside a bus     Good luck
Title: Re: Venting fuel tanks
Post by: Lee Bradley on October 30, 2008, 09:31:11 AM
Grant,
You can find weld-in fittings here http://www.racepartsolutions.com/products.asp?cat=20 (http://www.racepartsolutions.com/products.asp?cat=20)
Title: Re: Venting fuel tanks
Post by: Utahclaimjumper on October 30, 2008, 10:05:48 AM
I would simply vent the "unvented" gap, no welding of the tank needed. A simple hose nipple threaded into the top of the cap and a short piece of small hose will do it.>>>Dan
Title: Re: Venting fuel tanks
Post by: dickegler on October 30, 2008, 05:20:19 PM
Hi,

I don't know what material your tank is made of, but you might consider one of the rubber grommet type fittings used on poly tanks.  I don't think tank material would matter. Drill hole, insert rubber grommet, then push the fitting in, thus expanding the rubber to seal the fitting..   I've seen all size fittings used, might take a little looking to find the right one.  1/4 in hose should be sufficient. Marine or snowmobile applications come to mind. maybe chain saws

Good luck

Dick Egler
Title: Re: Venting fuel tanks
Post by: JackConrad on October 30, 2008, 05:45:28 PM
I always run the vent line from the top of the tank through the floor of the compartment. This insures that any fluid in the vent line from sloshing or overfilling goes on the outside of the compartment.  I usually use 5/16" or 3/8" line (because I have quite a bit of that on hand at my shop).  Jack