How does the fuel tank filler cap vent valve operate?
The vented gas cap is designed to vent small amounts of air into the car gas tank line. The vented gas cap has a one-way release valve that is pressure-activated. After the pressure inside the line equalizes, the pressure valve closes. The valve is set to balance the pressure with the surrounding atmosphere.
Where is the fuel tank vent on a boat?
The fuel tank vent is located on the outside of the boat, normally relatively close to the fill port on the gunwale of the boat. Taking a look on the outside of the hull and seeing if the vent is even there, if it is corroded, broken or upside down. With the hole facing towards the sky allowing water to get into it.
What should I Cover my fuel tank vent with?
If your boat takes a lot of heavy spray and you’re experiencing problems with water in the fuel, consider covering the vent with a clamshell cover. You can get a chrome-plated brass model such as the Perko 2-inch-wide clamshell, a stainless-steel version like the Seafit 2 1/8-inch-wide version, or the ABS-plastic SSI 2 5/8-inch-wide clamshell.
How does a boat fuel tank overflow when filling?
The vent hose should come off of the vent port fitting, facing upward. The hose should make a loop up from the vent and then loop down after that. This ensures that water can not enter into the fuel tank via the vent tube.
Is there a problem with the gas vent on a boat?
Shortly after I had a new fuel tank installed, I discovered a problem — a boat gas tank vent problem. It was difficult to put gas in the tank. The nozzle continually shut down, as if the tank were full, until a gusher of gas spewed from the vent. Then I could fill up just fine.
How does the fuel tank ventilation valve work?
Gasoline expands in volume as it warms up and shrinks in volume as it cools down. The fuel level of your tank changes throughout the day, even if you are not driving it. You cannot put fuel into your tank, unless you can get the air out…and you cannot withdraw fuel from your tank unless you can let air in.
Why does my fuel tank have a hole in it?
Unfortunately, this hole would allow the fuel to splash out when accelerating or turning a corner. If you are running a vent line it is important that the line is ran higher than the highest point on the tank including the fuel filler neck. Also, the vent line cannot have a dip in it where fuel or condensation can get trapped in the line.
What causes gas to come out of the vent?
If fuel becomes trapped in the line your tank will then build pressure or vacuum until there is enough pressure to purge the vent which will cause gas and/or odor to come from the vent line. If enough pressure builds up damage could be caused to your tank.
What does it mean when your gas tank is bulging?
As stated above, bulging gas tanks or fuel line leaks can be an indicator of high vapor pressure in the gas tank or fuel system. Trouble filling your gas tank can also be an indicator. “A slow filling tank is typically a venting issue, a filler neck issue or both,” Justin stated.