Prevent Engine Flooding with a Fuel Demand Valve

fuel demand valve

Have you had problems with your outboard engine flooding lately? If you’ve recently upgraded or replaced your portable fuel tank this year, chances are that that’s the cause. New EPA regulations control portable fuel tank emissions, and your fuel system may not have the proper equipment necessary to keep your engine from flooding.

EPA Regulations & Fuel Tanks

As of January 1, 2011, the EPA requires that all new portable marine fuel tanks follow a zero-emissions policy. To meet these new standards and regulations, fuel tanks can no longer be built as an “open” fuel system. Prior to the change, fuel tanks were manufactured with a fuel filler cap that vented and released gas vapor into the atmosphere. Now that portable fuel tanks must be fully sealed, the gas vapor is unable to vent and has nowhere to escape except to your engine through the fuel line. This builds up pressure within the fuel tank, and puts your engine at risk of flooding.

If you purchased a portable marine fuel tank that was built in 2011, it is likely a closed system and was manufactured to follow these regulations. However, the EPA is allowing all manufacturers and retailers to sell their remaining inventories of open portable fuel tanks. This means that even though you may have bought a portable fuel tank in 2011, it doesn’t necessarily follow the new EPA regulations.

marine portable fuel fdv valve

If your portable fuel tank expands and contracts noticeably with changes in temperature, it is likely that you have a closed fuel system, and the pressure within the system may result in flooding your engine. Opening and closing the fuel tank filler cap releases pressure when refueling, but if you don’t refuel regularly, there is more risk of pressure building up in your tank and flooding the engine. It’s always a good practice to relieve pressure from your fuel tank prior to attaching it to your engine. That helps reduce the chance of any fuel spraying or dripping from the connector as you attach it to the engine.

Fuel Demand Valve

Fortunately, we have developed a product to help protect engines from fuel being forced in to the system causing flooding. New from Attwood is our Fuel Demand Valve (FDV). The FDV installs onto the fuel hose between the fuel tank and primer bulb, and prevents fuel from flowing unless there is demand from the engine. This eliminates excess fuel that would otherwise be forced through the fuel line due to pressure in the tank, and avoids the related flooding and engine failure.

The EPA-certified Attwood Fuel Demand Valve is compatible with all new fuel tanks, no matter the brand. The FDVs are available both individually and as part of Attwood’s fuel line assembly, which includes EPA-compliant hose, primer bulb, and the new Universal Sprayless Connector.

With proper usage of the new closed fuel tanks, not only are you helping your boat run smoothly and helping the environment, you are keeping the fuel where it belongs: in the tank. No one wants to deal with the headache or money loss of a flooded engine! 

Portable Fuel & EPA Resources
epa and fuel tanks

By understanding how the new EPA regulations affect your fuel tank’s performance, you can take the necessary steps to keep your engine working properly.For more information on the new EPA regulations, the potential effects of compliance, and the products that keep you safe and your engine performing, visit the Portable Fuel & EPA Resources section of our website. Help the environment and help keep your fuel where you want it… in your tank!