EPA Pressurized Portable Fuel Tank Requirements

The Environmental Protection Agency (EPA) will require portable fuel systems that are produced after January 1, 2011 for use with outboard engines to remain fully sealed (pressurized) up to 34.4 kPa (5.0 psi). These tanks may contain the following:

  • An air inlet that opens to allow air to enter as the fuel is drawn out of the tank.
  • An air outlet that opens (vents) to the atmosphere if pressure exceeds 34.4 kPa (5.0 psi).

Fuel Demand Valve (FDV) Requirement

Whenever a pressurized fuel tank is used, a fuel demand valve is required to be installed in the fuel hose between the fuel tank and primer bulb. The fuel demand valve prevents pressurized fuel from entering the engine and causing a fuel system overflow or possible fuel spillage.

The fuel demand valve has a manual release. The manual release can be used (pushed in) to open (bypass) the valve in case of a fuel blockage in the valve.

A - Fuel hose between the fuel tank and primer bulb

B - Manual Release

C - Vent/water drain holes

Mercury Marine's Pressurized Portable Fuel Tank

Mercury Marine has created a new portable pressurized fuel tank that meets the preceding EPA requirements. These fuel tanks are available as an accessory or are provided with certain portable outboard models.

SPECIAL FEATURES OF THE PORTABLE FUEL TANK

  • The fuel tank has a two-way valve which allows air to enter the tank as the fuel is drawn to the engine, and also opens to vent to the atmosphere if internal pressure in the tank exceeds 34.4 kPa (5.0 psi). A hissing noise may be heard as the tank vents to the atmosphere. This is normal.
  • The fuel tank includes a fuel demand valve that prevents pressurized fuel from entering the engine and causing a fuel system overflow or possible fuel spillage.
  • When installing the fuel tank cap, turn the cap to the right until you hear a click. This signals that the fuel cap is fully seated. A built-in device prevents overtightening.
  • The fuel tank has a manual vent screw which should be closed for transportation and open for operation and cap removal.

Since sealed fuel tanks are not openly vented, they will expand and contract as the fuel expands and contracts during heating and cooling cycles of the outside air. This is normal.

REMOVING THE FUEL CAP

A - Fuel Cap

B - Manual vent screw

C - Tab lock

IMPORTANT: contents may be under pressure. Rotate the fuel cap 1/4 turn to relieve pressure before opening.

  1. Open the manual vent screw on top of the fuel cap
  2. Turn the cap until it contacts the tab lock.
  3. Press down on the tab lock. Rotate the fuel cap 1/4 turn to relieve the pressure.
  4. Press down on the tab lock again and remove the cap.

DIRECTIONS FOR USING THE PRESSURIZED PORTABLE FUEL TANK

  1. When installing the fuel tank cap, turn the cap to the right until you hear a click. This signals that the fuel cap is fully seated. A built-in device prevents over-tightening.
  2. Open the manual vent screw on top of the cap for operation and cap removal. Close the manual vent screw for transportation.
  3. For fuel hoses that have quick disconnects, disconnect the fuel line from the engine or fuel tank when not in use.
  4. Follow Filling the Fuel Tank instructions in your Operation, Maintenance and Warranty manual for refueling.

FAQs

Do I need to use a fuel demand valve?
Yes, when the tank is pressurized.

How will I know if I have a pressurized fuel system?
It will be indicated by the tank cap (will ratchet similar to automotive).

Does the fuel demand valve need to be in that position in the fuel line assembly?
No, it can be anywhere as long as it's between the fuel tank and the primer bulb in the fuel line assembly.

If I want to fill the tank, what should I do if I notice the tank is under pressure?
Rotate the fuel cap 1/4 turn to release pressure (see the four-step process above or refer to your Operation, Maintenance and Warranty manual).

Does the fuel demand valve have to be in a certain position (i.e. always facing up) to work?
It will function in any position.

What is the purpose of the holes in the top of the fuel demand valve?
The purpose is for venting the back side of the valve and water drainage away from the fuel demand valve diaphragm; the valve can be opened by depressing valve mechanism through slot on cover (manual over ride).

Is it ok to use 10% ethanol fuel with the fuel demand valve?
Yes

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