Pressurized Portable Marine Fuel Tanks

Mark Riechers

(c) Portable marine fuel tanks and associated fuel-system components must meet the following requirements: (1) They must be self-sealing (without any manual vents) when not attached to the engines. The tanks may not vent to the atmosphere when attached to an engine. (2) They must remain sealed up to a positive pressure of 34.5 kPa (5.0 psig); however, they may contain air inlets that open when there is a vacuum pressure inside the tank.

EPA Regulation §(1060.105 (c))effective 01 Jan 2010

Current Design

35kPa

EPA Regulation §(1060.105 (c))

Portable Tank Design Changes

-2kPa

Diurnal Pump Intake

FR

FR

FR

Wall of tank provides reactionary force to draw volume into the tank.(Tank wall is functioning as a pump diaphragm/spring)

Cool air

Diurnal Pump Exhaust

FR

FR

FR

Wall of tank provides reactionary force to expel liquid from tank.(Tank wall is functioning as a pump diaphragm/spring)

If hose or engine leak… Pumping Cycle Continues

until tank is empty

Tilted Engine Applications

Dynamic “Trailering” Overflow Test

Determine Maximum Dynamic Inlet PressureRef. Vapor Separator

(Optimax)

CombinedTilt and Turn

Worst-Case Turn

1) Position test unit at 70° tilt and 30° turn.

2) Route clear vent hose to container for overflow capture

3) Fill float bowl completely full (overflow into vent hose)

4) Accelerate assembly per respective value above

5) Apply pressure, monitor overflow for “pop-off” value

Rough Road

Testing

Transom Vertical Motion Time History, 25 MPH, RR XING

101 102 103 104 105102 103 104 105 106101 102 102 103 103 104 104 105 105 106

s

0

-5

5

-4

-2

2

g

103.5 103.8

Time Boat Transom Acceleration:+Z

101.00 106.00Linears

101.0 102.0 103.0 104.0 105.0101.5 102.5 103.5 104.5 105.5101.3 101.8 102.3 102.8 103.3 103.8 104.3 104.8 105.3 105.8

s

0

-50

-40

-30

-20

-10

10

20

30

40

mm

103.5 103.8

44.4

-56.0Time Boat Transom Displacement:+Z

Rough Road Results

Portable Fuel Tank

Rough Road Conclusions1. 100 mm of transom displacement

2. Visible Leakage from Carburetor at 7kPa (1psi)