How full can you fill fuel tanks on newer C-Dorys?

[pcg]

I’ve read that EPA rules (that went into effect around 2011/2012) for marine vessels require a fuel system that allows fuel vapors to be captured and also that will work with the newer auto shut-off fuel nozzles. This means that there is a fill limit vent valve on top of the tank that closes before the tank is full, creating a pressure surge that allows the fuel nozzle to shut off. Some have complained online that this substantially limits how full the tank can be filled.

Are the newer C-Dorys required to have this technology? (If there is a carbon canister in the fuel vent line then I’m guessing they do.)

If so, how many gallons of fuel can you actually put into a “25 gallon” tank, in a new C-Dory?

[thataway]

If you want to see the rules as noted by ABYC here.

Generally I have found some C Dorys more difficult to fuel than others, depending on route of both the fill tube and the vent/vent tube. I try and allow for air and vapor venting around the nozzle when filling (This may not be possible in some states like Calif.--I believe Oregon has the same rules-- where there is a closed vapor system when filling tanks). Also Oregon has "no topping off tank" rules, so those, are going to be restrictive. If I was filling a tank in Oregon (and I don't know if you are allowed to do that in a service station or not), I would go very slowly for the last few gallons.(probably not a bad idea anywhere to avoid spills.)

One of the reasons that the C Dory 25 was given two fills, was to allow complete filling of the tank in about the 2004 era. (It is also much more convenient for taking on fuel to have fills on both sides).

Theoretically, you should be able to fill a tank as completely prior to and after the 2011 deadline, if you go slowly enough. The vent valves are 1 PSI.

[pcg]

Here's a video that shows what happens during filling. To save time, start at 0:55. https://www.youtube.com/watch?v=FszARiU_jRI&feature=youtu.be

[Wefings]

The "party line" from tank Mfgs is that you lose 7-8% of the tanks capacity due to the EPA required equip. That is really an issue for the long range fishermen and cruisers . The tanks are supposed to hold 1 atmosphere of pressure to prevent fumes or liquid to escape with normal daily temperature changes [expansion and contraction], hence the name "diurnal system".

I wonder how the recreational boat pollution per day compares with the pollution created by a weekend golf outing to Maralago on Air Force One ...........

Just a thought ........

[ssobol]