Developing Regulations
On May 18, 2007 EPA proposed a rule to control emissions from nonroad spark-ignition engines and equipment. Included in the preamble and the rule itself are the requirements that boat builders are expected to meet in the designing and building of new boats. Two requirements that are directly related to refueling deal with spilling and spitback during refueling, and preventing liquid fuel from entering the carbon canister.
EnviroFill's O.P.S. technology has been described in the preamble as one method of preventing spilling and spitback. Regulating marine fuel dock nozzle spout geometry has been proposed, and is supported by number of manufacturers that commented on the rule. The comment period ended August 3, 2007. EPA is now writing the final rule and it is expected to be published by June in 2008.
Enviro-Fill has proposed that EPA allow boat builders to install a design certified tank/fill system as one method of meeting refueling requirements of this rule including preventing liquid fuel from entering the carbon canister. This system would consist of the fuel tank with an installed fuel level sensor designed for that individual tank and a deck fill fitting that uses pressure transfer technology (patent pending) to shut off the nozzle at a predetermined level in the tank. This method of preventing overfilling of the tank works independent of the boat and requires no new access panels or changes to the boat itself.
This page will be updated as information becomes available. Please see the refueling related portions of the proposed rule.
Preamble- to proposed rule
(6) Requirements Related to Refueling
Refueling spitback and spillage emissions represent a substantial additional amount of fuel evaporation that contributes to overall emissions from equipment with gasoline-fueled engines. We are not proposing measurement procedures with corresponding emission standards to address these emission sources. However, we believe equipment manufacturers can take significant steps to address these refueling issues by incorporating sound practices into their equipment designs. For example, designing a marine filler neck with a horizontal segment near the fuel inlet will almost inevitably lead to high levels of spillage since fuel flow will invariably reach the nozzle, leading to substantial fuel flow out of the fuel system. In contrast, designing for automatic shutoff would prevent this. Also, maintaining a vertical orientation of the filler neck would allow the fuel to flow back into the filler neck and into the tank after the nozzle shuts off.
For Small SI equipment, designing fuel inlets that are readily accessible and large enough to see the rising fuel level (either through the tank wall or the fuel inlet) will substantially reduce accidental spillage during refueling. We are therefore proposing to require that equipment manufacturers design and build their equipment such that operators could reasonably be expected to fill the fuel tank without spitback or spillage during the refueling event (see §1060.101). This proposed requirement mirrors the following requirement recently adopted with respect to portable fuel containers (72 FR 8428, February, 26, 2007):
You are required to design your portable fuel containers to minimize spillage during refueling to the extent practical. This requires that you use good engineering judgment to avoid designs that will make it difficult to refuel typical vehicle and equipment designs without spillage. (40 CFR 59.611(c)(3))
While the proposed requirement is not as objective and quantifiable as the other standards and requirements we are proposing, we believe this is important, both to set a requirement for manufacturers in designing their products and to give EPA the ability to require manufacturers to select designs that are consistent with good engineering practice regarding effective refueling strategies. To the extent that equipment manufacturers and boat builders certify their products to emission standards, they would need to describe how they meet this refueling-related requirement in their application for certification. If boat builders rely on certified components instead of applying for certification, they would need to keep records describing how they meet this refueling-related requirement; Section VI.F describes how such companies can meet certification requirements without applying for a certificate. We request comment on this approach to addressing refueling emissions from nonroad spark-ignition engines. We also request comment on the possibility of relying on current or future published industry standards to establish designs for equipment and fueling containers that minimize refueling emissions under normal in-use conditions.
Spitback and spillage are a particular concern for gasoline-fueled boats. Marine operators have reported that relatively large quantities of gasoline are released into the marina environment during refueling events. The American Boat and Yacht Council (ABYC) has a procedure in place to define a standard practice to address refueling. However, this procedure calls for testing by refueling up to a 75 percent fill level at a nominal flow rate of 5 gallons per minute. This procedure is clearly not consistent with prevailing practices and is not effective in preventing spills. We believe the most effective means of addressing this problem is for ABYC to revise their test procedure to reflect current practices. Specifically, we would recommend a procedure in which the marine fuel tank is filled at flow rates between 5 and 20 gallons per minute until automatic shutoff occurs.
A variety of technological solutions are available to address spitback and spillage from marine vessels. The simplest would be a system much like is used on cars. A small-diameter tube could run along the filler neck from the top of the tank to a point near the top of the filler neck. Once liquid fuel would reach the opening of the filler neck and the extra tube, the fuel would go faster up the small-diameter tube and trigger automatic shutoff before the fuel climbs up the filler neck. This design would depend on the user to use the equipment properly and may not be fully effective, for example, with long filler necks and low refueling rates. An alternative design would involve a snug fit between the nozzle’s spout and the filler neck, which would allow for a tube to run from a point inside the tank (at any predetermined level) directly to the shutoff venturi on the spout. The pressure change from the liquid fuel in the tank reaching the tube’s opening would trigger automatic shutoff of the nozzle. This system would prevent overflowing fuel without depending on the user. These are just two of several possible configurations that would address fuel spillage from marine vessels.
We request comment on the degree of fuel spillage with current technologies and practices with marine vessels. We request comment on the potential for ABYC standards to address fuel spillage or on the need for EPA to adopt such procedures and standards. We request comment on the specific procedures that would be appropriate for measuring spitback and spillage. Finally, we request comment on adopting provisions such as those in 40 CFR 80.22 to regulate the dimensions of refueling nozzles for marine applications, including a specification of a nominal nozzle diameter of 1.187±0.010 inches and nominal venturi placement 5/8 inch from the terminal end of the nozzle.
Excerpt from proposed rule
(1) Fuel caps, vents, and carbon canisters. You are responsible for
ensuring that proper caps and vents are installed on each new piece of equipment that is subject to emission standards under this part. The following particular requirements apply to equipment that is subject to running loss, diurnal, or diffusion emission standards:
(i) All equipment must have a tethered gas cap. Fuel caps for
equipment subject to diurnal requirements must include a visual or audible indication when it is properly sealed.
(ii) You may not add vents unless they are allowed by the applicable certificates of conformity.
(iii) If the emission controls rely on carbon canisters, they must be installed such that they will not be exposed to water or liquid fuel.
(2) Fuel-line fittings. The following requirements apply for fuel-line fittings that will be used with fuel lines that must meet permeation emission standards:
(i) Use good engineering judgment to ensure that all fuel-line fittings will remain securely connected to prevent fuel leakage throughout the useful life of the equipment.
(ii) Fuel lines that are intended to be detachable (such as those for portable marine fuel tanks) must be self-sealing when detached from the fuel tank or engine.
(3) Refueling. For any equipment using fuel tanks that are subject to diurnal or permeation emission standards under this part, you must design and build your equipment such that operators can reasonably be expected to fill the fuel tank without spitback or spillage during the refueling event. The following examples illustrate designs that meet this requirement:
(i) Equipment that is commonly refueled using a portable gasoline container should have a fuel inlet that is larger than a typical dispensing spout. The fuel inlet should be located so the
operator can place the nozzle directly in the fuel inlet and see the fuel level while pouring the fuel (either through the tank wall or the fuel inlet).
(ii) Marine SI vessels with a filler neck extending to the side of the boat should be designed for automatic fuel shutoff. Alternatively, the filler neck should be designed such that the
orientation of the filler neck allows dispensed fuel that collects in the filler neck to flow back into the fuel tank. A filler neck that ends with a horizontal or nearly horizontal segment at the opening where fuel is dispensed would not be an acceptable design.
