Mine Safety & Health Administration http://www.msha.gov
SAE International Aerospace Technology http://aerospace.sae.org
United States Environmental Protection Agency, EPA http://www.epa.gov

OVERVIEW: This rule addresses air pollution concerns by adopting national standards for several types of non-road engines and vehicles that are currently unregulated. These include large spark-ignition engines used in industrial and commercial applications such as those used in forklifts, airport ground service equipment and farm equipment. These emission standards and requirements went into effect for the 2007 model year.

REGULATED ENTITIES: This action will affect companies that manufacture or introduce into commerce any of the engines or vehicles subject to the emission standards. There are also requirements that apply to those who rebuild any of the affected non-road engines. Included among the regulated categories and entities are:

Note: This list is not intended to be exhaustive but rather provides a guide regarding entities likely to be regulated by this action. To determine whether this action regulates particular activities you should carefully examine the regulations.

EVAPORATIVE EMISSIONS: Among the sources of emissions included in the regulations, effective as of the 2007 model year, are “evaporative emissions”. Evaporative emissions occur when fuel evaporates and is vented into the atmosphere. They can occur while a vehicle is operating and even while it is not being operated. Among factors that may affect evaporative emissions are: 1) the proximity of the fuel tank to the exhaust system or other heat sources; 2) whether the fuel system is sealed; and 3) the pressure at which the fuel vapors are ventilated. Such evaporative emissions can represent a significant part of the overall hydrocarbon emissions from such regulated engines. Engine manufacturers are responsible for ensuring that their gasoline-fueled large spark ignition engines are designed to function within the strict emission limitations specified by the Environmental Protection Agency.

Among the design alternatives available to engine manufacturers in their efforts to minimize emissions is the use of a pressurized fuel tank system. Pressurized fuel tanks help control evaporative emissions by suppressing vapor generation. One key element of such a pressurized fuel system is the fuel cap. The cap must be able to seal against a defined fuel tank pressure and must also be able to provide some level of vacuum relief (make-up air) as the fuel tank is emptied. In addition, the cap should be self-closing so that the fuel tank is not inadvertently left open to the atmosphere.

Protectoseal’s line of Fuel Tank Safety Caps are specifically designed to help engine manufacturers meet the stringent EPA fugitive emission requirements. The caps are available in a number of sizes and styles to meet the fill pipe configurations of large spark ignition engines. When properly mounted and closed, the spring-loaded Protectoseal Safety Cap provides an effective seal against emissions (leakage) past the cap gaskets when the fuel tank pressures are as high as 3.5 PSIG. The caps are designed to start relieving at fuel tank pressures between 3.5 PSIG and 4.5 PSIG. At pressures above the set venting point, the caps allow vapors to relieve into the atmosphere – helping to protect engine components against over-pressurization. The cap is also equipped with a check valve that seals against positive pressure but allows the entry of air into the fuel tank should a vacuum develop in the tank’s vapor space.

Even if the setting spring closure mechanism is not properly engaged, the Protectoseal Fuel Tank Safety Cap closes automatically by the action of a torsion spring. This eliminates the possibility of the fuel tank being left completely open to the atmosphere. In order to realize the full set point for the safety cap, the setting spring mechanism must be engaged.

Protectoseal Fuel Tank Safety Caps are Listed by Underwriters’ Laboratories to the requirements specified in Standard UL 558 (“Industrial Trucks, Internal Combustion Engine Powered”).