This paper presents test data on evaporative emissions from fuel tanks used in nonroad equipment. Measurements were made on diurnal, running loss, diffusion, and fuel tank permeation emissions. In this effort, baseline test data were collected on fuel systems that are representative of current nonroad equipment. The impacts of several test parameters on evaporative emissions were also investigated. These test parameters included temperature, fuel type, and test configuration. As temperature increased, evaporative emissions increased in all cases. In addition, blending 10 percent ethanol into the test fuel increased permeation emissions for most materials.
Data are also presented on several emission control technologies. For venting emissions, the evaluation included limited flow vent paths, passively purged carbon canisters, and insulation effects. For permeation, the evaluation included surface treatments, barrier layers, and alternative materials. This test data suggests that significant reductions in evaporative emissions can be achieved using these technologies.