The staff of the California Air Resources Board (CARB) is proposing amendments to the Fill Pipes Specifications to help ensure new motor vehicle fill pipes continue to be compatible and to form a good seal with Phase II recovery nozzles that are certified for use at California gasoline stations, thereby reducing overpressure.
Problematic interfacing between gasoline dispensing facility (GDF) nozzles and some newer vehicle fill pipes cause excess air ingestion at the nozzle. Excess air ingestion in turn causes an increase in storage tank headspace pressure (overpressure) by enhancing gasoline evaporation, which results in the release of gasoline vapor to the atmosphere through gas station vent lines and fugitive leak sources.
These releases increase emissions of toxic air pollutants such as benzene as well as reactive organic gases that can react with other air pollutants to form ozone.
The existing regulations specify vehicle fill pipe dimensions and test procedures. CARB staff proposes to amend the regulation and add a performance leak standard and test procedure to verify a proper seal between the fill pipe and the nozzle, thus reducing air ingestion.
The performance leak standard will quantify an allowable leak rate between the fill pipe face and the nozzle boot. This is necessary, CARB staff said, as new capless fill pipe designs continue to be introduced by multiple manufacturers in California.
A zero leak rate would be hard to achieve with some of the designs on the market today.
The proposed changes phase in a leak standard starting in MY 2022 and being fully phased in for MY 2024 and following.
There are no federal regulations or programs directly comparable to California Specification for FIUll Pipes and Openings of Motor Vehicle Fuel tanks. California’s existing Fill Pipe specs already exceed federal requirements.
In addition, the proposal includes additional dimensional specifications for new fill pipe head designs in a cost effective manner. The proposed amendments are a result of extensive deliberations by vehicle, fill pipe, and nozzle manufacturers.
Staff estimates compliance with the proposed amendments will improve air quality by reducing gasoline vapor emissions by 0.6 tons per day in the year 2030 during winter months on a day with average vapor concentration. Further, the proposed amendments provide certainty and flexibility to both fill pipe and nozzle manufacturers. This rulemaking is coordinated with a parallel rulemaking for gas station nozzle specifications to ensure compatibility between nozzles and fill pipes.
The CARB will conduct a public hearing on 25 October in Sacramento to consider the amendments.