SAE J2601/4
Ambient Temperature Fixed Orifice Fueling

Under development
United States & Other Locales



Society of Automotive Engineers

Fuel Cell Standards Committee - Interface Working Group



SAE J2601/4
Ambient Temperature Fixed Orifice Fueling




SAE J2601/4 establishes the protocol and process limits for hydrogen fueling of light duty vehicles when the fuel delivery temperature is not pre-cooled, so called “ambient fueling” designated by Table 1 of SAE J2601-2014. These process limits (including the fuel delivery temperature, the maximum fuel flow rate, the rate of pressure increase and the ending pressure) are affected by factors such as ambient temperature, fuel delivery temperature and initial pressure in the vehicle’s compressed hydrogen storage system.


SAE J2601/4 establishes standard fueling protocols based on a series of design cases representing fueling system engineering categories. These categories are intended to provide performance targets which allow decreasing fueling times relative to the most simple design case. Similar to the table and formula based approaches of SAE J2601-2014, this approach establishes a minimum performance criteria leaving open options for innovation to decrease fueling times.




June 2020 balloting resulted in numerous comments.

Anticipate the next balloting in first quarter of 2021.





SAE: Staff Support

Caroline Michaels
Pat Ebejer