5304.1 Upright storage.
FC § 5304.1
Compressed gas containers, except those designed for use in a horizontal position, and all compressed gas containers containing nonliquefied gases, shall be stored in an upright position with the valve end up. The axis of the container stored in the upright position may be inclined as much as 45 degrees (0.80 rad) from the vertical provided that it is properly secured. Exception: Compressed gas containers with an internal volume less than 0.174 ft 3 (0.005 m3) may be stored in a horizontal position.
