(a) Air Tanks 1971 and Later. Auxiliary air tanks on vehicles first manufactured and registered after January 1, 1971, shall be constructed and marked in accordance with the 1962 or any later edition of section VIII, Unfired Pressure Vessels, ASME Boiler and Pressure Vessel Code (American Society of Mechanical Engineers), or with SAE Standard J10 in the 1965 or any later edition of the SAE Handbook.

(b) Air Tanks Before 1971. Auxiliary air tanks on vehicles registered prior to January 1, 1971, shall meet the requirements of preceding subsection (a), or they shall be designed and constructed in accordance with recognized engineering practices and standards with a safety factor of not less than four times the tank working pressure.

(c) Securement. Auxiliary air tanks shall be positioned and secured so that, when the vehicle is fully loaded, the bottom of the tank and any connection thereto is not lower than the lowest horizontal edge of the vehicle axle.

(d) Tubing and Hose Requirements. All tubing and hose used in the installation of air tanks subject to this section shall comply with the specific requirements for brake tubing and hose in Section 1245(h) through (k) of this title. This provision shall not apply to auxiliary air-actuated systems equipped with air pressure protection devices that prevent the air pressure in the service brake system from dropping below 60 pounds per square inch in the event of air pressure loss from any portion of the auxiliary system, provided the tubing, hose, and fittings used in such installations are designed for air pressure applications.