(a) Where a carbon dioxide extinguishing system is installed, the provisions of this subpart, with the exception of Sec. 95.15-90, shall apply to all installations contracted for on or after November 19, 1952. Installations contracted for prior to November 19, 1952, shall meet the requirements of Sec. 95.15-90.
(b) The requirements of this subpart are based on a ``high pressure system,'' i.e., one in which the carbon dioxide is stored in liquid form at atmospheric temperature. Details for ``low pressure systems,'' i. e., those in which the carbon dioxide is stored in liquid form at a continuously controlled low temperature, may be specifically approved by the Commandant where it is demonstrated that a comparable degree of safety and fire extinguishing ability is achieved.