Section 65.100 - Applicability(a)Equipment subject to this subpart. The provisions of this subpart and subpart A of this part apply to equipment that contains or contacts regulated material. Compliance with this subpart instead of the referencing subpart does not alter the applicability of the referencing subpart. This subpart applies only to the equipment to which the referencing subpart applies. This part does not extend applicability to equipment that is not regulated by the referencing subpart.(b)Equipment in vacuum service. Equipment in vacuum service is excluded from the requirements of this subpart.(c)Equipment in service less than 300 hours per calendar year. Equipment intended to be in regulated material service less than 300 hours per calendar year is excluded from the requirements of §§ 65.106 through 65.115 and § 65.117 if it is identified as required in § 65.103(b)(6) .(d)Lines and equipment not containing process fluids. Lines and equipment not containing process fluids are not subject to the provisions of this subpart. Utilities and other nonprocess lines, such as heating and cooling systems that do not combine their materials with those in the processes they serve, are not considered to be part of a process unit.