There are three parts to this Standard: a) Part 1 contains requirements for boilers, pressure vessels, pressure piping, and fittings. It is intended mainly to fulfill two objectives: first, to promote safe design, construction, installation, operation, inspection, testing, and repair practices; and second, to facilitate adoption of uniform requirements by Canadian jurisdictions. b) Part 2 contains requirements for high-pressure cylinders for the on-board storage of natural gas, blends of natural gas and hydrogen (hydrogen blends), and hydrogen as fuels for automotive vehicles. It has been harmonized with International Organization for Standardization (ISO) Standard 11439:2013, Gas cylinders — High pressure cylinders for the on-board storage of natural gas as a fuel for automotive vehicles. In addition, the CSA Subcommittee responsible for developing Part 2 has consulted with the American National Standards Institute (ANSI) committees responsible for developing CSA/ANSI NGV 2-2016, Compressed natural gas vehicle fuel containers, and CSA/ANSI HGV 2-2014, Compressed hydrogen gas vehicle fuel containers. The members of these two committees are dedicated to harmonizing their standards as far as circumstances allow. c) Part 3 contains requirements for compressed natural gas and hydrogen refuelling station pressure piping systems and ground storage vessels. These requirements have been allotted a separate part of the Standard to emphasize the differences between them and the requirements in Part 1, thereby facilitating their application.