1.1 ,This specification covers cold expansion fittings and cross-linked (PEX) reinforcing rings for use with cross-linked polyethylene (PEX) plastic tubing in nominal tubing sizes of ³/₈ ,, ¹/₂ ,, ⁵/₈ ,, ³/₄ ,, 1, 1¹/₄ ,, 1¹/₂ ,, 2, 2¹/₂ ,, and 3 in. that meet the requirements of Specification F876 or F3253 and for use with Polyethylene of Raised Temperature (PE-RT) pipe in nominal tubing sizes of ³/₈ ,, ¹/₂ ,, ⁵/₈ ,, ³/₄ ,, 1, 1¹/₄ ,, 1¹/₂ ,, 2, 2¹/₂ ,, and 3 that meet the requirements of Specification F2769. These fittings are intended for use in 100 psi (690 kPa) cold- and hot-water distribution systems operating at temperatures up to and including 180 ,°,F (82 ,°,C). The system is comprised of a PEX reinforcing ring and a cold expansion fitting. Included are the requirements for materials, workmanship, dimensions, and markings to be used on the fitting components. The components covered by this specification are intended for use in residential and commercial, hot and cold, potable water distribution systems as well as sealed central heating, including under-floor-heating systems.