This Standard specifies requirements for the installation of SDR 9 CTS crosslinked polyethylene (PEX) tubing and fittings, including cold‐expansion, crimp, press, push‐fit, and mechanical compression fittings, intended for hot‐ and cold‐water distribution systems within buildings.

This Standards applies to, 
(a) SDR 9 CTS PEX tubing complying with ASTM F876 or CSA B137.5 and pressure‐rated in accordance with PPI TR‐3; and
(b) PEX fitting systems complying with
(i) ASTM F877, for mechanical compression fittings
(ii) ASTM F1807, ASTM F2159, or ASTM F2735, for metal or plastic insert fittings with copper crimp rings or stainless steel clamps (ASTM F2098);
(iii) ASTM F1960, for cold expansion fittings with PEX reinforced rings;
(iv) ASTM F2080, for cold expansion fittings with metal compression sleeves.
(v) ASTM F3347 or ASTM F3348 for metal or plastic insert fittings with stainless steel press sleeves; or
(vi) ASSE 1061 for Push‐fit fittings.