Rationale

Since it is possible to have a PEX product with a 1400 or a 1600 psi HDB at 73°F, there should be requirements that provide ongoing assurance that materials used to produce tubing according to this specification perform consistently in relation to their pressure ratings. To accomplish this: • Table 1 has new HDS and PR values added with one sentence added to 5.2.1, • One sentence is added to 6.1.5 and Table 5 is completely revised, with different test pressures for different HDBs, and • A new Note 2 is added which refers to ISO reference lines for PEX (ISO 15875) Additionally, since the Quality Assurance Appendix is intended to be a non-mandatory part of this specification, it is reasonable for the Quality Assurance Appendix to use non-mandatory language instead of mandatory language. In general, “shall” is replaced with “should” eleven times.