As of 2026, several ASSE backflow prevention assembly standards are at different stages of publication, revision, and harmonization. The most significant activity centers on harmonized standards for reduced pressure principle (RP) and double check (DC) backflow prevention assemblies, while the detector assembly standards remain outside the current harmonization effort.
HARMONIZATION ACTIVITIES FOR RP AND DC ASSEMBLIES
Harmonization work continues to focus on RP and DC backflow prevention assemblies. These activities are intended to align applicable ASSE and CSA requirements where active equivalent standards exist.
ASSE 1013/CSA B64.4
ASSE 1013/CSA B64.4, Reduced Pressure Principle (RP) Backflow Prevention Assemblies, was published in April 2026. The harmonized revision remains largely consistent with the previous ASSE 1013-2021 standard, with primarily formatting-related updates. One notable technical change is that the test pressure for life-cycle testing and check valve drip-tightness testing was lowered from 175 psi to 150 psi. (Note: Before the 2021 edition, this value was 150 psi. This change returns it to its original value.)
ASSE 1015/CSA B64.5
ASSE 1015/CSA B64.5, Double Check Backflow Prevention (DC) Assemblies, is in the final stages of development. The draft revision is expected to proceed to Canadian and ANSI public review, with publication anticipated in the second quarter of 2027.
ASSE 1047 AND ASSE 1048
ASSE 1047, Reduced Pressure Detector Backflow Prevention Assemblies, and ASSE 1048, Double Check Detector Backflow Prevention Assemblies, are not undergoing harmonization at this time. There are no active equivalent standards in the CSA B64 series for these detector assembly standards.
In summary, ASSE 1013/CSA B64.4 has been published as a harmonized standard; ASSE 1015/CSA B64.5 is nearing public review, with publication expected in 2027; and ASSE 1047 and ASSE 1048 remain outside the current harmonization process due to the absence of active CSA B64 equivalents.
