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American Society of Sanitary Engineering

ASSE backflow prevention

Backflow prevention assemblies protect the potable supply from cross-connection. ASSE guidance, together with the local water authority's rules, governs how an assembly is installed and how it is tested on interval by a certified tester.

Adoption varies by jurisdiction — confirm the edition your authority having jurisdiction enforces before you run a walk against it.

What it covers

  • Assembly type for the hazard level
  • Orientation, clearance and drainage of the installation
  • Annual test procedure and reporting
  • Repair and retest documentation

What the evidence looks like

  • Test kit readings photographed with the assembly tag visible in the same frame.
  • Serial number and model captured so the report cannot be attached to the wrong device.
  • Relief valve discharge and clearance shown as installed.

Common questions

What is ASSE backflow prevention?
Backflow assemblies — installation orientation, clearances and annual testing. It is published by the American Society of Sanitary Engineering. Backflow prevention assemblies protect the potable supply from cross-connection. ASSE guidance, together with the local water authority's rules, governs how an assembly is installed and how it is tested on interval by a certified tester.
What does ASSE backflow prevention cover?
Assembly type for the hazard level; Orientation, clearance and drainage of the installation; Annual test procedure and reporting; Repair and retest documentation.
What does a field inspection against ASSE backflow prevention look at?
Test kit readings photographed with the assembly tag visible in the same frame. Serial number and model captured so the report cannot be attached to the wrong device. Relief valve discharge and clearance shown as installed.
Which edition of ASSE backflow prevention applies to my project?
Adoption varies by jurisdiction — confirm the edition your authority having jurisdiction enforces before you run a walk against it.
Which checklists verify work against ASSE backflow prevention?
2 free checklists in the RTI library reference this family — each listed on this page with the photo evidence every item needs before it can be submitted.

A standard is only met if the evidence exists

RTI holds the submit button until every mandatory item is answered and the photos are attached, then chains the record so it can be proven untouched later.

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