What should the termination point of a relief valve discharge line be above the floor or flood rim level?

The termination point of a relief valve discharge line must be positioned at least 6 inches above the floor or flood rim level to ensure proper drainage and prevent potential backflow issues. This height ensures that any discharge from the relief valve is directed away from areas where it could cause flooding or damage, as well as preventing any contaminants from entering the water supply. Additionally, this height helps in effectively dissipating any vapor discharge without risk to personnel or any nearby equipment.

In plumbing codes, it's common to establish specific clearances for discharge lines to maintain safety standards and operational integrity. A distance of 6 inches strikes a balance between ensuring adequate clearance and practicality during installation and maintenance. Standards may vary by jurisdiction, but the 6-inch requirement is widely recognized and incorporated into plumbing practices.