What is the suggested minimum vertical distance between the relief valve discharge port of a RPZ and the surrounding floor or grade?

The suggested minimum vertical distance between the relief valve discharge port of a Reduced Pressure Zone (RPZ) assembly and the surrounding floor or grade is indeed 12 inches. This specification is essential for ensuring that any discharged water from the relief valve does not create a pool or splashing effect at the discharge point, which could lead to backflow into the potable water supply or create health hazards.

Maintaining this clearance is also important for accessibility and maintenance purposes, as it ensures that the area is clear for inspection and servicing of the RPZ. The height helps facilitate proper drainage away from the device and prevents any blockage, thereby ensuring the RPZ functions effectively in protecting the water supply system from contamination risks.