How high must a PVB be installed above grade?

A pressure vacuum breaker (PVB) must be installed at least 12 inches above grade. This requirement is crucial for proper functioning and to ensure that the system effectively prevents back siphonage. Installing the PVB at this height allows for the necessary air gap that protects the potable water supply from possible contamination.

This distance is specified in plumbing and irrigation codes to ensure that any water that could potentially flow back into the system from downstream does not create a hazard. By adhering to this installation height, you can help maintain the integrity of the irrigation system and safeguard public health.