Building Permit Glossary
TPR Discharge Pipe
The temperature-and-pressure-relief discharge piping that safely directs water away if a water heater relief valve opens.
PlumbingSafety
Applies to
Water heaters · Plumbing
Project example
A replacement water heater needs a correctly sized, routed, and terminated TPR discharge pipe rather than a capped valve.
Also called
T&P dischargerelief valve pipe
Where this term shows up in permit work and how it affects the project
A missing or improper discharge path is a safety and inspection issue that can turn a quick replacement into a correction visit.
If this term appears in a form, plan comment, or local ordinance, start with the building permit guide, compare it against the zoning permit guide, then use the permit guide directory to find the right local path.