Plumbing Reference Charts

ABOUT THESE CHARTS

These charts cover the look-ups plumbers, gas fitters, and MEP engineers make while sizing a system: drainage and water supply fixture units per fixture, drain, stack, and building-drain sizes from total DFU by slope, vent sizing with trap-to-vent distances, water pipe and meter sizing from WSFU and developed length, minimum trap and slope requirements, fixture flow and consumption limits, and Schedule 40 natural gas pipe capacity in BTU/hr by developed length.

Model plumbing codes disagree more than electrical ones do, so every chart keeps IPC and UPC values separate and labeled — never averaged or merged — and cites the governing section of each. Gas sizing follows the longest-length method from NFPA 54 / IFGC 402. As always, the adopted code and local amendments in your jurisdiction govern; confirm against the edition your inspector enforces.

When you need a computed answer instead — total fixture units for a specific fixture count, pipe size for a specific demand — each chart links to the matching NORDIX calculator.