Connecting vertical drain pipes to horizontal drain pipes

Plumbing · Traps · printed page 288 (PDF page 289)

Book index entries

Connecting Vertical Drain Pipes to Horizontal Drain Pipes Drains – Plumbing – Connecting Vertical Pipes to Horizontal Pipes Plumbing

Text in the illustration

vertical drain from fixture above
horizontal waste pipe
slope: 1/4" per ft.
tee wye fitting is not acceptable
a wye fitting is correct for this connection
note: a tee wye fitting can be used to connect a vent pipe to horizontal waste pipe

Generated explanation

Two circular diagrams compare connections from a vertical fixture drain to a horizontal waste pipe. The left diagram, marked with a red X, shows an unacceptable tee wye fitting, with flow arrows splitting in opposite directions at the junction. The right diagram, marked with a green check, shows a bend and wye fitting directing the vertical discharge downstream into the horizontal pipe. Both horizontal waste pipes are labeled with a slope of 1/4 inch per foot. A note distinguishes drainage from venting by stating that a tee wye fitting can connect a vent pipe to a horizontal waste pipe.

Components

vertical fixture drain horizontal waste pipe tee wye fitting wye fitting drain pipe bend

Defects shown

Unacceptable tee wye fitting connecting a vertical drain to a horizontal waste pipe