A sink tailpiece is the outlet section below a sink's strainer or drain body that carries wastewater toward the trap. It is often a straight tube, although particular assemblies can include a branch connection or a different outlet arrangement. Its top connection, tube dimensions and lower connection must match the actual drain components.
A sink tailpiece is the outlet section below a sink's strainer or drain body that carries wastewater toward the trap. It is often a straight tube, although particular assemblies can include a branch connection or a different outlet arrangement. Its top connection, tube dimensions and lower connection must match the actual drain components.
Locate it between the sink drain and trap
Start at the drain opening in the bowl and follow the drain downward. The strainer or pop-up drain body is attached to the sink. The tailpiece continues below that body toward the trap connection. The curved trap performs a different job: its retained water helps seal off sewer gas.
Kohler's pop-up drain instructions label the tailpiece separately from the drain body and tell the installer to connect the P-trap to it. That particular guide also specifies a washer inside the drain body when its tailpiece has been removed. It illustrates why the top and bottom connections should be identified separately rather than treated as one generic threaded joint.
A supply hose carries clean water to the faucet. A tailpiece carries drain water away. Identifying which side is wet helps explain what a repair estimate is describing, though the first visible drip does not always identify the original leak.
A branch tailpiece changes the parts description
Oatey's tubular-pipe guide describes branch tailpieces that provide a dishwasher discharge connection in suitable sink arrangements without a disposal. The branch has a separate purpose from the straight outlet leading to the trap. It is not a second sink trap or permission to connect any appliance hose to any available opening.
The required dishwasher drainage arrangement still depends on the appliance instructions and applicable code. Our dishwasher air-gap guide covers that separate backflow-protection question.
Material and connection style also matter. A tailpiece associated with a particular pop-up body may use a different upper seal from a flanged strainer tailpiece or a slip-joint extension. Similar length and appearance do not establish interchangeability. Follow the drain manufacturer's parts specification instead of assuming every end takes the same washer or sealant.
What to identify before replacing the outlet section
Photograph the sink drain body, tailpiece and trap together. Record the material, marked size, available length and any branch connection. Ask which part is being replaced and how its two ends connect to the existing assembly.
If a new sink or drain leaves the trap at the wrong height or alignment, do not force the tube sideways or assume adding an extension fixes the whole layout. Our kitchen sink guide explains the assembly context. The slip-joint washer entry explains one common lower seal, while the actual upper drain connection may work differently.