OATEY PP9817 Dearborn® 1-1/2" x 8" Branch Tailpiece, Slip Joint Top w/ 3/4" Branch

A branch tailpiece drops from the sink strainer into the P-trap and gives you an extra threaded inlet on the side so a second drain line can tie in without cutting into the trap arm. The Oatey Dearborn PP9817 is a 1-1/2 inch by 8 inch tailpiece with a 3/4 inch threaded branch, so it's the piece you use when a dishwasher drain, water filter, or condensate line needs a legal connection above the trap.

The top is a slip joint connection, and the slip joint nut and washer are part of the assembly, so you don't need to source them separately. Slide the nut and washer onto the strainer or sink outlet and tighten. Nothing is threaded at the top, so it will not screw directly onto a threaded strainer outlet.

The branch is 2 inches to center, measured on an 8 inch overall tailpiece. That leaves plenty of length below the branch to land in the trap, and it puts the side outlet high in the cabinet, which is what you want for a dishwasher high loop or an air gap return.

No. This one is sized 1-1/2 inch, which is the standard kitchen sink and commercial sink drain size. A 1-1/4 inch bathroom lavatory needs a 1-1/4 inch tailpiece, or a reducing washer if you're adapting into a 1-1/2 inch trap. Don't try to force the 1-1/2 inch slip nut onto a 1-1/4 inch strainer.

It's polypropylene, white. Polypropylene handles hot wastewater and drain cleaners well and won't corrode the way thin-wall chrome brass does, which is why it's the common choice for property maintenance and repeat-repair work. The tradeoff is looks: on an exposed ADA or pedestal sink where the trap is visible, a chrome tubular tailpiece is the better call.

The branch is threaded at 3/4 inch, so it takes a threaded hose adapter or dishwasher wye fitting rather than a push-on or slip connection. If the branch isn't being used on the install, it needs a 3/4 inch threaded plug or cap, since the branch is not blanked off from the factory.

Yes, the Dearborn branch tailpiece line is offered with either a 1/2 inch or a 3/4 inch branch, and in white or black polypropylene. The PP9817 specifically is the white, 3/4 inch branch version. Match the branch size to the tubing or adapter you are tying in, since the branch is threaded and won't accept a mismatched fitting.

It's built for soft plastic pipe, and the slip joint washer seals on that. A True Blue premium washer is offered on the Dearborn branch tailpieces for tighter sealing. On thin-wall chrome brass tubular you generally want a washer rated for metal tube instead, since the sealing behavior differs.

Roughly 0.186 pounds each, with a volume of 0.046, so it's light enough to carry several on a truck without thinking about it. That matters for MRO and property maintenance stock, where branch tailpieces get replaced along with washers on routine under-sink calls.