OATEY 42156 Rubber Caulking Gasket Fits 2 in. Sch. 40 DWV Drain Pipe in the No-Calk Shower Drains

The 42156 is the rubber compression gasket that seals a No-Calk shower drain body to 2 inch Sch. 40 DWV pipe. You drop the drain over the riser, seat the gasket, then tighten the caulking nut down with a wrench so the rubber compresses around the pipe. No lead, no oakum, no hot work. It's the sealing element, not the drain body and not the strainer.

Yes, and that's exactly what the 42156 is for. On a No-Calk drain the seal is made entirely by the rubber gasket compressed by the caulking nut, so a weep around the riser is usually a tired or displaced gasket rather than a failed drain body. Back the nut off, pull the old rubber, seat the 42156, and retighten. The cast body and strainer stay in the floor.

For slab construction the No-Calk approach is what Oatey points this part at, and the reason is practical: the joint is made mechanically with a rubber gasket and a caulking nut instead of poured lead, so there's no torch or molten metal at the deck and the drain can be set and tightened after the riser is already fixed in the pour. The trade-off is that the connection depends on the gasket being the right one for the pipe, which is why the 42156 is specified to 2 inch Sch. 40 DWV.

The 42156 is the rubber gasket only. The No-Calk shower drain assemblies it goes into carry the body and a Snap-Tite strainer, in stainless steel or UltraShine PVD polished brass, and the caulking nut that compresses the gasket. If you are building a drain from scratch rather than replacing a worn seal, you need the drain assembly, not just this gasket.