Slip-Joint Connection
A slip-joint connection seals a drain pipe with a beveled nylon washer compressed by a hand-tightened nut, the take-apart joint used on sink traps and tailpieces.
A slip-joint is the friendly, tool-light connection you find under almost every sink. A plastic or chrome nut slides over the pipe and squeezes a tapered nylon or rubber washer against the mating piece, sealing the joint without glue or solder. Because it only needs hand pressure or a gentle turn with channel-lock pliers, it lets the curved trap, the tailpiece off the drain, and the arm to the wall all be loosened and re-aimed during assembly or cleaning.
Homeowners meet slip-joints whenever they clear a clog by taking the P-trap apart, swap a drain assembly, or chase a leak under the kitchen sink. The whole point is that the connection comes apart, which is also its weakness: a washer that is worn, cross-threaded, or missing, or a nut overtightened until the plastic cracks, will weep. A slow drip under a cabinet is very often nothing more than a tired slip-joint washer that costs pennies to replace.
Slip-joints belong on drain and trap lines, which carry water at low pressure, not on pressurized supply lines where the constant push would blow past the washer. Getting one to seal is mostly about clean threads, a fresh washer seated squarely, and snug-but-not-gorilla tightening.
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- PEX (Cross-Linked Polyethylene) : PEX is flexible plastic water-supply tubing that bends around corners and runs in long lengths with few fittings, now the most common material for whole-house repipes.
- Copper Pipe : Copper pipe is rigid metal water-supply tubing joined by soldered or pressed fittings, prized for durability and a long service life but more labor-intensive and costly to install than plastic.
- CPVC : CPVC is a rigid cream-colored plastic pipe rated for hot water that joins with solvent cement, used for water supply as a lower-cost alternative to copper.
- Galvanized Pipe : Galvanized pipe is old steel water pipe coated in zinc that corrodes and clogs from the inside over decades, a common cause of low pressure and rusty water in pre-1970 homes.