What Are the Plumbing Parts of a Sink?

What are all those pipes under your kitchen sink? When we install an undermount kitchen sink, we have to disassemble and reinstall the sink’s plumbing.

That’s why it’s so important to have a professional plumber complete this job.

• Appliances & Accessories: Various appliances and accessory devices often have to be removed and then reinstalled, adding cost and complexity to a kitchen sink reinstallation. These include the obvious appliance devices like the garbage disposal, but also items such as reverse osmosis spouts, instant hot water dispensers, soap dispensers, dishwasher air gaps, etc. Occasionally the kitchen faucet may also need to be removed and reinstalled. Since undermount sink work involves complete removal and installation of all components, this process is a perfect time to consider upgrading to a better, more powerful, and quieter garbage disposal. Earl’s Plumbing has multiple garbage disposal options for you to consider, or you can provide your own and we will install it for you.
• Water Supply Lines: You have two water supply lines (tubes)—one for hot water and one for cold. These are usually silver wire mesh but can be made of different materials. They deliver water to your faucet.
• Shut-off Valves: All sources of water for faucets (and toilets) should have a functioning shutoff valve at the wall. Because they have a limited lifespan of about 10 years for builder-grade versions, you should be prepared to replace these valves when making major sink repairs or replacements.
• Drain Assembly: The part that allows you to plug the sink (usually featuring a drain strainer) and the P-Trap (the pipe that looks like a “U”). This may be the most important part of your kitchen sink drain plumbing, as it creates a water seal, preventing smelly, noxious sewer gas from entering the home and acting as a line cleaner. Finally, the assembly ends with a tubular drain pipe called a trap arm. This piece extends from the P-Trap and securely connects to the pipe going into the wall, where it connects to the rest of the drainage system.
• Watertight Components: Threaded slip nuts and slip nut washers make everything watertight, and if they’re not properly installed, end up causing the majority of leaks under sinks. Far too often, people install silicone, caulk, pipe dope, plumbers putty, leak tape, or all sorts of other quick fixes around these areas. Not only are these materials unnecessary when sinks are installed correctly, but using them is also not good plumbing practice.