Kitchen Sink Water Line Connections

Installing or replacing water lines under a kitchen sink requires careful attention to detail to ensure a leak-free connection. Water supply lines come in a variety of materials, each with its pros and cons. Here's a guide to help you understand the different types of water line connections and how to install them properly.

Types of Water Line Connections

1. Compression Fittings:

Compression fittings are the most common type of water line connection. They use a ferrule, nut, and washer to create a seal. Compression fittings are relatively easy to install and are available in various sizes.

2. Push-Fit Fittings:

Push-fit fittings, also known as SharkBite fittings, do not require any tools for installation. They simply push onto the pipe and create a leak-proof connection. Push-fit fittings are easy to use and are a good option for DIYers.

3. PEX Fittings:

PEX (cross-linked polyethylene) fittings are made of a flexible plastic material. They are corrosion-resistant and can withstand high temperatures. PEX fittings require specialized tools for installation.

Installing Water Lines

1. Tools and Materials:

To install water lines, you will need the following tools and materials:

Adjustable wrench
Basin wrench
Teflon tape
Water line fittings (compression, push-fit, or PEX)
Water supply lines
Pipe cutter or hacksaw

2. Shut Off Water Supply:

Before starting any work, shut off the water supply valves under the sink.

3. Disconnect Existing Lines:

If replacing old water lines, disconnect them from the shut-off valves and faucet. Use an adjustable wrench or basin wrench to loosen the nuts and remove the lines.

4. Cut and Prepare Pipes (PEX Only):

If using PEX lines, measure and cut the pipes to the desired length. Clean the ends of the pipes and remove any burrs.

5. Apply Teflon Tape:

Wrap Teflon tape clockwise around the threaded ends of the water line fittings to prevent leaks.

6. Install Fittings:

For compression fittings, hand-tighten the ferrule onto the pipe. Then, tighten the nut using an adjustable wrench while holding the ferrule with a basin wrench. For push-fit fittings, simply push them onto the pipe until they click into place. For PEX fittings, use a PEX crimp tool to create a secure connection.

7. Connect to Faucet and Valves:

Once the fittings are installed, connect the water lines to the faucet and shut-off valves. Use an adjustable wrench to tighten the nuts.

8. Turn on Water Supply:

Turn on the water supply valves and check for leaks. Tighten any loose connections as needed.