Hooking up the supply lines.
Photo: Kolin Smith

Step 7: Hook up the supply lines

For braided supply lines: Screw the ½-inch compression fitting to the faucet valve. Screw the -inch fitting to the water shutoff valve.

For rigid supply lines: Slide a ½-inch nut from a compression fitting onto the supply line (you don't need the brass ring, or ferrule, here). Hand-tighten it to the faucet valve over the acorn head. Slide the -inch nut and then a ferrule from the fitting onto the line. Hand-tighten the nut to the water shutoff valve over the ferrule.

Using an adjustable wrench tighten the ½-inch nut an extra quarter-turn. Then, using tongue-and-groove pliers, hold this connection steady while you tighten the -inch nut on the water shutoff valve a quarter-turn. Repeat for the other supply line.

TIP: Get more access to the connection at the water shutoff valve by removing the valve's knob. Just be sure to hold the knob to keep the water supply turned off as you loosen its set screw.
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    Tools List

    • adjustable wrench
      Adjustable wrench
    • basin wrench
      Basin wrench,
      to reach parts under the sink
    • allen wrench set
      Allen wrenches,
      tp tighten set screws
    • tube bender
      Tube bender,
      for putting curves in rigid supply lines
    • pvc pipe cutter
      Pipe cutter
    • tongue-and-groove pliers
      Tongue-and-groove pliers,
      to turn large nuts and to hold parts steady when tightening fittings

    Shopping List

    1. FAUCET

    Most come with spout, valves, braided line to connect the valves, handles, drain collar, and pop-up waste assembly, though some valves and handles are sold separately. Look for parts made from solid brass (under the finish) or stainless steel for the best quality.

    2. 3/8-inch supply lines

    to connect the sink's valves to the water supply, either rigid or braided. Rigid supply lines (aka risers) should be used in an exposed installation, but they might need to be bent to fit, which takes some finesse. Buy three (just in case) in a chrome finish for the best appearance and in lengths longer than you need. Make sure you get the ones with an "acorn head" which becomes part of the connection to the faucet valves. You will also need to buy compression fittings. [BR] Braided-steel lines are flexible and therefor easy to install but aren't as pretty. They come in various lengths, with fittings on the ends. Make sure to buy them only slightly longer than you need, with a 3/8-inch compression fitting on one end and a 1/2-inch fitting on the other.

    3. 3/8x1/2-inch compression unions

    (if needed) to connect rigid supply lines.Get two; each should include two complete compression fittings, one 3/8-inch and one 1/2-inch, which you can cannibalize for your connections. Otherwise, get two 3/8-inch fittings and two 1/2-inch fittings separately.

    4. Clear silicone sealant

    Instead of plumber's putty, to seal gaps around the valves, spout, and drain collar. Some manufacturers warn that using plumber's putty will void their finish warranties because the oil-based product can cause damage.

    5. Teflon tape

    6. Rubbing alcohol