When running a water supply tube to a new refrigerator ice maker, humidifier, or other appliance, you'll need a way to tap into an existing water supply pipe. An easy way to do this on copper or steel pipes is by using a special shutoff fitting known as a saddle valve or needle valve. The term saddle derives from the shape of the valve as it sits atop a water pipe; the term needle valve refers to the sharp, hollow needle inside the valve that punctures the water pipe after the valve is mounted. The design of the saddle/needle valve is quite different than a standard water shutoff valve.
Once the valve is attached to the water supply pipe by means of its saddle bracket, the sharp valve needle is then screwed down to puncture the wall of the pipe and tap its water supply. These valves are designed to work with brass, copper, or steel pipes—they do not work with PVC, CPVC, or PEX plastic pipe. And saddle valves are designed for water systems with a maximum pressure of no more than 125 PSI.
Tools and Supplies You Will Need
- Fine wet/dry sandpaper or steel wool
- Saddle valve kit
- Water supply tubing
- Adjustable wrench
Turn off the Water
Shut off the water supply to the water pipe being tapped. If there is no shutoff valve that can turn off the pipe locally, turn off the water to the entire house at the main shutoff valve.
Prepare the Pipe
Make sure the water pipe is clean and smooth along the section where you will be attaching the valve. If necessary, lightly sand the area with fine wet/dry sandpaper or fine steel wool to clean the pipe.
Mount the Valve
Place the rubber washer or gasket on the underside of the top bracket of the saddle valve so its opening is directly aligned with the needle on the valve. Fit the top and bottom brackets of the saddle valve around the water supply pipe and hold them in place.
Insert the bolts down through the holes on the top bracket and thread them into the holes on the bottom bracket until they are hand-tight. Note: Some saddle valves have nuts that tighten against the bottom of the bottom bracket.
Use a screwdriver to tighten the bolts completely, alternating side-to-side so the brackets are tightened evenly on both sides of the pipe. The rubber washer under the top bracket should compress slightly against the water pipe. Be careful not to overtighten; it is possible to crush the copper pipe.
Install the Water Supply Tube
Fit the compression nut and compression sleeve onto the water supply tube so the tapered (narrower) part of the sleeve faces the end of the tube (plastic or nylon tubing may also have a brass insert to stiffen the end of the tubing). Insert the water supply tube into the threaded outlet on the saddle valve, push the sleeve against the outlet, then screw the compression nut onto the threaded outlet. Tighten the nut by hand until snug, then use an adjustable wrench to tighten the nut another one-half turn.
Pierce the Pipe
Turn the saddle valve handle clockwise slowly. This will force the needle in the valve to pierce the wall of the pipe. You should be able to feel the needle force its way into the copper pipe. Keep turning the handle until it stops.
Turn on the Water
With the saddle valve still in the off position (turned fully clockwise), turn on the water supply to the pipe, then check all around the saddle valve for leaks.
Connect the Supply Tube
Complete the water connection by attaching the opposite end of the water supply tube to the appliance you are feeding. Once all connections are made, open the saddle valve fully by turning the handle counterclockwise until it stops. Check again for leaks at all connections.
Variations for Galvanized Steel Pipe
Galvanized steel pipe is too hard to be pierced by the hollow needle in the saddle valve, so you must drain the pipe after shutting off the water, then, drill a 5/32-inch hole in the pipe to fit the needle. When installing the valve, carefully position the saddle valve so the needle aligns with the hole in the pipe. All other steps are the same as for copper pipe.