Which Two Types of Copper Tubing Would Be Recommended for a Water Supply Inside a House?

Types of Copper Tubing

• Copper tubing is manufactured in different grades called “Types” to signify its different applications. Type L tubing is commonly used for above-ground plumbing systems and is often required by local building codes. Type M tubing is thinner and typically less expensive than Type L tubing, and is commonly used for above-ground residential plumbing systems if Type L is not required by local law. Type K tubing is the thickest of the three types, and is usually reserved for use in underground plumbing systems. When installing copper water supply lines inside a home, consider using either Type L or Type M tubing, unless your local code requires Type L.

Rigid and Flexible Copper Tubing

• Type L and Type M copper tubing is manufactured in two designs: rigid tubing and flexible tubing. Rigid tubing is a stiff length of pipe typically sold in lengths of 10 or 20 feet. Rigid tubing is an appropriate choice when installing a plumbing system or when replacing long pieces of tubing. It is less expensive than flexible tubing, but you do have to cut the tubing to the appropriate length and prepare the tubing for installation. As its name suggests, flexible tubing bends easily and is easily identifiable by the ridges that run down the length of the tubing. Flexible tubing is commonly used to replace small sections of pipe or to easily route the tubing around obstructions. Flexible tubing is fitted with integral nuts at each end that attach to existing pipe threads, so there is no need to prepare the tubing for installation.

Cutting and Soldering Copper Tubing

• Connecting copper tubing is not as difficult as it may first appear, but you must pay close attention to detail. The first step is to cut the tubing to the desired length. Although a hacksaw can do the job, a pipe cutter will produce a cleaner cut. The cutter resembles the letter “C.” It grasps onto the pipe and a blade cuts through the tubing when you rotate the cutter. Copper is attached together with solder that liquefies when heated. The solder seals the seam between two connecting pieces. Scuff the tip of the pipe with sandpaper until the pipe is a chrome color. To draw the solder into the seam, brush a coat of flux onto the scuffed portion of pipe. Slide the pipe fitting onto the pipe. You must heat the solder indirectly by heating the pipe. Heat the pipe with a propane torch and touch the solder to the pipe. As the solder liquefies, it will fill the seam between the pipe and the fitting. Wear gloves when heating the pipe, as it will warm quickly.

Flaring Copper Tubing

• Some copper tubing applications require integral nuts rather than soldered fittings. You must flare the end of the pipe to prevent it from sliding out of the nut. Flaring means to expand the tip of the pipe. Flaring tools are manufactured for just this purpose. Slide the nut onto the pipe, then insert the pipe into the flaring tool. The tool features a threaded rod that tightens into the center of the tube. The tip of the rod fits within the end of the tube and presses the lip of the tube outward and against the tool to create the flare. If installing tubing inside of a wall, check your local building codes first, as some municipalities prohibit the use of flared tubing inside walls.