To disconnect a soldered fitting, apply heat till the solder melts. Then gently tap the fitting off the pipe. When the metal is cool, clean the pipe end, reflux, reheat, and solder on a new fitting. Unless the fitting is an expensive one, such as a gate valve, don’t reuse fittings that have already been soldered.

When disconnecting a fitting on an existing supply line, drain the pipe first; otherwise, the solder won’t melt. Draining and reconnecting will be much easier if the pipe section can be isolated with a shutoff valve, but sometimes old valves don’t shut perfectly. In that event, ball up a piece of white bread and stick it in the pipe to block the trickle while you solder. Once the water runs again, the bread will dissolve and flush out.

Finally, here’s a fix for split pipes that doesn’t require soldering at all: Cut out the damaged section of pipe and slide a compression repair coupling over the cut pipe ends. (The coupling’s inner diameter is the same as the Vl-in. rigid copper’s outer diameter.) Use a pair of adjustable wrenches to tighten the compression fittings on both ends of the coupling, and you’re done.

Repairing pipes split by freezing water is no big deal with a compression repair coupling. Each end of the coupling compresses a brass ferrule to create a watertight seal without soldering.

soft metal that is compressed between a set of matched nuts. A flared fitting requires that you flare the tubing ends with a special tool. When using either type of connector, remember to slide nuts onto the tubing before attaching a ferrule or flaring an end. Both types of connection are easy to disconnect, and so are used where repairs may be expected, such as the supply line to a toilet. Don’t reuse ferrules, however; replace them if you need to disconnect fittings.

In most situations, braided stainless-steel sup­ply lines are a better choice than flexible copper tubing: Braided lines are strong, look good, and can be connected and disconnected as often as needed.

GALVANIZED STEEL PIPE

Galvanized pipe corrodes and constricts, re­ducing flow and water pressure, so it is no longer installed as water-supply pipe. If your existing system is galvanized and the water flow is weak, replace it as soon as possible. If you’re not quite ready to rip out and replace all of your galva­nized pipe, you can replace or extend sections with rigid copper. However, you must use a dielectric union (see the photo on p. 272) to join copper sections to steel. Otherwise, electrolysis will take place between the two metals, and cor­rosion will accelerate.

Today, galvanized pipe is largely limited to gas-supply service. Because of safety considera­tions and the difficulty of threading pipe without a power threader, have a licensed plumber install gas-supply service pipes. A plumber will install gas shutoff valves to gas-supply stubs; short lengths of flexible gas-supply pipe run from there to a fix­ture.

CPVC SUPPLY

Most plumbing codes allow CPVC for hot – and cold-water applications, but check with local authorities to be sure. CPVC is a good choice for hard-water areas, because—unlike copper— CPVC won’t be corroded by chemicals in the water. Note: CPVC is a different material from PVC, which is widely used as drain and waste pipe; PVC may not be used as supply pipe, how­ever, because it releases carcinogens.

That noted, working with CPVC supply pipe is much like cutting and joining plastic DWV pipes, explained at some length later in this chapter.

The main difference is that waste pipes are larger. Briefly, here’s how to join CPVC: Cut the pipe ends square using a plastic-pipe saw or plastic – pipe cutting shears. Clean the pipe ends as well as the inside of the fitting. Next, apply solvent – based cement to each. Insert the pipe into the fitting, turning either the pipe or the fitting a quarter turn in one direction only to spread the cement. Finally, allow the glued joints to set ade­quately before putting pressure on the line.

Before installing CPVC, make sure that you have the adapters needed to join the new plastic pipes to existing metal pipes and fixtures.

When measuring water-supply or dwv pipe runs, keep in mind that most pipe slides into fitting sockets. The depth of the socket is its seating distance (seating depth), which you must add to the face-to-face measurements between pipe fittings. When running pipe between copper fittings with a seating depth of VI in., for example, add 1 in. to the overall measurement. Rigid 3/4-in. copper fittings have a 3/4-in. seating depth.

As important, after you dry-fit pipes so fit­tings point in the correct direction, use a grease pencil or a builder’s crayon to create alignment marks on the pipes and fittings. That way you’ll be sure the fittings are pointing in the right direction when you make the final connections. Alignment marks are particularly important when cementing plastic pipe because you must turn plastic pipes one-quarter turn after inserting them into fittings; the marks tell you when to stop turning.

Socket Depths of ABS/PVC Fittings*

threaded end. A sweat/female adapter has a threaded receiving end. Adaptors are also called transition fittings because they allow a transition in joining, as just described, or a transition in pipe materials. A dielectric union can join galva­nized and copper, without the electrolytic corro­sion that usually occurs when you join dissimilar metals.

Valves are specialized fittings with moving parts. Gate valves are the most common type of shutoff valve, although lever-handled ball valves are gaining popularity because they are easier to operate. Hose bibs have a threaded outlet that you can screw a garden hose to. Angle stops are shutoff valves that control water flow to lavatories, sinks, bidets, and toilets. TPR (temperature – and pressure-relief) valves are spring-loaded safety valves that keep water heaters from exploding should the water get too hot or the tank pressure too great.

WORKING WITH COPPER SUPPLY PIPE

Type M rigid copper is the most commonly used copper supply pipe in houses, although type L, which is thicker, may also be specified. Type K, the thickest of the three, is usually specified for commercial and industrial jobs.

To cut rigid copper, place a tubing cutter on the pipe, so that its cutting wheel is perpendicular to the pipe. Score the pipe lightly at first, till the cut­ting wheel tracks in a groove. Gradually tighten the cutting jaw as you rotate the tool, until you cut through. If you tighten the tool too aggressively, you will flatten the pipe or score erratically, thus creating a weak joint.

When the cut is complete, clean the end of the pipe with the deburring attachment on the cutter so that you get a good, solid joint. Leftover burrs also increase turbulence and thus decrease flow through the pipe. Use plumber’s sand cloth or

I Pipe Fitting

When measuring pipe, allow for socket depths. Also when dry-fitting pipe assemblies, draw alignment marks on pipes and fittings to help you point the fittings in the right direction when assembled. This is particularly helpful when giving plastic fittings one – quarter turn after glue is applied.

emery paper to polish both ends of the pipe, and a round wire brush to clean the insides of fittings.

To solder copper pipe, first use a flux brush to apply self-tinning flux (soldering paste) to the outside of the pipe and the inside of the fitting. Then slide the fitting over the pipe. If the fitting is a directional fitting, such as a tee or an elbow, make sure that the fitting points in the correct direction.

Heat the fitting (not the pipe), moving the sol­dering torch so that all sides of the fitting receive heat directly. The flux will bubble. From time to time, remove the torch, and touch solder to the fitting seam. When the fitting is hot enough, the solder will liquefy when touched to it. After a few trials, you’ll know when a fitting is hot enough. When the fitting is hot, some fluxes change color, from milky brown to dull silver.

Two passes with the solder, completely around the joint, will make a tight seal; more than two passes is a waste. The solder is sucked into the joint, so don’t worry if you don’t see a thick fillet of solder around the joint. Let solder cool before putting pressure on a joint. After a soldered joint

has cooled for a minute, you can immerse it in water to cool it completely; but be careful when handling hot metal.

Soldering in tight spaces can’t always be avoided. If a fitting has several incoming pipes— at a tee, for example—try to solder all pipes at the same time. That is, reheating a fitting to add pipes will weaken earlier soldered joints. Clean and flux the pipes, insert them in the fitting, and keep the torch moving so you heat both ends of the fitting equally. If you must reheat a fitting to add a pipe later, wrap the already soldered joint in wet rags to keep its solder from melting. When soldering close to wood, wet the wood first with a plant spritzer filled with water and then use a flame shield to avoid scorching or igniting it.