Buying Guide

Types of Pipes

Types of Pipes
Description
PVC Pipe PVC pipes are used for cold water applications only; can warp with hot water. Keep that in mind when considering PEX vs. PVC. May be main gas line or pipes for water supply to the home and used for drain-waste-vent (DWV). Commonly used for irrigation systems. Available in rigid 10-foot and 20-foot lengths with diameters from ½ inch to 6 inches. Joins with primer and solvent cement or push-to-connect fittings.
CPVC Pipe Rigid water pipe for hot and cold water applications. CPVC pipes can be used for copper pipe replacement in residential plumbing. Available in 2-foot and 10-foot lengths with diameters of ½ inch to 1 inch. Pipe and fittings join with primer and solvent cement or push-to-connect fittings.
PEX Pipe PEX pipes often replace copper for hot and cold water pipes in residential retrofits. Considered by some to be the greatest innovation for DIY plumbers. Lightweight flexible pipes for water pipes easily maneuver around obstructions without elbow fittings. Available in 10-foot lengths or coils of 100 feet up to 500 feet with diameters of ¼ inch to 1 inch. Joins with metal crimp or push-to-connect fittings.
Copper Pipe Copper pipes are considered by many to be the standard for residential hot or cold water applications. These lightweight and durable metal pipes are available in rigid 2- and 10-foot lengths with diameters of ½ inch to 1 inch. Types of copper pipe fall into categories based on thickness of pipe wall. The thinnest, type M, is suitable for indoor water and gas applications. Thicker type L and thickest type K are used for gas service lines. Not recommended for use with natural gas in some areas as sulfur content can cause interior flaking. Joins by soldering, brazing, a compression coupler or push-to-connect fittings for water applications.
Black Pipe Strong and durable black steel pipes (a.k.a. Black Iron, Black Malleable) are used to transport natural and propane gas from the street or a tank to the home. Good for fire sprinkler systems because of heat resistance. Hub-and-spigot cast iron pipes should be installed by professionals. Comes in a variety of lengths from 2 inches to 10 feet and diameters of ¼ inch to 2 inches.
Galvanized Pipe Galvanized pipes are used for water supply lines, well pump and some irrigation applications. They are dipped in zinc during manufacturing process to prevent corrosion. Galvanized pipes are rarely used in new home construction now but were common until 1960s. Various lengths from 18 inches to 10 feet with diameters of ½ inch to 2 inches.
CSST Pipe CSST tubing, or corrugated stainless steel tubing, is good for installing gas appliances. These corrugated pipes can bend around corners reducing the number of joints and fittings. Easier to work with than steel pipe and weighs a lot less. Certification through manufacturer is recommended before installing CSST.
Polyethylene Pipe Polyethylene pipes are used in a wide range of pipes for drainage, irrigation, water service and even some varieties for underground gas transport. It is durable and provides long-term resistance to environmental conditions in outdoor and underground uses. Pipe and fittings join with primer and solvent.
ABS Pipe ABS pipes are used for drain, waste and vent (DWV) applications. The material (acrylonitrile butadiene styrene) ABS pipes are made from can withstand higher temperature drain water than PVC pipe. Pipe and fittings join with primer and solvent.
Measuring Pipe Sizes
Calipers measure the inside diameter of a pipe.

There are several dimensional standards for all types of pipes and it is important that you know the exact size pipe you need before installation.


For replacement jobs, where you need a new pipe to exactly match the damaged one, use calipers or a tape measure. Place the calipers on the outside edges of the pipe or lay the the tape measure over the opening at the end of the pipe, straight across the middle of the hole where it’s the widest. Measure from outside edge to outside edge to give you the width of the pipe, including the pipe material itself. That is your outside diameter, or OD.


Now, measure across the center of the pipe again, but this time from inner edge of the material to inner edge to measure the actual opening of the pipe. That is your inside diameter, or ID.


Armed with these two measurements and the types of pipes needed, you can correctly select the replacement piping.


Tip: Always check local code requirements to confirm that the materials you select meet required standards. If you're not sure of the correct size or grade when replacing pipe, bring it to your local Home Depot store so that it can be matched.

Tools and Supplies For Working With Pipes

In addition to the materials needed to join your pipes and fittings together, you can make your job easier with some basic pipe cutting tools, hangers and caps.


Cutting tools: Tubing cutters will help you slice through plastic pipes with ease while a rachet soil pipe cutter will make short work of cast iron waste pipes. Turn-to-cut copper tubing cutters automatically tighten the cutting wheel to make clean cuts on hard copper.


Hangers: Horizontal pipes need support every 4 to 6 feet, so you'll need to install pipe hangers. Types of hangers include wire hooks, copper two-hole straps, plastic hangers and plumber’s straps. Always follow local code requirements.


Water hammer arresters: Also called mufflers, these devices stop the banging sound you hear when valves on washing machines, dishwashers and faucets slam shut. They also help prevent damage to both pipes and faucets.


Vents and traps: Vents filter air and gas out of plumbing pipes as well as provide air to help water flow. Traps are installed below sinks and keep sewer gases and other noxious vapors out of your house.


Caps: Pipe caps allow you to temporarily seal off the end of a pipe so you can turn the water back on for the rest of your plumbing system.