Home > SuperTips > Plumbing > Types of Plumbing Pipes
Rheem Water Heaters
Affordable & efficient commercial & residential hot water solutions.

Plumbing & Heating Contractors
Local Plumbing & Heating Contractors in your area

Licensed Plumbing Contractors
Local Licensed Plumbing Contractors in your area

Plumbing Contractors
Local Plumbing Contractors in your area

Get Quotes from Top Rated Plumbers!
Get bids from HomeAdvisor 10-Point Screened Plumbers. Free Service

Pipe Cleaning Service
Pipe Cleaning Estimates, Customer Reviews, Profile Info & More!

SuperTips Categories

Share This:

Types of Plumbing Pipes

Plumbing Drain & Sewer Consultants
Plumbing Service Estimates, Customer Reviews, Profile Info & More!

Plumbing pipes come in a broad array of materials. Many kinds are in use today, both old and new types, constructed from an assortment of metals and plastics. Some are better suited for particular applications than other. Here's an explanation what each type can do, and what its limitations are.

For all their variety, all plumbing pipes fall into into two major categories: metal and plastic.

Metal pipes

Copper Used since the early 1960s and very reliable, but expensive. Highly resistant to corrosion and tolerant of heat. Not prone to leaks, since its connections are soldered and fittings stay tight. Copper pipe comes in three sizes: M (very thin walls), L (medium thickness) and K (thickest walls). Types M and L are usually used for interior hot and cold supply lines while Type K serves for underground service lines. Copper pipe's biggest drawback is price, and because of its value it's also an attractive target for thieves. Soldering fittings requires some skill, and cuts must be precise. It can split when frozen. Copper is gradually being replaced by more economical plastic pipe.

Galvanized Steel Gray metal pipes that most of us think of when we think of plumbing. They were used extensively in home plumbing in the 1960s, particularly outdoors. They were often buried, and used as supply lines. Galvanized steel is only slightly resistant to corrosion and rust, and has a life expectancy of about forty years. They are usually replaced with copper or, more often, PEX and HDPE pipe in home plumbing.

Stainless Steel Not seen as often in household use. Stainless steel pipes are strong and highly resistant to corrosion, but even more expensive than copper pipes. They're used in marine environments where salt water would erode other metal pipes.

Cast Iron Frequently used in the past for drainage. It's very durable, but difficult to work with because of weight. If you need to replace broken cast iron pipe, PVC is a good choice because it joins well with cast iron.

Black Iron Not used for plumbing! Sometimes mistaken for plumbing pipes, black iron pipe is only suitable for carrying gas, not water.

Plastic pipes

Grey Plastic Polybutylene (PB; also referred to by the brand name Quest) Gray or beige, usually sold in coils. Flexible pipe used extensively from the late '70s to the mid '90s. It was an inexpensive replacement for copper. Over the years, however, PB has proven to be prone to leaks. It's very easy to install, with joints secured by epoxy or slip fittings and metal crimp rings. Approved for both cold and hot service lines.

Creamy Plastic Chlorinated Polyvinyl Chloride (CPVC) Another substitute for copper. Yellowish or beige in color, it's PVC pipe that has been given extra chlorination. More reliable than PB, less expensive and easier to install than copper, it can be used for cold and hot water supply. It's more flexible than PVC, but should not be buried. It will split if it freezes.

Polyvinyl Chloride (PVC) White or grey pipe used most often to carry high pressure water. Not for use with hot water, which can cause the pipe to warp, but often used for the main supply line into a home. If you use PVC for a supply line, make sure it's approved for drinking water. Many PVC-DWV (drainage, waste and vent) pipes are also white but should not be used for water supply. PVC comes in sizes ranging from 1/2” to 4” in diameter. Inexpensive and very easy to work with.

Cross Linked Polyethylene (PEX) Used extensively for interior plumbing in new homes. Easy to install, with the same straightforward fittings as PB. Used for hot water as well as cold. In fact, PEX resists heat much better than most plastic pipe so it's often used for water-based heating systems. Comes in white, blue or red.

Acrylonitrite-butadiene-styrene (ABS) Black plastic drainage, waste and vent pipe. ABS is rigid plastic that connects easily to metal pipe. It was a forerunner to PVC, and is prohibited by many current plumbing codes. Not uncommon in mobile homes. Replace with PVC or HDPE.

High density polyethylene (HDPE) Highly resistant to corrosion, flexible and very long lasting. It's used to carry everything from drinking water to compressed gas to hazardous waste. HDPE comes in long lengths, and joints are formed through heat fusion, eliminating leaks. It has unusually low resistance, or drag, making it a good choice for virtually all plumbing applications.

When you make modifications or perform repairs to your household plumbing, use the same type of pipe as the original. If that's not possible, pick a comparable type, suitable for your purpose, that will work with your existing pipe. Make sure you understand the advantages and limitations of each type of plumbing pipe, and you'll be able to choose what's best for your job.

Find local Plumbing Resources