Pipes are available in a variety of materials, sizes, and weights. The type selected for a particular installation will depend on a number of factors, including government codes and standards, specifications, system requirements, availability of materials, and cost. Some of these factors, such as codes and standards, will have priorities over others, but all should be given equal consideration before deciding which pipe to use. The purpose of this chapter is to offer some guidance for making these decisions.
Types of Pipe Materials
The materials used in the manufacture of piping and tubing for steam and hydronic heating systems include the following:
• Wrought iron
• Wrought steel
• Galvanized steel
• Copper, brass, and bronze
• Plastic
• Synthetic rubber
• Composites
Steel piping leads in popularity and is available in the form of either wrought steel or galvanized steel. Wrought-iron and cast-iron pipe are also used, but less frequently because of their higher cost. Copper and brass are employed in the manufacture of both pipes and tubes and find their greatest application in radiant panel heat- ing, air-conditioning, and refrigeration systems. Other metals (for example, aluminum, bronze, and alloy metals) have also been used in the manufacture of this pipe, but with limited application due to cost, lack of availability, and other factors. In addition to steel and copper tubing, modern hydronic heating systems also commonly use plastic tubing (cross-linked polyethylene or polybutylene), synthetic rubber hose, and composite tubing.
Note
The terms pipe or piping and tube or tubing are sometimes used interchangeably, especially when referring to the piping/tubing systems of hydronic radiant panel heating systems. See Copper and Brass Piping and Tubing in this chapter.
This chapter concentrates on a description of iron, steel, copper, and brass pipes; the various types of nonmetal tubing; the pipe fit- tings used with them; and the methods employed in installing them.