Name the two most common materials used for sprinkler piping.

The two most common materials used for sprinkler piping in fire protection systems are typically black steel and CPVC. Black steel is widely used because of its strength and durability, making it suitable for a variety of conditions found in commercial and industrial applications. It can withstand high pressures and provides a solid framework for a sprinkler system.

CPVC (Chlorinated Polyvinyl Chloride) is another common material used for sprinkler piping, especially in residential applications and areas where corrosion resistance is important. CPVC handles both hot and cold water well and is lighter and easier to work with compared to metal pipes.

In this case, the combination of black steel and CPVC allows for flexibility in installation and adaptability to different environments, making them favored choices among sprinkler fitters.