Typical installations used to use steel piping. Copper tube has an internal diameter similar to that of steel, but its external diameter is significantly less. Therefore, copper's lower tubing space requirements translate into less wall damage and less restoration work after the tubing is installed. Less defacing of an historic structure, in turn, means the entire building can be sprinklered rather than just the basement and attic. And, since copper offers superior flow capacity for comparably sized steel piping, it can serve more sprinkler heads.
Copper is also lighter and easier to install.
It needs fewer hangers or clamps. Two-inch diameter Type M copper tube weighs only 2.5 pounds per lineal foot vs. 4 pounds for schedule 10 steel and 5 pounds for schedule 40 steel, according to the Copper Development Association. Copper's ductility makes bending and forming easier. The water running through copper will be cleaner because it is virtually corrosion-free. If cleaner water was discharged, it would be less damaging to all decoration and hung paintings.