Which component is defined as a pipe that rises vertically and supplies a single sprinkler?

The correct answer is the sprig. A sprig is specifically defined as a short pipe that ascends vertically from a main line or a branch line to supply a single sprinkler. Its primary function is to create a direct water supply connection to an individual sprinkler head, ensuring that the sprinkler can operate effectively when activated.

Other components like a riser and system riser typically refer to larger vertical pipes that support and distribute water throughout a system rather than solely supplying a single sprinkler. The riser nipple acts as a connecting piece but does not rise to supply water by itself. Understanding these specific definitions in the context of fire protection systems is crucial for efficient sprinkler system design and installation.