A vertical pipe is a type of plumbing fixture that is used to connect two pipes together. The crossword solutions for this term are RISER (5 letters), JAMB (4 letters), and PLUMB (5 letters). A RISER is a vertical pipe that connects two horizontal pipes, while a JAMB is a vertical pipe that connects two vertical pipes. PLUMB is a term used to describe the alignment of a vertical pipe, meaning it is perfectly straight and vertical.