45 feet of horizontal piping is run from a tee in the fire sprinkler system crossmain to supply a 1-1/2 inch hose. The minimum size pipe that may be used is ____ inch.

45 feet of horizontal piping is run from a tee in the fire sprinkler system crossmain to supply a 1-1/2 inch hose. The minimum size pipe that may be used is ____ inch.