LARGEST SIZE STEEL PIPE REQUIRED IN A PIPE SYSTEM RISER TO SUPPLY 4 FIRE SPRINKLERS ON EACH OF 7 LEVELS IN THE STAIRWELL OF AN ORDINARY HAZARD OCCUPANCY IS____.

LARGEST SIZE STEEL PIPE REQUIRED IN A PIPE SYSTEM RISER TO SUPPLY 4 FIRE SPRINKLERS ON EACH OF 7 LEVELS IN THE STAIRWELL OF AN ORDINARY HAZARD OCCUPANCY IS____.