The capacity of the water main supplying the required Class II standpipe outlets shall be capable of supplying sufficient water to support the use of the two outlets simultaneously, each having a discharge satisfactory to the Chief, though not less than a 5/8-inch nozzle tip for the 1 1/2 inch fire hose attached to not less than 100 feet of 1 1/2 inch fire hose. The Chief may permit the use of a nozzle tip 1/8-inch less than specified. Dual purpose, fog and straight stream nozzles in standard sizes may be used when approved by the Chief. Nozzle stream horizontal reach of 50 feet shall be deemed satisfactory for straight stream nozzles.