Awater fountain is to be installed at a remote location by attaching a cast iron pipe directly to a water main through which water is flowing at 70°f and 60 psig. the entrance to the pipe is sharp-edged, and the 70-ft-long piping system involves three 90° miter bends without vanes, a fully open gate valve, and an angle valve with a loss coefficient of 5 when fully open. if the system is to provide water at a rate of 15 gal/min and the elevation difference between the pipe and the fountain is negligible, determine the minimum diameter of the piping system.