A useful research report has been published by ODPM to provide information on the limitations of fire rising mains such as wet and dry risers complying with BS 5306 part 1: 2006. The report looks at a number of different pumps and nozzle and hydraulic calculates the pressure loss through the pipe.
The Canute - FHC hydraulic calculation software is able to make the same types of pressure loss calculations as presented in this report which may help installers and designs verify designs.
You can get a full copy of the ‘Hydraulic Calculation of Wet and Dry Risers, Hoses and Branches' bellow