I think EPAnet is the tool to use for comparing actual vs calculated. I don't believe there's a test method to compare these values with the results of EPAnet. You'll have to do some hand calcs to compare. In my opinion, this program is best tested by running the program and comparing with known results such as you did at the fire hydrants. Have you input the data for the items which will cause pressure in the system (ie pumps and reservoir elevations, prv information, flow rate)? You'll need to check known pressures at nodes to determine if you have entered the pressure causing items correctly. For example, there are different methods of entering pumps and reservoirs. You input PRV's in the input file. If you've got the input data correct, such as pump, flow, and reservoir level, etc., the pressure at the hydrants should be close to the known pressure value.