Which calculations must show that a main can supply the total flow rate at the design pressure?

Hydraulic calculations are essential in determining whether a fire service main can adequately supply the required flow rate while maintaining the design pressure. These calculations take into account various factors such as pipe diameter, length, material, fittings, and the specific characteristics of the fluid being conveyed.

By performing hydraulic calculations, engineers can simulate the flow conditions within the system, ensuring that it will perform as intended under emergency situations when necessary. They assess the pressure losses due to friction and other factors, ultimately confirming that the fire service main can deliver the required water flow at the specified pressure level that is safe and effective for firefighting purposes.

The other testing options, while important in their own right, serve different purposes. Flow tests measure the actual flow rate capability of a water supply, flushing tests are conducted to clear the system of debris, and hydrostatic tests are used to check for leaks and the integrity of the piping under pressure. However, none of these directly address the need to calculate and confirm that the main can support the required flow at the designated pressure within the design parameters.