“…The design importance of water supply networks inside buildings has emerged to provide the daily demand for water for drinking, cooking, showering, and various activities, the design is depends mainly on calculating the demand of water consumed and the appropriate pressure for operation [3], the process of calculating the water demand for the design of water supply networks inside buildings is 1222 (2023) 012006 IOP Publishing doi:10.1088/1755-1315/1222/1/012006 2 depending on the Hunter curve method [4], which depends in its calculations on giving each fixture in the network a numerical value that depends on the fixture's consumption of water simultaneously, this value is called the Fixture Unit and by using Hunter curve to find the water demand of building [5]. The appropriate design pressure value for the water supply network inside the building to exceed the height difference between the water source in the network and the highest fixture in the network, the network operating pressure value represents the pipes friction losses in the network, and the pressure required to operate the fixtures, [6], depending on the procedures in the global or local codes like (The American Society of Plumbing Engineers (ASPE), Uniform Plumbing Code, National Standard Plumbing Code, International Building Code (IBC), International Plumbing Code (IPC)) and using the values extracted from the water demand calculations and the design pressure to operate the water supply network inside the building, the sizes of the parts of the network are calculated such as tanks, pipes, fitting and also the pumps discharge and head [7].…”