# Outdoor hydrants

Hi everyone.
I am asking for help in calculating external hydrants. The designed ring network will be supplied from the DN100 water connection with the following parameters: Q = 11.40dm3 / s, H = 0.26MPa. Demand for fire protection is 1 working hydrant Q = 10dm3 / s at a pressure of H = 2 bar. I drew the network, added local losses (valve, elbows, tees, etc.). On one node I added base demand 10 dm3 / s. And here I have some questions:

1. I modeled the external network as a reservoir, set the total head as the terrain ordinate + water pressure at the connection. Is it correct?

2. How can I maintain a given pressure on an external hydrant? Can I do this with PSV Valve? If so, in what units do I provide the value of Setting? I have metric units set in my software. The hydrant should maintain a pressure of min. 2 bar, so I set the setting to 20 mH2O?

3. How can I calculate the required parameters for a connection that will meet the fire protection requirements? Q = 10dm3 / s at pressure H = 2 bar?