WaterCAD Fire Flow Analysis Problem

[jahodges01]

I ran a fire flow analysis on my WaterCAD model and cannot attain any available fire flow to any nodes in the system (0 gpm) thus not satisfying the flow constraints of 1,500 gpm. Does anyone know why I would have 0 gpm available fire flow throughout the entire system, would this have to do with assigning zones to respective nodes? I have everything set at 1 zone....please help!

Thank you

 

[theci]

You must have at least one node that gives you a pressure lower than your constraint pressure under steady state analysis (without fire flow analysis). You have to run fire flow analysis without that node. To know which node has low pressure, simply run steady statle analysis (without fire flow) and see which node is less than your constraint pressure. In your fire flow analysis, you may have to take that node out otherwise no available fire flow will be assigned to all other nodes because they all can not satisfy the pressure constraint of the low pressure node.

theci

 

[CrazyHorse81]

I would run my base scenario as the average daily demand and assign flows at each node respectively. Then I would recommend designating a child scenario with the average daily peak monthly flows associated with each node. Finally, I would create another (2) child scenarios with the ADPM. The first fire flow node being the high point node and the second fire flow at the furthest node downstream.

So in all I would have one base, and three child scenarios...
ADD
ADPM
ADPM + FF1
ADPM + FF2

Enjoy!