I have a network of stainless steel pipes that are distributing water throughout a building.

I know the flow rate of water entering the system is 600 IGPM, but am unsure of how this water will be distributed. I have attached a simplified schematic of what the pipe network looks like. enter image description here

Is it safe to assume the flow rate throughout this network will be the same, even though the diameters change, based on the continuity equation?

A1*V1 = A2*V2
  • $\begingroup$ No, changing diameters will have an effect, as will the different lengths and how many bends there are as they all add losses in terms of pressure drop or head. $\endgroup$ – Solar Mike Jan 29 at 18:56

The flow rate through the network will most definitely not change only with the area of the pipes.

As water flows through a system, its pressure (often referred to as head) is reduced by friction along the way and changes in elevation.

Pipe friction is a function of pipe diameter, pipe length, fluid characteristics, and pipe wall smoothness. Every bend in a pipe also introduces additional head loss. The head loss due to this directly affects the flow rate through the pipe.

But the key thing that will affect flow through the network is the usage by each end user. I doubt that these pipes just empty into rooms. So the flows in each branch pipe will be determined by the outlet of the pipes. In a non-industrial use we can probably assume that water requirements fluctuate greatly. For industrial use we can determine flows by direct measurement (buckets, etc), or flow measurement devices in the pipes. If we had static pressures throughout the system we might be able to back in to flows, given that we know the total. I feel like this might have to be an iterative process.

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  • $\begingroup$ You could add the Moody chart... $\endgroup$ – Solar Mike Jan 30 at 6:42

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