Reference:  Flow of Fluids – Technical Paper No 410M, 1999, Crane Co. Page 4-8, Example 4-14.


Pipe Flow Expert File: Case_29_Water_Bernoullis_Theorem.pfe


Problem Description:

A piping system consisting of 4” and 5” diameter schedule 40 steel pipe carries water at a flow rate of 1500 l/min.


The change in elevation across the system is 22.0 meters.


Find the fluid velocity in the 4” and 5” steel pipes and the pressure difference between the inlet and outlet points of the system.


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Fluid Data: Water at 15°C


Result Comparison: 


Data Item

Published data

Pipe Flow Expert

Pressure difference across the system (bar)

2.60 

2.6266 (3.000 – 0.3734)

Fluid velocity in 4” diameter pipe (m/s)

3.04

3.044

Fluid velocity in 5” diameter pipe (m/s)

1.94

1.937


Commentary: 

The published data and the calculated results compare well.

The system was modeled in Pipe Flow Expert with a fluid surface pressure of 3.00 bar g at the inlet to the system. 

The outlet node had a resulting pressure of 0.3725 bar g.

The pressure difference is obtained by subtracting the outlet pressure from the inlet pressure.