Problem 4.2.5

Water is flowing through an 8-inch pipe diameter pipe at a rate of 2.23 cubic foot per second. A square-edged orifice plate (5.75-inch) is installed in the pipe. What manometer reading in inches of mercury would be expected?

Solution:

Velocity in the main pipe, based upon d₂, is 6.419 foot per second. That yields Reynolds number of 8.97 timea10⁵. For beta (d₁ over d₂) of 0.721, orifice coefficient can be read as 0.70.

Using orifice area, A1, as 0.181 ft², pressure drop is found to be 295 pounds per square foot.

Manometer deflection could be calculated as 0.375 foot or 4.5 inch of mercury.