Reference:  Cameron Hydraulic Data , 18th Edition, 1994, Ingersoll-Dresser Pumps. Page 1-15, Example No 4.


Pipe Flow Expert File: Case_15_Water_Net_Positive_Suction_Head_Available.pfe


Problem Description: 

A pump is used to deliver water to a distribution system.

The friction loss through the suction line is stated to be 2.92 ft head.


The water source is 10 ft above the pump.

The fluid is contained in a closed vessel which is under pressure.


The pressure on the surface of the fluid is 119.90 psig.


Find the NPSHa and the suction head available.


A screenshot of a computer??Description automatically generated


Fluid Data: Water at 350°F, with specific gravity of 0.8904 and a vapor pressure of 134.60 psi.a.


Result Comparison: 


Data Item 

Published data

Pipe Flow Expert

NPSH available ()

7.08

7.07

Suction Head ()

317.69 (positive)

318.31 HGL at pump


Commentary: 

The published data and the calculated results compare well.

This is a very simple example where the friction loss through the pipes is stated.

To model this situation in Pipe Flow Expert pipe diameters and pipe lengths have been set to give a total friction loss in the suction pipes of 2.92 ft hd, when the pump flow rate is set to 5 ft³/sec.

The discharge pipework was modeled with a similar size pipe and a 10 ft lift on the discharge side of the pump to a required delivery pressure of 200 psi.g.

This allows the HGL at the node where the pump has been located to be used for comparison with the published suction head available.