Introduction: The coefficient of Contraction is defined as:
Where is the area of the choke and is the area of the pipe. The head lost is given by:
k Is a constant and in this case is approximately 0.5. The value of varies with the application and a selection are shown in the table at the end of this section.
Loss of head is given by:
Head Lost at an Obstruction (e.g. A Valve)
The formula from above hold good but with differing values for K. The following table gives some typical values: