For corner taps Reynolds number must be greater than 10,000 for greater than 0.45. For less than 0.45, the Reynolds number must be greater than 5,000. The fourth term introduces Reynolds number effect. Although the equation appears to give a coefficient value for all tapping locations, standardized or not, it was not developed with data for other than standard locations and, therefore, is not recommended for nonstandard tapping locations. The coefficients by this equation are substantially the same as found in older presentations.
Differences come mainly from the data fitting method.
The equation which relates flow rate to head differential and other parameters may seem to be rather complicated but is a minor inconvenience with modern computer capabilities.