Standard K fittings use pre-determined loss coefficients that represent the head loss associated with a particular fitting size and configuration.  Each K value corresponds to a specific fitting type and dimension and does not vary with flow rate or Reynolds number.  These K values are defined directly and they provide a simple and reliable means of modelling fittings where a constant loss coefficient is appropriate.


The Standard K library includes a broad range of fittings commonly used in engineering applications.  For each fitting, the Pipe Flow Expert database defines the K values.

NOTE: Choose a Fitting size that matches the size of the Pipe.  For example, if you are using a 4” nominal pipe size, select either a 100mm or a 4” Fitting.


Figure 67  Fitting Data Screen – Standard K Fittings


Interpolated Standard K Fittings


When Standard K fittings are not available for the selected pipe nominal size (for example, a 5/8 inch pipe where no 5/8 inch fittings exist in the Fitting Database), Pipe Flow Expert can create interpolated fittings by estimating an equivalent Standard K loss coefficient.  


Section: Calculation Theory and Method of Solution > Interpolated Standard K for the formula and further information.


When displaying the Fitting Data screen for a pipe whose nominal size does not have any corresponding fittings, the Fittings Database will show interpolated fittings for the current pipe size.



Figure 68  Interpolated Standard K – Fitting Data Screen – Fitting Database

Clicking will display an information panel that provides further details about interpolated Standard K Fittings.