Sprinkler K Value Coefficients
Many manufacturers of spray nozzles publish a Sprinkler K value to describe the flow / pressure loss characteristics of their spray nozzle in a standardized manner.
Sprinkler K Value Coefficient:
A sprinkler K value can describe the sprinkler performance in either imperial or metric flow rates (there is a metric K value and an imperial K value for the same sprinkler and these will be different values, hence it is important to check a sprinkler K value to confirm if it is a metric value or an imperial value).
The imperial sprinkler K value is calculated as follows:
The metric sprinkler K value is calculated as follows:
The imperial and metric Sprinkler K values are not interchangeable. When a Sprinkler K value is used for a flow versus pressure drop calculation, it is important to know if the value specified is based on the imperial formula or the metric formula, since this will affect the calculated results.
When a pipe diameter is known it is possible to establish a flow velocity from the Sprinkler K Value for a particular pressure drop and therefore it is possible to calculate an equivalent fitting ‘K’ factor which will produce the same pressure loss as the Sprinkler K Value.
Pipe Flow Expert uses the equivalent fitting ‘K’ factor method to model the flow and pressure loss through a spray nozzle where a Sprinkler K Value is used to specify the nozzle characteristics.
A change to the pipe diameter will result in a change to the matching equivalent fitting ‘K’ factor.
Pipe Flow Expert re-calculates the equivalent fitting ‘K’ factor for the current pipe diameter using the fluid density of water.