The fitting loss for a straight-through flow in a tee or cross during branch line calculations is treated how?

When considering fitting losses in the context of sprinkler systems, particularly for a straight-through flow in a tee or cross, the critical aspect is understanding how this loss is accounted for in hydraulic calculations. In this case, fitting losses for straight-through flows are often not included in the calculations.

This is primarily because fittings like tees and crosses, when configured for straight-through flow, do not significantly disrupt the flow regime in the same way as they do for branch flows entering at an angle. The assumption is that the velocity and pressure drop through these fittings can be negligible for straight flow; hence, they can be omitted from detailed demand calculations.

In a practical sense, this approach simplifies the calculations for designers and engineers, allowing them to focus on the most pertinent aspects of system hydraulics without overcomplicating the model with minor losses that have minimal effect on the overall performance of the sprinkler system in straight-through configurations. Thus, the treatment of fitting loss in this case is seen as not necessary to include in the total hydraulic demand calculations.