TWO-K METHOD PREDICTS HEAD LOSSES IN PIPE FITTINGS.

Forcing a fluid through a pipe fitting consumes energy, which is provided by a drop in pressure across the fitting. This pressure drop - or head loss - is caused by friction between the fluid and the fitting wall and by creation of turbulence in the body of the fluid. The loss due to wall friction is best handled by treating the fitting as a piece of straight pipe, of the same physical length as the fitting. All common prediction methods, and the two-K method, do this. But each method predicts the remaining ″excess″ head loss a different way. This paper describes a new technique that requires only two constants, plus the Reynolds number and fitting diameter, to predict the head loss in an elbow, valve or tee. It is accurate even for large-diameter and alloy fittings, and at low Reynolds numbers.