Pipe Flow Expert Software Example Systems - Common 05 – Enlargements & Contractions

Figure 5  Common 05– Enlargements & Contractions

When two pipes of different diameters are joined there will be some pressure loss across the junction because the fluid velocity will change. 

The Pipe Flow Expert database includes fittings 'K' factor calculators for:

Sudden enlargements, where a smaller pipe feeds into a larger pipe.

Sudden contractions, where a larger pipe feeds into a smaller pipe.

Gradual enlargements, where a smaller pipe expands gradually to the larger pipe size.

Gradual contractions, where a larger pipe expands contracts to the smaller pipe size.

The 'K' factor is calculated based on the internal diameters of the connecting pipes and the length of the fitting (in the case of gradual enlargements or gradual contractions).

The 'K' factor and the fluid velocity in the ENTERING pipe allow the head loss across the joint to be calculated.