Improving NPSH

Félicien Gebel and Stéphane Boeglin, Fives Cryomec, Switzerland, present a new inducer design in the LNG Industry August 2017 edition.

When dealing with cryogenic fluids, such as nitrogen, oxygen, argon or LNG, which have boiling points at less than -150°C, net positive suction head (NPSH) improvement is an important topic. Keeping the NPSH under control is a key asset to avoid cavitation in cryogenic pumps. These fluids are often prone to evaporation, which can lead to a premature wear. Cavitation can also have other immediate negative consequences on pumps, such as vibration, gases development and instability.