Analisis Pengaruh Kavitasi pada Pompa Sentrifugal Graving Dock

Abstract

Centrifugal pump at the graving dock experienced cavitation. It caused noise and a damage
to its impeller as vapor bubbles appeared around it. This problem caused the centrifugal pump’s power
decreased. The research method to solve it is collecting, calculating, and analyzing data. The
calculations analyzed are the calculation of velocity, friction factor, head losses, pump head, NPSHA
and NPSHR values. If NPSHA value is less than NPSHR, the pump is cavitated and modification to the
piping system is needed so that the cavitation problem can be overcomed. The NPSHA calculation
result is 4.77 m while the NPSHR is 6 m so that the it can be concluded that the pump experienced
cavitation. Based on these calculations, modification of its centrifugal pump piping system is required.
The pump which was originally had a suction pipe length of 6 meters was shortened to 5 meters. The
pump position was lowered so that the suction pipe could reach the lowest water level at the graving
dock. The pipe diameter of 0.3 meters was enlarged to 0.4 meters. After modification, the NPSHA value
exceeds the NPSHR by 0.7 meters so that the centrifugal pump will be safe from cavitation.