Cavitation analysis in a re-designed direct acting pressure relief valve through flow visualization method

This research investigates the cavitation wear phenomena in a direct-acting pressure relief valve (PRV), where the poppet of the PRV is subjected to unseat at over-pressure conditions of the hydraulic system. The poppet unseat results in to sudden fall in system pressure and hence, the expansion and burst of pre-existing tiny air bubbles and thus the cavitation. To reduce the occurrence of cavitation, three different poppet shapes i.e. chamfered conical, blunt, and spherical heads is proposed for replacement over the existing conical head. To investigate the effect of different poppet shapes, the CFD simulation of the simplified 2-D fluid flow geometry is considered and the same is validated through experiments. Further, the validated model is used to investigate the cavitation parameters during the PRV operation at different opening conditions. The results showed that the blunt head PRV poppet offers comparatively lesser cavitation intensity for hydraulic systems subjected to frequent over-pressure conditions.