Investigation on Centrifugal Pump Shaft: A Comparison Study of the SME and the Imported Product

Abstract

The implementation of the ASEAN-China Free Trade Agreement (ACFTA) forces the small and medium enterprises to have a high competition between the manufacturer from China and the ASEAN member countries. One of the competitions occurs on the market of centrifugal pump for fisherman ship. The SME product, made in Tegal, has a lower price but also has a short lifespan. The imported product is now preferred by the fisherman due to its better performance and its longer lifespan. The main problem of the SME pump comes from the excessive wear at the pump shaft, indicated by a collection of deep scratch at two locations in pump shaft. This paper investigates the cause of the excessive wear at the SME pump shaft and compares the quality of the SME and imported shaft by conducting material characterization, mechanical testing, and design evaluations. The chemical composition, hardness property, tensile strength, geometrical analysis and bearing design of the both shaft products are compared. Results show that the SME product uses a higher quality material shaft but ignores the good engineering design in developing the fisherman pump shaft product. The absence of the bearing mounting design on the shaft, the lack of lubricant volume and the low quality of the seals on the SME pump product induce the undesirable wear on the pump shaft. The improvement of the shaft design is required to increase the quality of the SME pump.