Design and Analysis of Gating and Risering System for Casting of Ball Valves

Abstract

Casting is suitable economical manufacturing process for various components. It may experience different defects such as crack, porosity, hot tear etc. because of poor design of gating and risering system. The objective of the project is to optimize gating and risering systems of ball valve component based on CAD and simulation technology with the goal of improving casting quality and increasing casting yield.

In the work presented, CAD model of ball valve has been developed and simulation has been carried out using ProCAST. ProCAST results are compared with the experimental results for validation. Risering and gating parameters are modified to get better yield. It is observed that with new gating and risering system casting yield is improved by 8% and porosity is decreased by 1%.

It is required that manufactured ball valves must have minimum 650 MPa tensile strength. It is observed that the tensile strength obtained is 588 MPa which is less than the desired. Some changes in the heat treatment cycle were carried out. After heat treating as per the modified heat treatment cycle the tensile strength was obtained to be 678 MPa. This is because of percentage of martensite formed is higher in the modified heat treatment cycle, which was reveled after observation of optical microscope.