Leakage analysis on zero offset butterfly valves with rubber seat type focusing on rubber seat reliability

Abstract

This study aims to identify and analyze the damage mechanism of EPDM elastomer seat which is the root cause of leakage in zero offset butterfly valve. The research method involves direct sealing leak test on butterfly valve with EPDM rubber seat from two different suppliers, accompanied by measurement of material hardness. ANOVA analysis is used to highlight the difference in hardness between suppliers, while Firth Logistic Regression is applied to predict the probability of leakage based on temperature, supplier, and hardness variables. The results show that operating temperature is the dominant factor affecting leakage, while variations in hardness and supplier quality factors still play a supporting role. Too high hardness causes loss of elastomer elasticity at low temperatures (-20°C), thus increasing the risk of leakage. This study produces technical guidelines in the form of supplier evaluation with leak test standards at extreme temperatures and hardness control within the optimal range. This research and testing provide direct contributions to the industry in ensuring the quality of zero offset butterflies produced and reducing costs due to operational failures.