Abstract: This paper discusses the problems in the design, selection and operation of balanced bellows pressure relief valves in hazardous environment, and clarifies how to correctly handle the vent on the valve cover of balanced bellows pressure relief valve in view of its particularities in process design and guarantee the correctness of design, selection and hazardous area classification, so as to eventually eliminate the potential risks and ensure the safety and reliability of balanced bellows pressure relief valves

Key words: Pressure relief valve, Balanced bellows, Safety