Abstract: As an important safety device, safety valves are widely applied in various industrial fields. They play a key role in ensuring the safety of equipment and people. This paper presents in detail the application of safety valves in chemical industry, and discusses the methods to correctly calculate and select safety valves under the requirements of specific working conditions and media characteristics. Through an in-depth analysis of the type, operating principle, calculation method and selection criteria of safety valves, practical recommendations are provided to ensure the safe operation of the plants. This paper also discusses the calculation of safety valves in two-phase flow fluid. By comparing the venting areas of the gas-liquid phase from separate calculation and calculationby the omega method, a relatively reliable basis for selection is derived, which can provide reference for the design of safety valves in similar process devices in the future.

Key words: chemical industry, safety valves, type selection and design, two-phase flow fluid calculation