Stress qualifications for standard and nonstandard valves in piping systems

摘要

Various types of valves are used in refineries, petrochemical plants, fertilizer plants and utilities. As a part of a low-or high-pressure/temperature piping system, these valves are subjected to fluid pressure/temperature, as well as to external loads from a connected piping system. A design engineer should perform a stress analysis of stress-critical piping systems for qualifying the piping system (including fittings, valves, etc.), as per applicable design codes. An approach is defined here to highlight the requirements for stress qualification of the standard pressure-temperature (P-T) rating for nonstandard valves, either individually or as part of piping system in which they are installed.