Development and validation of a leak before break criterion for cylindrical pressure vessels

Abstract

Leak before break is a fail-safe design concept for application in pressure vessels and piping of power and process plants. A quantitative maximum allowable flaw size is required to establish to set acceptance/rejection limit to predict whether the specific cracked pipe will leak or break. A new modification and its boundary based on Modified Two Parameter Fracture Criterion is capable of separating the leak and break cases distinctly in order to predict the behavior of cracked cylinders, pipelines and pressure vessels in advance for taking necessary precautions by the plant operator and also very much handy for the designers. For the given operating pressure under the observed crack dimensions, whether the crack will leak or break can be assessed from the boundary generated for the material concerned using Modified Two Parameter fracture assessment procedure.