Fitness-for-Service of Pressure Relieving Systems

Fitness-for-service assessments most commonly have been applied to tanks and pressure vessels. However, fitness-for-service evaluations are applicable to virtually all equipment, piping and hardware in an operating facility that, upon failure, would result in economic loss of equipment or production, exposure of plant personnel to hazardous conditions, toxic or hazardous releases to the environment, and/or risk to public safety. Federal and state regulations require operating industrial facilities to have risk management programs in place that include the design basis for safety-relief systems installed to protect pressurized equipment from overpressure. For process facilities that have been in operation for many years, the original design basis and calculations for the safety-relief devices often are no longer available. A fitness-for-service assessment of an existing pressure relieving system includes verification of the relief device size and specification, and review and substantiation of required documentation. This paper presents the required elements of a pressure relieving system size verification and documentation program for existing process facilities. The required technical information to perform a fitness-for-service assessment is described. Some restrictions and limitations of the codes and standards that are applied for design guidance of pressure relieving systems are challenged [5–13].Copyright © 2003 by ASME