Integration of Hydraulic Studies in Evaluating Abnormal Plant Conditions during Commissioning and Startup, Maintenance, and Intermittent Operations

Multiple abnormal operating circumstances are encountered in various phases of plant life cycle. During commissioning, maintenance, and irregular batch operations, challenges arise which may prevent in achieving an objective in differing modes of operation. Underestimated more often than not, a common operating problem boils down to issues of fluid transfer of process systems.

In aid of continued operation, hydraulic calculations were performed to attend on familiar dilemmas in a petrochemical plant. In the first case, simulation was utilized to determine viability of a proposed relief alternative pathway during a preventive-maintenance removal of a pressure safety valve (PSV). On the other hand, a separate calculation was also carried out to evaluate a proposal to remove a blower from a series of two units during commissioning of a project-delayed combustible dusts venting system. Lastly, a hydraulic analysis addressed an abnormal high pressure build-up and high flow in an intermittent recipe requirement of a corrosive chemical in a batch process.

The three scenarios are illustrations of process modifications in abnormal modes of operations and in atypical operating conditions. If not decided with a sound technical judgment, process changes may induce operational and safety consequences affecting property and people. The study demonstrates the effectiveness of conducting hydraulic checks to recommend solutions or to assess proposal as part of the management of change proceedings. Based on the calculation summary, key recommendations were generated and implemented accordingly to assist requirements in varying plant conditions.