Evolving industry guidelines are changing the way Oil & Gas companies approach process safety in pressure relief, blowdown and flare systems. Best practice now increasingly puts high accuracy dynamic modeling techniques at the center of materials of construction decisions and flare capacity assessments. The 6th edition of API 521 recommends greater attention is given to low temperature embrittlement risks in both the process equipment and the flare system during process blowdown.

In conventional screening methods, calculations of safe design temperatures are based on analysis of a single pseudo-vessel with simplified representations of thermodynamics and heat transfer. Such methods are no longer seen as providing either the necessary assurance for safe operation or the required information for making capital expenditure decisions.

In this presentation we discuss a rigorous approach, using distributed blowdown system models, to assess risks of cold temperature brittle fracture during process depressurization. We highlight the important benefits of this approach and when it should be applied, and discuss how it fits into existing engineering workflows and how it is aligned with the changing industry guidelines.


Apostolos Giovanoglou is the Technical Director of PSE Oil & Gas. He is a Chemical Engineer with a PhD in thermodynamics and has extensive experience in advanced process depressurisation and dynamic modelling for Oil & Gas applications.





45 minutes plus Q&A

Vessel blowdown

Depressurisation involves complex, highly dynamic behaviour

Who should attend?

The presentation will be of use to Oil & Gas engineers, especially those with safety or depressurisation experience or remit, dynamic modelling experts and managers with responsibility for asset and plant integrity.

More information

PSE Oil & Gas publishes case studies of applications of advanced process safety analysis. Find out more