Vessel and system blowdown

Transforming and supporting best practice

In the safe design of blowdown systems, an essential design step is to ensure that temperatures resulting from auto-refrigeration during depressurization do not lead to a risk of brittle fracture in both the process equipment and flare system.

Quantitative analysis of the rapid depressurization (“blowdown”) of high-pressure vessels and process piping is an essential element for the design and safety analysis of Oil & Gas facilities and other high-pressure installations.

Process blowdown usually determines the minimum design temperature and thus the material of construction (e.g. carbon steel, low temperature carbon steel or stainless steel) for each part of the facility and so can have a very significant impact on capital cost expenditure. Equally, if wrongly specified, the safety of the facility is at risk.

However, conventional analysis approaches (lumped volume, equilibrium calculations) are increasingly recognised as insufficient as they are neither conservative nor do they provide the correct information for an economic design.

PSE’s approach

PSE Oil & Gas is recognised as being the world leading authority for accurate depressurization system analysis. Our approach is based on:

1. Rigorous non-equilibrium modelling to accurately represent the thermodynamic behaviour of fluids within the depressuring system – using our unique gFLARE technology
2. The use of a distributed ‘flowsheet’ process model that represents the spatial distribution of volumes in the blowdown segment, rather than the conventional practice of representing (‘lumping’) the entire segment as a ‘vessel’.

PSE provides comprehensive services for vessel and system blowdown analysis and related design.

Apply dynamic modelling to your depressurization analysis

The use of a rigorous model-based safety approach based on our gFLARE technology and coupled process and flare network models can result not only in improved process safety but also an improvement in operations and a considerable reduction in CAPEX. Read our case studies to find out how Oil & Gas companies are saving billions.