Improve evaluation of brittle-fracture resistance for vessels
This article discusses a new approach and spreadsheet tool for engineers that can be used to provide operating pressure limits as a function of vessel-metal temperatures.
Process vessels such as towers, drums and heat exchangers can be exposed to low temperatures as part of normal operating conditions or due to a process upset. Carbon and low-alloy steels typically used in process vessels undergo a transition from ductile to brittle behavior as temperature is reduced and are at increased risk of brittle fracture at low temperature. To reduce this risk, the American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code contains requirements for vessels and vessel components with respect to low-temperature operation.1 While these rules are applicable to new construction, API 579-1/ASME FFS-1 Fitness-For-Service uses the rules as the basis to evaluate brittle fracture resistance for existing vessels.2 This article discusses an approach and spreadsheet tool that can be used to provide operating pressure limits as a function of vessel-metal temperatures. These limits can be used as part of a process hazard analysis (PHA) to set operating pressure guidelines for process vessels identified with the potential for low-temperature excursions from auto-refrigeration of light, low-temperature boiling point, liquid hydrocarbons.
To continue reading please, log in to hydrocarbonprocessing.com.
Subscribe now for premium access and unlimited access to the site, including archived articles and the process handbooks. Start a free trial to gain access to articles from the current issue of Hydrocarbon Processing.
Already have an account?
Subscribe today and gain unlimited and immediate access to the site. Plus, you'll receive the next 12 issues of the magazine in your choice of print or digital format. Start your subscription today.
Start a free trial and gain immediate access to the current issue of the magazine plus additional, select content.
30 Day Trial