What is a pressure vessel?

Alberta Regulation 49/2006 defines it as “a vessel used for containing, storing, distributing, processing or otherwise handling an expansible fluid under pressure.”  Other legislation and code define it in similar ways.  CSA B51 defines it as “a closed vessel for containing, storing, distributing, transferring, distilling, processing, or otherwise handling a gas, vapour, or liquid.”  In Canada, pressure vessels must be designed in accordance with the ASME Boiler and Pressure Vessel Code.  For non-nuclear equipment, the ASME Rules for the Construction of Pressure Vessels must be met in their entirety.  For all pressure vessels registered in Canada, in the absence of a Variance issued by the jurisdictional regulatory authority, either ASME Section VIII-1, Section VIII-2, or VIII-3 must be met.  Unless explicitly permitted by regulators, mixing code requirements into a single design is not permitted.