File:PVE-3854, Last Updated: March 25/11, By: LB

“The Pressure News” published by ABSA has a write up on registering miniature pressure vessels for use in Alberta (Volume 13, Issue 22, June 2008, Page 4). Alberta no longer allows vessels small enough to be classified as fittings to be registered if they are not designed and built in accordance with ASME VIII-1. Under some circumstances the shop inspection will also have to be done by an Authorized Inspector. Each jurisdiction sets the rules for the products under their control. ABSA has set a rule for small vessels in Alberta and put it in writing. Conform and your products can be used.

This is an age old trade-off. What level of restriction do we place on free trade to achieve our safety standards? Do we allow a wide range of products into Canada, and accept the standards that they are built under, or do we restrict ourselves to using a smaller selection of products that meet our local standards? Alberta is the only jurisdiction to insist on VIII-1 for miniature vessels. We have never had a fitting rejected for this reason anywhere else in Canada, and could register them in Alberta this way until the summer of 2010. Further, it was another jurisdiction that taught us to register miniature vessels with unlisted materials this way.

The primary motivation for not using VIII-1 to register miniature vessels is to allow the use of non-code listed materials. Typically piping codes like ASME B31.3 are used which provide methods of adopting unlisted materials. It is a reality that many miniature vessels are made around the world out of non ASME listed materials. This is often done for pulsation dampers as shown in the picture.

See also the burst testing problems page for another issue that treating fittings as small vessels raises.

This is a major change for Alberta, and the rest of Canada if any other provinces go along. Some fittings can be registered across Canada except Alberta. The manufacturer has a choice to make, redesign the product to get access to the Alberta market, or accept registration for the rest of Canada without the re-design. Alternately, two products can be used – a custom product for Alberta and the standard part for the rest of Canada, registered under separate CRN#s.

Update Oct 2011: As of this year ABSA is still occasionally advising some manufacturers to use B31.3 to design miniature vessels for use in Alberta for limited applications. We suggest contacting ABSA to get permission in writing before attempting to use B31.3 on your miniature vessel destined for Alberta.