CRN User’s Survival Guide – Introduction to this Blog

At times I feel obliged to apologize to customers for how difficult Canada’s CRN registration system has become. The emotions can run high when someone has been going up against our poorly documented and constantly shifting regulatory barriers. It is no longer possible for a person with prior pressure vessel design experience but no Canadian registration experience to expect an easy navigation of our system. CRNs are harder to get now than ever before, the waiting time is longer, the costs higher and the need for specialized knowledge has never been greater.

The original goal of this guide was to provide a set of rules to use for CRN submissions in Canada. By documenting accepted methods, we and our customers could work towards the goal of getting easier, faster and less expensive CRN approvals. Along the way it became apparent that single methods for use Canada wide, or even within one province were impossible. Each province is different, and within provinces often individual reviewers have contradictory requirements. All this guide can do is list methods that usually work.

The CRN system is currently splitting in two directions in Canada. Some provinces are finding little value in the system and are looking for easier ways to get safe products in use in Canada. These provinces are accepting the internationally recognized National Board system as an alternative for vessel registration or reducing the scope of fitting requiring registration. Other provinces are currently making the review process more difficult, expensive and varied between provinces. A few are currently debating which direction to follow.

Approximately once a week we encounter new requirements for registration in Canada. It is not possible to track all of these requirements, and this blog would be far too long to be useful. Further, some issues are too sensitive to write about here. If you have anything to share on these topics you can contact me at [email protected] or 519-880-9808 x223.

Wishing you the best of fortune with your Canadian registration challenges.

Laurence Brundrett, Chairman, Pressure Vessel Engineering Ltd.


Registration of Cold Stretched Vessels

Cold stretching has been in use for more than 30 years, but not under ASME code rules until 2008. Cold stretching (or cold working) increases the yield limit of a stainless steel material by work hardening it after all forming and welded steps are complete. The resulting permanent plastic deformation increases the diameter up to 7% and the volume by 14%.



ABSA Survey Process Improvements

We have noted some improvements in the registration process at ABSA in the last 9 months. ABSA has posted policy changes making these improvements possible. Changes in personnel have also been important.



Updated Yet Again – A New Hope

In spite of the ever increasing rules and mountains of paperwork required to register vessels and fittings in Canada, five provinces have been working on alternatives to make the CRN system work better in their provinces.



Updated: National Board Vessels in Saskatchewan

The evolution with Saskatchewan’s experiments in registering new and used vessels only by National Board report.



Design Code used in Alterations

When registering a vessel alteration, you must use the correct section, edition and addenda of the ASME Code.



Nozzle-Pro and CRNs

Although Nozzle-Pro is a very good design tool for the use of designing pressure vessel nozzles and beyond, it does not follow one of the five finite element analysis standards recently required in various Canadian jurisdictions.



Finite Element Analysis – Evolving Acceptance

FEA is now being accepted for not just the proof of cycle life but ALSO proof of structural integrity in both vessels and fittings. The primary catalyst is the change in a number of personnel at ABSA.



Past and Present CRNs

Issues with how the CRN process changes with time, and variation between reviewers.



Maximum Allowable Working Pressure

For Alberta and Saskatchewan, the pressure used in the calculations must be equal to or greater than the MAWP to be marked on the vessel nameplate and manufacturer’s data report.



Registration of Fittings – Changes Since 2005

Proof of burst tests and/or calculations along with detailed product drawings are now required to register fittings – the same requirements as for pressure vessels.



Registration of Plastic Fittings

Plastic pipe that needs to be registered can be calculated to code rules found in B31.1 or B31.3. But a plastic pipe needs plastic fittings – how can they be registered? Plastic fittings are among the most difficult to get registered under the CRN system.



Registering Steam Heated Molds

Steam heated platens and steam heated cavity molds need CRNs in Ontario. Tire molds with steam cavities are registered in Quebec.



Moving or Changing Your Company Name?

If your company changes name or address, do you need to update the registration of your fittings? Yes.



Update CRN for Flange Welds

ASME changed the amount of weld required on a standard B16.5 slip on flanges with the 2009 VIII-1 code update. Slip on and socket weld flanges need larger welds on the outside.



ABSA – Impact Test Information on the Drawing

ABSA requires impact test information to be put on fabrication drawings whenever impact testing is a requirement of the design.



Will I Need to Renew My CRN?

CRNs for fittings expire after 10 years. If the registration is not renewed, no new pressure vessel or piping designs can be registered that use it, however end users keep using the same fittings and ordering spare parts and replacements for existing systems, even though the CRN is no longer valid.



Using Fittings in Vessels and Piping

Under the B51 program fittings need to be registered before they can be used on pressure devices. However, fittings on pressure vessels are exempted from requiring registration by B51. In contrast fittings on piping systems must be registered.



Registering B16.9 Fittings

The user of a B16.9 fitting calculates its pressure rating as an equivalent piece of straight pipe. The manufacturer of the fitting has to provide proof that the fitting is the same strength as that straight pipe. ASME Standard B16.9 does not specify wall thicknesses leaving it up to the manufacturer to design.



We Don’t (Usually) Register Actuators

The actuator on a valve is not part of the piping system for the fluid that the valve is regulating. It is part of the instrumentation piping system. Each province has its own piping rules, but most do not require registration of small diameter air piping systems.



Code Updates

In Canada we do not allow the words “latest code and addenda” on pressure vessel drawings when they are being registered. When the vessel is submitted for CRN registration, the drawing states an actual year and addenda.



Code Cases and Interpretations in Alberta

Alberta does not automatically accept either ASME code cases or Interpretations. Interpretations and code cases are not part of the code, and are not automatically adopted for use in Alberta.



Miniature Vessels in Alberta

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.



Possible Crazy Future CRN Directions

We have had 2 jobs where fittings that carried current CRNs were refused by two jurisdictions because the Code of construction of the piping system did not match the code used to calculate the fittings.