Here are some of the most common CRN related questions we get:

Scope and Registration

What gets registered? Both Canada and the United States use the ASME Section VIII-1 code for pressure vessel construction but Canada has a CSA B51 standard that provides a more restrictive definition of what a PRESSURE VESSEL is. Canada also registers FITTINGS – items that in other countries would be considered too small to need registering. Likewise we also register many PIPING SYSTEMS in Canada. All vessels, fittings and piping systems need to be built under appropriate quality control programs.

Who Does the Registration? Each province does its own registration and provides a CRN number which is put on the vessel nameplate. The Atlantic Canada provinces and the northern territories have joined together to use one registration organization, ACI Central. We have 13 provinces and territories, but to register across all of Canada, you must register with 7 Organizations or Jurisdictions.

When Should I Apply for a CRN? The CRN should be applied for before construction begins. To quote B51 “Acceptance and registration shall be obtained before construction is commenced.” For a manufacturer who has a finished vessel, and has been told on the shipping date that the vessel is bound for Canada, this can be a problem. In reality, this requirement varies by jurisdiction, for example the Ontario vessel act offers this alternative: “4.(2) A person who submits a design submission for registration may commence construction of the boiler, pressure vessel, fitting or piping before the submission is registered if the person assumes all risks related to the construction, whether for an installation or alteration.” The more time you allow for the registration the better.

What happens if I don’t apply for a CRN? There are a large number of fittings, piping systems and pressure vessels in use in Canada that require CRNs but were never registered. These products are often uncovered during authorized inspector visits or insurance audits. If a product is discovered while it is in use, then someone has to go through the effort to get it registered at that point. If it cannot be registered then it must be replaced. If it is a safety concern then it must be shutoff until registered or replaced.

I manufacture a fitting that will have my customer’s name on it, not mine. How do I register it? The logos that will be affixed to the product need to be indicated on the statutory declaration. Multiple logos can be registered. If the logos will not fit on the box on the statutory declaration page, put them on an additional page.

Do I need a CRN for a pump? No.

Do I need a CRN for an air compressor? No – but volume bottles between compressor stages and air receiver cylinders need CRNs.

Do I need a CRN for hydraulic components? No – except in circumstances of high operating temperatures. This varies by province.

Do I need a CRN for pneumatic cylinders? No.

Do I need a CRN for bolting or gaskets? No. Bolting and/or gasket information may be required by the connection manufacturer to calculation their design for CRN registration. For example, M & Y values for gaskets or allowable strengths for bolting material.


How long can I manufacture Pressure Vessels to my CRN? The CRN affixed to a vessel is valid for the life of the vessel. For a manufacturer, the CRN can be used until the code changes enough to require the design to be changed, or until design changes are desired.

How long can I manufacture Fittings to my CRN? The CRN for a fitting is valid for 10 years. After that time, the design must be re-registered. For a fitting registered across Canada, all the CRNs expire once the first CRN expires. The expiry date is written on the documentation you get back from your jurisdictions. Fittings in use remain in use even if the fitting CRN expires – identical parts are required for maintenance and repair. If different parts are used then the registration needs updating.

Code Revisions

Do I need to update my pressure vessel calculations with each code revision? Manufacturers have to re-run or review the calculations with each new code release to confirm that the design is still valid. The authorized inspector confirms that the calculations are current or reviewed. This is also how it is done for National Board fabrication.

Do I need to update my fitting calculations with each code revision? Calculations are not normally updated until it is time to re-register the design.

Design Changes

I need to modify a registered vessel. Do I need to re-register it? If the calculations do not need to be updated then the answer is probably no – example, addition of a nozzle identical to one already on the vessel that is not too close to another nozzle – then you will probably not need to re-register it. You must contact your local authorized inspector. Note: work must be performed by a company with a valid QC certificate like an ASME “R” stamp.

Can I change the operating conditions on my vessel without re-registering it? Maybe – if the calculation set does not need to be re-run because of the change, then you might not need to re-register it. Call your jurisdiction.


Does my fitting have to be made of code listed materials? Sometimes – see Unlisted Materials

Can I make my fitting from plastic? Yes – see Registration of Plastic Fittings


Is my quality control system acceptable?

Pressure Vessels and Boilers: ASME U stamps are required for pressure vessels signed off by National Board Inspectors. See TSSA’s list of acceptable inspection agencies.

Piping: requirements vary by province, see the QC section on the Piping – Do I Need a Registration Page?

Fittings: two things must be met :

1) the requirements of B51 Annex F “Quality control program for manufacturers of fittings” must be met, and

2) the program must be 3rd party audited (although this is not a requirement of CSA-B51, this is mandatory). Various 3rd party audited programs can be acceptable ranging from ISO, TUV, Mil Spec, ASME LLoyds, ABS, Det Veritas and provincial B51 programs. The party doing the auditing must be acceptable to the reviewer.

See TSSA document Guidelines for the Registration of Non-nuclear Fittings in the Province of Ontario for further information.  Usually a QC program is accepted based on the scope as written on the certificate without review of the actual program. Sometimes the scope as declared on the certificate is not clear or acceptable leading to a review of the actual program. For example many TSSA B51 piping programs only cover the scope of manufacturing piping systems and can not be used for the manufacture of fittings. Remember that the program only has to cover those items of the B51 Annex F that actually apply to the manufacture of the fitting being registered. For example it is not required to have a program cover welding if the fitting is made only by machining. From B51-14 “The program that the manufacturer uses shall be suited to its circumstances and reflect the complexity of the products produced.”

Can I have more than one manufacturer build fittings for me under 1 CRN? Each fabricator would need to declare their own statutory declarations and provide proof of a suitable QC program. If the jurisdictions can register them together they will, otherwise separate numbers will be issued. This is most likely to work if each fabricator was a different branch of the same company.

Can I have more than one manufacturer build vessels for me under 1 CRN? Yes, all provinces except Saskatchewan allow this. The registration covers the design and assigns it to an owner. The authorized inspector will determine that an adequate QC program and suitable quality control procedures will be followed during the construction. Note that this assumes that all manufacturers have a legal right to build the vessel granted by the owner of the design. See Move or Name Change for more information.

Do I need to label the CRN number on my vessel? Yes – stamp the CRN number on the code nameplate. On my fitting? No, but the manufacturers logo (as shown on the statutory declaration form) must be visible.

Can I build more than one piping system from my piping registration? No – piping systems are registered to an installed address. Unless the installed address remains the same, then each identical copy would need re-registering. Update: Alberta and Ontario have methods of registering mobile piping systems.

Do I need to hydrostatically test my fitting? Hydrostatic or pneumatic test requirements for a fitting depend on the standard that the fitting is designed to:

  • B31.3 piping – “Prior to initial operation and after completion of the applicable examinations required by para. 341, each piping system shall be tested to ensure leak tightness.” (345.1)
  • B16.5 flanges – “Flanges are not required to be pressure tested” (8.1) however, if the item is a flanged fitting, then “each flanged fitting shall be given a shell pressure test” (8.2.1)
  • B16.9 fittings – “Hydrostatic testing of wrought fittings is not required by this standard.” (10)
  • B16.34 valves – “Each valve shall be given a shell test…” (7.1)
  • VIII-1 vessels – “A hydrostatic test shall be conducted on all vessels…” (UG-99(a)).

Moving Equipment

I have a used vessel that was registered in another province. Do I need to re-register it to move it to my province? Yes – you need to submit the original calculations and drawings or re-create calculations and drawings if the originals cannot be found. Requirements vary, but most commonly the calculations need to be re-run using original year of construction stress allowables, but using the latest code rules. A photograph of the nameplate and the manufacturer’s data report are required. Used vessels usually need inspection like ultrasonic testing to prove that the vessel is still adequate.

I have a new vessel from another country. Can I get it registered in Canada? Maybe – are the calculations and drawings available? Is the code of construction acceptable? It is usually not worth the effort if non-ASME codes and materials are used.

I am importing a machine from another country that has a piping system that needs registering. Can I do this or do I need to scrap and replace the piping system? The piping system will need to meet all the requirements of a Canadian registered piping system – acceptable quality control program, acceptable materials, CRNs on all the fittings, calculation set, a drawing with identified code materials. We have been involved in imported machines with piping systems not built to Canadian standards but requiring registration. The process can be very long and expensive (think more than 1 year). It is often easier to start from scratch.