CSA B51 Issues and CRN Registration
September 2, 2025
Whether it is a fitting, pressure vessel, boiler, or piping system that you want to get CRN registration for, Cammar Corporation can help with the design and evaluation so it complies with the governing adopted codes, standards, and regulations. In other words, it needs to meet CRN requirements.
Unless a pressure equipment design is exempt from CRN legislation requirements, it needs to be properly registered with a CRN (Canadian Registration Number) before it can be legally operated. And to get it registered, it needs to comply with the related regulations and meet CRN requirements. Cammar Corportation can help you do this.
Though you can apply to get a CRN number by documenting your CRN design and submitting the appropriate application forms to the regulator in the province or territory where the equipment will be used, regulators can simply reject your CRN design registration application if they are not satisfied that the design meets the requirements of the jurisdictional regulations, adopted codes, and referenced standards.
And, … though regulators must tell you why a design doesn’t meet their requirements, they cannot tell you how to fix a deficient CRN design, since that would put them in a conflicted position. Afterall, they can’t properly accept a CRN design that incorporates their own advice. Though regulators control the CRN registration process, they are not supposed to be, and cannot be, owners.
Each province and territory has rules in its jurisdiction, which must be met. If some jurisdictions have tougher requirements than others, it’s thereby best to apply to the toughest jurisdiction first. For more about how and why to get a CRN, read this.
Alternatively, CAMMAR can assist you directly pursuant to getting a CRN. registration.
If your equipment requires a Canadian Registration Number, you must apply for the CRN before the pressure equipment can be installed and used in Canada. In fact, it is wise to complete your CRN registration before the pressure equipment is in the final stages of design (i.e. before the equipment is built). This will ensure that you follow CSA B51 and other regulations without issue.
In any case, to avoid unnecessary complications, make sure that your CRN registration is completed before any assembled equipment leaves the producer. If the equipment will not be assembled until after it leaves the manufacturer (e.g. the equipment must be assembled in the field), be sure the design has a Canadian Registration Number.
Will your pressure equipment operate at 15 psig or higher? If so, you will likely need a CRN number and, sometimes, even though contained pressures are less than 15 psig, exemptions do not apply. In most cases, pressure equipment in Canada requires a Canadian Registration Number (CRN). That is, unless CRN exemptions apply to your equipment.
CRN exemptions vary from province to province. Therefore, you will need to check the codes and regulations specific to the province or territory in which your pressure equipment is to be used.
If you need a CRN number for your equipment, it must be obtained before the pressure equipment is pressurized.
If you require assistance in determining whether your equipment needs a CRN number, CAMMAR Corporation can help.
Pressure equipment, including pressure vessels, boilers, piping and fittings, used in Canada requires a CRN registration. Equipment must be registered with a CRN before it is used.
In general, if pressure equipment operates at a pressure greater than 15 PSIG it will likely require a CRN registration. In fact, unless a particular exemption applies to the equipment, a Canadian Registration Number is needed.
Keep in mind, provincial and territorial governments have the authority to govern equipment safety in their region. Therefore, CRN registration requirements vary by province and territory. As a result, CRN exemptions are set out by provincial and territorial governments.
It’s the law, in Canada.
Canadian Registration Numbers (CRN numbers) identify unique pressure equipment design concepts for use in Canada, and must meet requirements, in accordance with Canadian statutes and regulations. Canadian law references CSA B51.
Each design concept has a unique CRN number. One Canadian Registration Number can represent millions of individual items, each with a different serial number, that all conform to the CRN design.
Though each provincial jurisdiction has responsibility for the safety of pressure equipment within its borders, Canadian provincial regulatory authorities have cooperated to help ensure CRN numbers are tracked nationwide, and identifiable across provincial boundaries. CRN numbers are required to be stamped on equipment or, in the case of very small fittings, trackable with other identification markings.
CSA B51, the Canadian “Boiler, Pressure Vessel, and Pressure Piping Code”, describes the required rules of CRN use in detail. Part 1, Clause 4 specifies that pressure fittings, pressure vessels, and boilers are assigned CRN numbers with the acceptance of regulatory authorities in provinces where the equipment is to be used.
Vessel and boiler CRN numbers never start with a “0”. Fitting CRN numbers always do.
All CRN numbers have a decimal point that follows the prefix assigned by the regulatory authority.
For fittings, the letter following the “0” in the prefix corresponds to CSA B51 Table 1, and is used by regulatory authorities at their discretion to categorize the fitting according to type:
Subsequent characters in the prefix that precede the decimal, are sequentially assigned by the regulatory authority. For some fitting categories, five digits follow the letter noted above that precede the decimal. For vessels, an alphanumeric (unless the registration is really old) and four digital characters precede the decimal. Following the decimal, the geographical region in which the design was first registered (the originating jurisdiction) is identified with a character listed in Clause 4.3.2.:
1 British Columbia
2 Alberta
3 Saskatchewan
4 Manitoba
5 Ontario
6 Quebec
7 New Brunswick
8 Nova Scotia
9 Prince Edward Island
O Newfoundland
Y Yukon
The prefix, decimal, and character after the decimal identifies a unique design.
To indicate all of Canada, the letter “C” is subsequently used. To indicate all regions in Canada which require registration, the “CL” is used.
Subsequent digits identify other regions in which the design has been registered, in no particular order.
Here are some examples of CRN numbers:
Fitting CRN registrations expire 10 years after the originating registration, and can be renewed before expiry. For example, if 0A.12345.132 was first registered in British Columbia on Jan 31, 2018, and then on in Alberta on March 23, 2019 and Saskatchewan on Aug 19, 2024, then the registration for all three jurisdictions will expire on Jan31, 2028 unless it is renewed in British Columbia before then. Renewal would need to occur in the originating jurisdiction (British Columbia) first and prior to February 1, 2028/ Other jurisidctions can renew the CRN after British Columbia, and not before.
Vessel CRN registations never need renewal.
If the code or regulations become more stringent after registration, then those that have care and control of the design and / or related equipment need to ensure that the registration is revised to meet the new requirements in accordance with regulatory requirements.
Give Cammar Corporation a call to discuss any CRN requirement questions that you might have!
Per ASME Section VIII-1 Appendix 3, MAWP (maximum allowable working pressure) is “the maximum gage pressure permissible at the top of a completed vessel in its normal operating position at the designated coincident temperature for that pressure. This pressure is the least of the values for the internal or external pressure to be determined by the rules of Division 1 for any of the pressure boundary parts, including static head thereon, using nominal thicknesses exclusive of allowances for corrosion and considering effects of any combination of loadings listed in the code that are likely to occur at the designated coincident temperature.“
Per ASME Section VIII-1 Appendix 3, design pressure is “the pressure used in the design of a vessel component together with the coincident design metal temperature, for the purpose of determining the minimum permissible thickness or physical characteristics of the different ones of the vessel. When applicable, the static head shall be added to the design pressure to determine the thickness of any specific zone of the vessel.”
A generic CRN design describes variable dimensions, materials, and feature locations of pressure equipment. For example, a generic vessel CRN design can generally describe a variable shell length, all possible nozzle locations and sizes, together with proximities of nozzle groups etc.* For vessels, generic designs cannot vary the head shape, shell diameter, maximum pressure, maximum temperature, or minimum temperature. For generic fittings, many options are allowed, generally enabling you to register a whole series of fittings with one generic drawing specifying a range of dimensions, materials, and even design pressures.*
*Each situation is somewhat unique and requires careful consideration. Other restrictions may apply subject to regulator acceptance.
Alberta Regulation 49/2006 defines it as “a vessel in which steam or other vapour may be generated under pressure or in which a liquid may be put under pressure by the direct application of a heat source.” Other legislation and code define it in similar ways. CSA B51 Boiler, Pressure Vessel and Pressure Piping Code, defines it as “as a vessel under the Act”. By ‘Act’, CSA B51 refers to the governing statute in each provincial or territorial jurisdiction. For all boilers registered with a CRN in Canada, in the absence of a Variance issued by the jurisdictional regulatory authority, the requirements of ASME Section I must be met in its entirety.
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.
CRN stands for Canadian Registration Number. It is assigned to pressure equipment in Canada by provincial regulatory jurisdictions. Unless exempt from CRN registration , all pressure equipment must be registered with a CRN before use in Canada. It is not the same as certification markings such as CSA, UL, FM, Intertek etc.
B31.3 is the ASME (American Society of Mechanical Engineers) code for process piping. This code outlines the requirements for materials, design, fabrication, assembly and erection of piping systems. The proper examination, inspection, and testing of piping is also covered by B31.3.
The piping systems governed by this code include those that contain fluids. Typically, these piping systems are found in:
ASME B31.3 is used in conjunction with ASME B31.1, and other B31 codes, to ensure the safety of piping systems. Adhering to these codes also helps the system to meet government regulations and receive a CRN.
B31.1 is the ASME code for power piping. B31.1 was developed by the American Society of Mechanical Engineers (ASME) and is used worldwide. This code outlines proper methods for the installation, inspection, and maintenance of power piping systems. ASME B31.1 also provides requirements for the operation, design, materials, fabrication, erection, and testing of piping systems.
The piping systems governed by this code are commonly found in:
B31.1, along with B31.3 and other ASME B31 codes, is intended to ensure the safety of piping systems. These codes are essential for:
The biggest difference between ASME B31.1 and B31.3 is their requirements. In fact, although these codes are often used in conjunction, they vary significantly in their CRN registration requirements.
Some of the most common differences between ASME B31.1 and B31.3 include scope, allowable strengths, unlisted material specification, non-service hydro pressure testing, pneumatic pressure testing, service testing, alternatives to pressure testing, radiography and ultrasonic testing, minimum design metal temperature (MDMT) and impact testing requirements.
Although these codes differ extensively, equipment that meets ASME B31.1 and B31.3 requirements is possible to design and develop. Products that meet both standards can also receive CRN registration. The benefit of designing and registering equipment that meets all requirements is that it can be sold to a larger number of buyers.
The difference between ASME vs API is that ASME standards hold more weight than API standards. That is, adherence to ASME standards is required for CRN registration. On the other hand, API specifications are only recommended practices.
The ASME, or the American Society of Mechanical Engineers, provides codes that govern the safety of mechanical equipment. These codes are meant to provide overarching specifications for mechanical engineering applications.
The API, or the American Petroleum Institute, on the other hand, produces recommended guidelines. In most cases, these standards are simply intended to encourage safety. Most commonly, these guidelines are directed at offshore structures that are used by oil and gas companies.
The difference between power piping vs process piping has to do with the type and quality of matter that each system transports.
Power piping refers to piping systems that are used to distribute high-pressure steam, high temperature and high-pressure water, compressed air etc. Typically these piping systems will be found in buildings that generate electric power, industrial plants, as well as heating and cooling systems.
On the other hand, process piping is used to distribute liquids, gasses and chemicals. Commonly, process piping is installed in petroleum refineries, chemical plants, pharmaceutical plants, textile plants, paper plants, semiconductor plants, and cryogenic plants, as well as other processing plants.
Regarding ASME codes, ASME B31.1 governs the design, development, installation, use and testing of power piping systems, while ASME B31.3 is intended to be applied to process piping systems. CRN training will further address these specifications.
Is there CRN training available from Cammar Corp?
Cammar Corporation can provide customized training for your staff, in relation to CRN registration and topics listed here, or others. We have the experience to prepare and deliver it.
Training would typically occur over one or two days for select topics, to audiences of five or more persons that belong to your organization. There’s lots of information to consider and understand:
For more details on training please our Canadian Registration Number (CRN) Training page.
It’s the law, in Canada.
Canadian Registration Numbers (CRN numbers) identify unique pressure equipment design concepts for use in Canada, and must meet requirements, in accordance with Canadian statutes and regulations. Canadian law references CSA B51.
Each design concept has a unique CRN number. One Canadian Registration Number can represent millions of individual items, each with a different serial number, that all conform to the CRN design.
Though each provincial jurisdiction has responsibility for the safety of pressure equipment within its borders, Canadian provincial regulatory authorities have cooperated to help ensure CRN numbers are tracked nationwide, and identifiable across provincial boundaries. CRN numbers are required to be stamped on equipment or, in the case of very small fittings, trackable with other identification markings.
CSA B51, the Canadian “Boiler, Pressure Vessel, and Pressure Piping Code”, describes the required rules of CRN use in detail. Part 1, Clause 4 specifies that pressure fittings, pressure vessels, and boilers are assigned CRN numbers with the acceptance of regulatory authorities in provinces where the equipment is to be used.
Vessel and boiler CRN numbers never start with a “0”. Fitting CRN numbers always do.
All CRN numbers have a decimal point that follows the prefix assigned by the regulatory authority.
For fittings, the letter following the “0” in the prefix corresponds to CSA B51 Table 1, and is used by regulatory authorities at their discretion to categorize the fitting according to type:
Subsequent characters in the prefix that precede the decimal, are sequentially assigned by the regulatory authority. For some fitting categories, five digits follow the letter noted above that precede the decimal. For vessels, an alphanumeric (unless the registration is really old) and four digital characters precede the decimal. Following the decimal, the geographical region in which the design was first registered (the originating jurisdiction) is identified with a character listed in Clause 4.3.2.:
1 British Columbia
2 Alberta
3 Saskatchewan
4 Manitoba
5 Ontario
6 Quebec
7 New Brunswick
8 Nova Scotia
9 Prince Edward Island
O Newfoundland
Y Yukon
The prefix, decimal, and character after the decimal identifies a unique design.
To indicate all of Canada, the letter “C” is subsequently used. To indicate all regions in Canada which require registration, the “CL” is used.
Subsequent digits identify other regions in which the design has been registered, in no particular order.
Here are some examples of CRN numbers:
Fitting CRN registrations expire 10 years after the originating registration, and can be renewed before expiry. For example, if 0A.12345.132 was first registered in British Columbia on Jan 31, 2018, and then on in Alberta on March 23, 2019 and Saskatchewan on Aug 19, 2024, then the registration for all three jurisdictions will expire on Jan31, 2028 unless it is renewed in British Columbia before then. Renewal would need to occur in the originating jurisdiction (British Columbia) first and prior to February 1, 2028/ Other jurisidctions can renew the CRN after British Columbia, and not before.
Vessel CRN registations never need renewal.
If the code or regulations become more stringent after registration, then those that have care and control of the design and / or related equipment need to ensure that the registration is revised to meet the new requirements in accordance with regulatory requirements.
Give Cammar Corporation a call to discuss any CRN requirement questions that you might have!
So what is a CRN? CRN stands for Canadian Registration Number, as defined in CSA B51.
Canadian Registration Numbers (CRN numbers) identify unique pressure equipment designs for use in Canada, and must meet requirements. Each design concept has a unique number. One Canadian Registration Number can represent millions of individual items, each with a different serial number, that all conform to the CRN design.
Canadian provincial regulatory authorities have cooperated to help ensure CRN numbers are tracked nationwide, and identifiable across provincial boundaries. CRN numbers are required to be stamped on equipment or, in the case of very small fittings, trackable with other identification markings.
CSA B51, the Canadian “Boiler, Pressure Vessel, and Pressure Piping Code”, describes the required rules of CRN use in detail. Part 1, Clause 4 specifies that pressure fittings, pressure vessels, and boilers are assigned CRN numbers with the acceptance of regulatory authorities in provinces where the equipment is to be used.
Vessel and boiler CRN numbers never start with a “0”. Fitting CRN numbers always do.
All CRN numbers have a decimal point that follows the prefix assigned by the regulatory authority.
For fittings, the letter following the “0” in the prefix corresponds to CSA B51 Table 1, and is used by regulatory authorities at their discretion to categorize the fitting according to type:
A – pipe fittings
B – flanges
C – line valves
D – flexible connections
E – strainers, filters, separators, traps
F – instrumentation
G – over pressure protection devices
H – items not in categories A to G
Subsequent characters in the prefix that precede the decimal, are sequentially assigned by the regulatory authority. For some fitting categories, five digits follow the letter noted above that precede the decimal. For vessels, an alphanumeric (unless the registration is really old) and four digital characters precede the decimal. Following the decimal, the geographical region in which the design was first registered is identified with a character listed in Clause 4.3.2.:
1 British Columbia
2 Alberta
3 Saskatchewan
4 Manitoba
5 Ontario
6 Quebec
7 New Brunswick
8 Nova Scotia
9 Prince Edward Island
0 Newfoundland
Y Yukon
The prefix, decimal, and character after the decimal identifies a unique design.
To indicate all of Canada, the letter “C” is subsequently used. To indicate all regions in Canada which require registration, the “CL” is used.
Subsequent digits identify other regions in which the design has been registered, in no particular order.
Here are some examples of CRN numbers:
1. B1234.256
pressure vessel design initially registered in Alberta, and also registered in Quebec and Ontario
2. B1234.265 same CRN number as noted in 1 above despite reversal of “65”
3. B1234.465 pressure vessel design different from items 1 and 2, and registered first in Manitoba
4. 0B1234.265 flange design registered first in Alberta
5. 0B1234.165 flange design different from that identified in item 4, and registered first in British Columbia
6. 0B1234.2C flange design as noted in item 4, but registered in all Canadian regions
7. 0B1234.2CL flange design as noted in item 4 above, but registered in all Canadian regions except those where registration is not required
Give Cammar Corporation a call to discuss any CRN requirement questions that you might have!
Canadian jurisdictions have enacted laws to protect the public where there is danger. And pressure equipment is potentially extremely dangerous. Even a small air receiver, with an internal pressure of just 230 psig, has the explosive energy of about 1 lb of dynamite.
It’s defined somewhat differently across Canada, but Alberta has some pressure equipment definitions that are good benchmarks to consider. The most common types of pressure equipment are classified as:
• boilers,
• pressure vessels,
• pressure fittings, and
• pressure piping systems.
Though there are some exceptions, 15 psig (101kPag) is frequently the threshold at which the provisions of legislation kick in. But danger exists at lower thresholds too.
Consider ordinary, improperly used oil drums. With a diameter of about 22.5 inches, an oil drum pressurized with air to just 10 psig would exert an internal force in the order of 4000 lbs on it’s flat end. Dangerous indeed.
What is an “expansible fluid”? It means “((i) a vapour or gaseous fluid, or (ii) a liquid under pressure and at a temperature at which the liquid changes to a gas or vapour when the pressure is reduced to atmospheric pressure or when the temperature is increased to ambient temperature.” (AR 49/2006 1(1)(l))
The term “boiler” means “a vessel in which steam or other vapour may be generated under pressure or in which a liquid may be put under pressure by the direct application of a heat source.” (AR 49/2006 1(1)(f)) The term “pressure vessel” means “a vessel used for containing, storing, distributing, processing or otherwise handling an expansible fluid under pressure.” (AR 49/2006 1(1)(cc))
Canadian jurisdictions have enacted laws to protect the public where there is danger. But danger exists at lower thresholds too. The term “fitting” means “a valve, gauge, regulating or controlling device, flange, pipe fitting or any other appurtenance that is attached to, or forms part of, a boiler, pressure vessel, or fired-heater pressure coil, thermal liquid heating system or pressure piping system.” (AR 49/2006 1(1)(n))
The term “pressure piping system” means “pipes, tubes, conduits, fittings, gaskets, bolting and other components that make up a system for the conveyance of an expansible fluid under pressure and may also control the flow of that fluid.” (AR 49/2006 1(1)(aa)) All pressure equipment, not exempted from registration requirements, needs to be registered with a CRN before it can be legally operated in Canada. Why are there CRN requirements?
It’s about public safety. Call Cammar Corporation for more information about the CRN registration process.
Whatever pressure equipment you need a CRN registration for, whether it is a fitting, pressure vessel, boiler, or piping system component, CAMMAR can help with the design and evaluation so it complies with the governing adopted codes, standards, and regulations. In other words, we can help your design meet CRN requirements.
Various types of companies and projects ask for CAMMAR’s CRN assistance, ranging from huge international end users and manufacturers, to relatively local companies. Their needs are the same: quality design is needed so that CRN registration is as solid as possible, and so that owners can be best assured that they are fulfilling their regulated responsibilities. Though regulators accept designs for CRN registration, they do not take any ownership or responsibility for the design; so the owner needs to pay even more attention to design detail than the regulator does.
Whether overseeing a large project that includes multiple pieces of pressure equipment, or the manufacture of a single small fitting, CAMMAR provides detailed expertise and direction as needed, to get the job done properly. CAMMAR Corporation assists clientele by providing comments, oversight, and appropriate insight pursuant to proper CRN registration in accordance with good engineering practice, applicable code, and regulation requirements.
Tailored CRN training sessions can be tailored by CAMMAR to address your specific CRN topics, to help your company meet its needs. We can help you learn how to properly acquire CRN number registration, and to properly evaluate or redesign your pressure equipment.
Remember, unless a pressure equipment design is exempt from legislation requirements, it needs to be properly registered with a CRN (Canadian Registration Number) before it can be legally operated. And to get it registered, it needs to comply with the related regulations and meet CRN requirements. We can help you do this.
Cammar Corporation is the combination of engineering experiences extending back to 1989. It’s Director, Cameron Sterling, MSc, PEng, worked on staff at ABSA, the CRN regulatory authority in Alberta, as a Safety Codes Officer evaluating CRN designs. The company has a solid foundation based on honesty, service, unyielding perseverance of quality and safety, proficient regulatory and technical expertise, thoroughness and practical experience. Cammar is licensed to practise professional engineering in Alberta, Saskatchewan, & Ontario.
