Generic Designs Revisited

The truth is, fewer CRNs are better in many ways.  

With fewer CRNs, it’s easier to keep track of CRN registration numbers, it’s easier to ensure the right CRN registration number is affixed to the right equipment, and it’s easier if the regulators need not be contacted as much.

It’s usually possible to combine several pressure equipment designs of a particular type into one design.  This is what a generic design is all about.

Generic Pressure Vessels and Boiler Components

For example, pressure vessels or boiler vessels and components with different nozzle locations in heads and shell, different nozzle sizes, and different shell lengths can be combined into one design, i.e. a generic design.  For pressure vessels, nozzle spacing tables showing required nozzle spacing distances in accordance with ASME Section VIII-1 paragraphs UG-36, UG 37, UG-39, UG-40, UG-41, UG-42, UW-14, etc., can be included on the drawing and considered as part of a design.  Similarly for boiler vessels and components, nozzle spacings are governed by paragraphs PG-32 etc.  

Only relative locations of nozzles need to be prescribed; specific locations for each nozzle need not be defined.  In this way, a virtually unlimited number of nozzle combinations and locations can thereby be included with a vessel design, as long as they reasonably represent the product line and market demand.  The idea is not to combine all possible nozzles at all possible locations, at all nozzle offset distances, and at all nozzle inclination angles.  A reasonable set of nozzle locations and sizes is acceptable to the regulators.

Generic vessels must have a fixed:

  • design pressure 
  • max design temperature, 
  • minimum design metal temperature (MDMT), 
  • shell diameter, 
  • corrosion allowances for each vessel component, 
  • weld configuration for each nozzle
  • head type
  • head and shell thicknesses, and
  • materials of construction, with reasonable exceptions.

A drain must be located at a location to permit drainage, if required.  And inspection openings, if required, must be located within a diameter’s distance of the heads’ circumferential seams.

Generic Fittings

Fittings designs are regularly combined into one application for CRN registration, as long as the same fitting category is considered.  For example, a catalogue of category A ASME B16.9 pipe fittings can be registered with one application.  Same thing for various different catalogues with sets of drawings: category B flanges, whether ASME B16.5 or custom in accordance with ASME Section VIII-1 Appendix 2; category C valves fittings in accordance with ASME B16.34, or ASME B31.3, etc.; category D expansion joints or hose assemblies; category E filters, separators, or steam traps; category F measurement instruments like gauge glasses, pressure transmitters, flow meters, etc.; or category G pressure relief valves, rupture disks and fusible plugs.  Such CRN registrations cover a wide range of sizes, pressure ratings, temperature ratings, materials of construction, etc.  In general, requirements for generic fittings are less stringent than for pressure vessels.

An exception to the above is for category H fittings, which typically look like little pressure vessels.  For generic CRN registrations involving category H fittings, it is advised to apply the guidelines for generic vessels  noted above. 

Revisions and Additions to Generic CRNs

After registration is obtained and before it expires, a CRN revision can add new design models or variations to the list of equipment already included with a CRN registration.  With a revision to a CRN, the same CRN number can be used for new models or for design variations, further to what was originally anticipated.

ASME B31.3 is different than API 6A. FInd out how with Cameron Sterling from Cammar.

API 6A Is Not The Same as ASME B31

API 6A and ASME B31.3 Chapter IX High Pressure Piping Components are NOT the Same.

As those in the oil and gas industry venture to where ASME codes prevail, you could find out the hard way that API standards do not govern these component designs. Expensive assumptions about API applicability can be made incorrectly, at great cost to budgets and schedules. In Canada, regulators like ABSA in Alberta and the TSSA in Ontario govern pressure equipment use and CRN registration requirements when related safety regulations apply.

For example, API 6A – Specification for Wellhead and Christmas Tree Equipment, is unacceptable as a code of construction for valves or equipment for any ASME B31.3 service in the jurisdiction of CSA B51. Regardless, many high-pressure valve and equipment suppliers often mistakenly use API 6A as their standard and do not realize that its requirements differ markedly from ASME B31.3 Chapter IX.

Here’s a quick list of some significant requirements associated with ASME B31.3 Chapter IX for you to consider:

User Design Specification:

Per paragraph K300, at their option to use Chapter IX as the code of construction, the owner must designate piping as being in ASME B31.3 Chapter IX high-pressure fluid service and must provide the designer with all system operation information necessary to properly design the equipment. In return, the designer must make a written report to the owner that certifies that calculations and the design have been performed in accordance with the code requirements.

Cyclic Analyses:

Cyclic analysis is necessary per paragraph K304.8 unless the owner designates that the piping system will not undergo cyclic loading, that there will be no pressure or temperature cycles throughout the lifetime of the piping system. If the component is listed and conforms to standards listed Table K326.1, fatigue can be analyzed with either ASME Section VIII-2 or ASME Section VIII-3 methodologies.


For pressures that exceed #2500 class, flanges are to be validated through ASME Section VIII-2 Part 4 calculations, per paragraph K304.5.1(b). Regulators will be reluctant to consider proof tests or FEA justifications.

Unlisted Components:

Valves etc. not conforming in any way to ASME B16.34 per K307.1 and other components unlisted in ASME B31.3 Chapter IX per K304.7, must be validated through an ASME Section VIII-3 finite element analysis (FEA) which inherently includes a VIII-3 fatigue analysis, a proof test, or a combination of both these methods. Even with meticulous records and affidavits, it is exceedingly difficult to adequately document successful service to the satisfaction of the regulator and all stakeholders.

Proof Testing:

Proof test pressure is different in ASME Chapter IX than for ASME B31.3 Chapter VI requirements and is a function of yield strength at ambient and at temperature.

Listed Materials and Allowable Strengths:

Refer to Table K-1 of ASME B31.3, not Table A-1 for pressure boundaries. Refer to ASME Section VIII-2 for bolting materials per paragraph K309 and Section VIII-2. Allowable strengths are a function of yield strength alone, per paragraph K302.3.2.

Pressure Boundary Thicknesses:

Cylinder thickness is calculated based on thick cylinder theory per ASME B31.3 Chapter IX paragraph K304.1.2, and differs from the thin-walled theory approach of ASME B31.3 Chapter II.

Impact Testing:

Impact tests are necessary for base metals and welds in accordance with ASME B31.3 Chapter IX Table K323.3.1 requirements, further to material specifications. Exemptions unrelated to specimen size are unavailable. There are no exemptions associated with material thickness.

Valid Canadian Registration Number (CRN) Database and Directory Information

Valid Canadian Registration Number (CRN) Database and Directory Information

To ensure a strong supply chain, industry often needs to locate manufacturers of CRN registered pressure equipment. Pressure piping, vessels, boilers, and thermal liquid heating systems unexempt from CRN registration need components suitable for CRN registration and, though it can be difficult to find legitimate manufacturers, locating them and the registered pressure equipment they make is necessary.

Is there a legitimate directory available to the public and industry, that lists the tens of thousands of CRN numbers that exist? And is there a published list of all legitimate manufacturers in a jurisdiction with acceptable quality control programs?

Yes! There already are legitimate and valid CRN directories on official regulator and registrar websites, that are publicly available to everyone that wants to look for CRN registration records. Only regulators have access to all legitimate CRN registration and manufacturer information, keep it complete and up to date as much as possible, and publish it as they see fit in accordance with their governing regulations. However, significantly incomplete, substantially limited, and unofficial lists are found elsewhere on the internet.

CRN’s are considered confidential information and many manufacturers do not want their CRN information published by others, as commonly evidenced by non-disclosure agreements and requirements for confidentiality.

Given the relatively high concentration of pressure equipment per capita in Alberta, it is worthwhile knowing that the Alberta regulator (ABSA) has allowed access to its CRN Directory here: And though less populated, the maritime provinces’ CRN Directory can be accessed here, with the assistance of the registrar (ACI Central) and permission of the CRN recipients: The ABSA directory is searchable based on particular CRN numbers, while the ACI Central directory is searchable by CRN and / or manufacturer name. ABSA search results provide the manufacturer name, CRN, drawing number, description, and expiry date. The ACI Central site also provides a more detailed description, including notes associated with the registration.

Using these two CRN Directories, manufacturers with pressure equipment registered in Alberta and / or the maritime provinces can be located and, if the equipment is registered in other jurisdictions too, it’s ordinarily noted.

Fitting CRN registration numbers are categorized per Table 1 of CSA B51, according to the following schedule:

Category Type of Fitting
A pipe fittings, such as elbows, tees, couplings, wyes, caps, unions, etc.
B flanges
C Line valves
D expansion joints, flexible assemblies, hose assemblies etc.
E Strainers, filters, and steam traps etc.
F Measurement devices such as pressure gauges, levels, transducers etc.
G Pressure relief devices
H All other pressure retaining components that don’t fall into categories A through G


Unfortunately, wide searches within a fitting category cannot be manually conducted instantaneously. However, formats of CRN numbers as defined in CSA B51 assists with searching the CRN directories for suitable manufacturers. A fitting category letter is included with all fitting CRN numbers, and so specific searches for manufacturers of fitting categories can be made.

For example, if you want to find a piping fitting manufacturer that initially registered their equipment in Alberta, you can successively conduct a manual search using the 0AXXXXX.2 number format until a manufacturer (or all such manufacturers) are found. Similarly, if you want to find a piping fitting manufacturer that first registered their design in Ontario, then you can successively conduct a manual search using the 0AXXXXX.52 format until a manufacturer (or all such manufacturers) are found.

Spending just a minute or so with the ABSA search template, and starting a search at 0A10000.2, revealed the one of thousands of CRN registrations listed there: 0A10032.2. To the best of ABSA’s knowledge, data published on their site is valid, and includes the manufacturer name, registration details, and the expiry dates of all pressure equipment registered in Alberta. A lengthier search, or a lengthier search within a different fitting category, will yield more lengthy lists of CRN numbers and manufacturers!

For the maritime provinces, similar CRN registration searches can also be conducted with manufacturers’ names, and this can shorten the searching process.

The legality of scraping websites with even a simple VBA software routine, to systematically identify and log all fitting CRNs and manufacturers, is questionable since ABSA has claimed copyright on its website contents. Public access to the CRN registration directory information is freely available to anyone that would like to look for it.

A list of qualified manufacturers is also a good place to start looking for registered fittings that might be of interest to you. ABSA publishes a searchable list of all Alberta companies qualified to manufacturer all categories of pressure fittings here: . Manufacturers with an acceptable quality control program can get CRN registration for fittings, provided that the designs meet code and regulation requirements.

CRN Number

Is The CRN Valid and Legit?

“It’s registered they said.  Here’s the proof they said.”

Really. Ok, so what can you believe?

As an end user of pressure equipment (valves, flanges, fittings, instrumentation, vessels, boilers, thermal liquid heaters, etc), you are responsible for its safe operation in accordance with all applicable ASME codes, standards, and jurisdictional regulations.  This means that you need to ensure it is properly registered with a CRN.  CAMMAR Corp can help you do this.

“But wait a minute.  Aren’t the regulators responsible for registering pressure equipment?”  Nope, they aren’t. They just accept it for registration, but before the equipment is used, sold, distributed or even offered for sale, the responsibility for registering it, and ensuring that it is registered properly, rests with those who have care and control over it.  Regulators don’t own it.

“Ok, but I asked the vendor if it was registered and they said it was.  They even provided ‘proof’ of the registration with the CRN number. And that CRN is valid, so it’s registered, right?”

Uh, not necessarily.

For example, suppose your project needs some ASME B16.34 valves with a CRN number.  You ask your vendor for proof of registration, and they provide you a copy of a stamped Statutory Declaration with CRN included.  But what they neglect to tell you is that the acceptance letter provided by the regulator has a condition included, that goes something like this: “Only valves which comply with all aspects of ASME B16.34 in its entirety are part of this registration.”

So, what does that mean?  

It means that the regulator does not always itemize which of the vendor’s valves or items meet the requirements and which do not.  And with the note above, if pressure parts of any valves are made from any materials not listed in ASME B16.34 and supported by mill test reports, then those valves are not registered.  And if the flanges of those valves are improperly reamed or hollowed out, or chambered, too thin, too short, or whatever, and thereby don’t meet ASME B16.5 or B16.47 dimensions in their entirety, the valves are not registered.  Etc.

So, even though there may be a CRN number, the equipment might well not be registered.  Despite what your vendor might tell you!  

And if you were to use such excluded valves or equipment anyways, it would be like you were using unregistered equipment…!  And you don’t want to go there!

Make sure the pressure equipment you want to use is registered properly with CRNs. We, at Cammar Corporation, can help you deal with the complexities of getting a CRN registration. Call Cammar Corporation right away.

Answer Key

Responsibility for CRN Numbers and Safety

In this space, some questions posed by customers and industry are published in case others have similar questions. Anonymity is preserved. Check back for updates and new correspondence.

Dear Cammar,
If a vessel, fitting, boiler design, or some pressure piping not meeting the legislation requirements and/or that is simply not registered with a CRN number is operated, then so what?
IM Concerned

Dear Concerned,

Safety is a big deal to the public, the engineering profession, and the regulator. Breaking the law is not a good idea.

Unless exemptions apply, operation of pressure equipment (vessels, fittings, boilers, pressure piping systems, etc) that does not meet the legislation, or that is without CRN registration, would be against the law.

Though non-exempt pressure equipment certainly needs to be registered before operation, the equipment also needs to meet the minimum requirements of the adopted codes and standards. In all cases, it needs to be safe.

Committing an offense has potential consequences. For example, in Alberta per Section 68 of the Safety Codes Act, those found guilty are subject to a potential fine of $100000 and imprisonment of 6 months for a first offence, and a fine of $500000 and imprisonment of 12 months for a second or subsequent offence.

So… safety, and responsibility for it, is important.

Answer Key

Bleed Ring Design Responsibility Q&A

In this space, some questions posed by customers and industry are published in case others have similar questions. Anonymity is preserved. Check back for updates and new correspondence.

Dear Cammar,
Does ABSA require that bleed rings be registered or not? I don’t see anything in the pressure equipment safety regulation that exempts bleed rings from having CRN number registration.
I look forward to hearing from you.

IM Concerned

Dear Concerned,
Thanks for your email.
ABSA reportedly does not require CRN number registration for bleed rings – in general. See page 5 of for more information. But each circumstance should be considered on its own merits. For example, a pressurized cylinder sealed with o rings between two ASME B16.5 flanges and held together with threaded bars connecting the flanges, is not a bleed ring. The line between a bleed ring and something else can be blurry and open to interpretation.

What is always necessary is a safe design. Instead of your question, a better question would be: can the device with the pressure port included, safely withstand the proposed pressure? ‘Safely’ means within the factor of safety specified by the code of construction as a minimum. Regardless of whether pressure equipment needs a CRN number or not, the design always needs to meet the minimum requirements of available codes and standards, and the design must thereby provide an acceptable safety margin that the designer, vendor, and end user can responsibly attest to.


How much does a CRN Cost?

The biggest CRN cost might surprise you.  Marketing and operation delays end up costing much more than CRN application and regulator costs. Regulators’ bills aren’t the biggest thing. The regulator will charge as little as about $150CAD or much, much more. Poorly prepared applications for CRN registration will be either rejected, or subjected to a very lengthy iterative review, or both.

Responsibility for registration and application quality rests with the applicant.

Well prepared, professional quality CRN applications will often take a regulator about two to three hours to review on average and this equates to regulator fees of about $500CAD or so or less. But they have many, many applications to review and it might well take a few weeks for an application to reach the top of their pile unless extra expediting fees are paid. Costs are legislated, and registrar’s rates are published (see links here), but regulators’ time can be charged on a half hourly rate if an application is very complex or large. Larger or more calculation intense applications, like a heat exchanger or firetube boiler, will take the regulator a little longer to review but if everything is in order, only a slightly larger fee can be expected for all but the most complex or large applications.

Regulators are NOT responsible for your design.

Poorly prepared CRN applications, that consist basically of a pile of unorganized and unreferenced documents, non-compliant designs, catalogues, drawings, etc., used to be entertained by regulators while the applicant provided corrections. But sorting through such an application would take a regulator longer to evaluate and, as a result, refusals are now a real option. Applicants that rely on the regulator to check their application, to perform the applicant’s quality control, i.e. to do the applicant’s work, are more likely to get a shocking surprise – a bill and no registration! Poor quality applications would result in wasted application and evaluation fees, sometimes higher costs, registration applications that are rejected, and poor relationships with regulators.

Worse yet if a design is mistakenly registered by a regulator, then reactively correcting a mistake once discovered or revealed can obviously be colossally more expensive in terms of reputation than what a proper design application preparation would have been in the first place. Responsibility for registration rests with the owner (end user, seller, distributor, manufacturer, designer, applicant etc.), and recalling or replacing a design that is already distributed and in use can be very expensive. Proper review and checking before an application for CRN registration is submitted should be welcomed, not criticized.

Optimize registration costs by minimizing CRN application delays and mistakes.

Before an application for registration is submitted, ensure that your registration application contains the required information, that the information it contains is correct, that it is well organized with interconnected consistent documents, and that the design meets or exceeds all required regulations, code and standard requirements.

Generic CRN Registration Cammar Corporation

Generic CRN Registration

It makes the most sense to include as many options as possible in a generic CRN registration to minimize the frequency of applications. In general, it is up to the applicant how they want to organize their CRN registration applications in accordance with model numbers, equipment use, markets, etc.

To help optimize the registration process, it is important to consider what a generic design is and if it makes sense to use in your circumstance.
When a design includes options or variations, the design is called generic. In other words, a generic design describes a range of options for the equipment. And if the design is described properly, in many circumstances only one CRN is required for a generic fitting or a generic vessel.

Except for category ‘H’ fittings, any number of model numbers and configurations of the same category can often be included in one generic CRN registration. For example, a bunch of control valves, ball valves, globe valves and butterfly valves are all inline valves and could all be included in a single category ‘C’ CRN registration number. Or a bunch of ASME B16.5 and custom ASME Section VIII-1 Appendix 2 flanges could all be included in a single category ‘B’ registration number. Similar considerations apply for pipe fittings (category ‘A’), expansion joints (category ‘D’), strainers, filters, evaporators and steam traps (category ‘E’), instrumentation including measuring devices like pressure gauges, level gauges, sight glasses, levels, and pressure transmitters (category ‘F’), and certified relief valves and fusible plugs (category ‘G’). Generic category ‘H’ fittings can also be registered but requirements are a bit more restrictive and akin to generic vessel registration.

Generic vessel CRN registration requirements are more restrictive. Authorized inspectors need to quickly ascertain whether a vessel design meets registration requirements or not. So, to avoid generic vessel applications where every conceivable option and geometry is proposed for registration under a single CRN number, some guidelines have been put in place by ABSA. In addition to ordinary design requirements, generic vessels are also to have:

  • fixed maximum allowable working pressure (MAWP)
  • fixed maximum allowable temperature
  • fixed minimum design metal temperature
  • fixed corrosion allowance
  • fixed head geometry and thicknesses
  • fixed diameter(s)
  • all relocatable and optional nozzles, together with their potential locations, identified
  • a nozzle spacing chart for relocatable nozzles meeting requirements of ASME Section VIII-1 paragraph UG-36 for pairs and clusters
  • only one nozzle configuration (neck thickness, internal projection, weld size and reinforcement) for each nozzle size, except for ASME Section VIII- paragraph UW-16(f) fittings

To achieve the maximum amount of spacing variations, nozzles normally exempt from reinforcement per ASME Section VIII-1 paragraph UG-36 should instead be reinforced.

Depending on complexity, generic vessel designs might take slightly longer for the regulator to evaluate and register, but if all possible variations of a vessel are included with one CRN number, it is of benefit to the design owner to register a generic design. Even complex generic designs can be described clearly so that registration is not significantly delayed.

Answer Key

CRN Renewal Q&A

In this space, some questions posed by customers and industry are published in case others have similar questions. Anonymity is preserved. Check back for updates and new correspondence.

Dear Cammar,
We have a fitting CRN for some equipment in Alberta and a second Canada wide fitting CRN that originated in Ontario for different models of the same equipment category. If we renew the Canada wide CRN, is it advisable or possible to add the equipment registered in Alberta to the Canada wide CRN that was first registered in Ontario?
I M Interested

Dear Interested,
In general:

  • In general, fittings registered with a CRN in one province can be added to a Canada wide registration that has a different CRN, subject to regulator acceptance. It is arguably easier for manufacturers to have one CRN for all of Canada to avoid a very problematic situation where the CRN and province to where the equipment is shipped or stocked do not match. Our advice therefore continues to be that when equipment is to be used in all provinces, Canada wide registration should be sought whenever possible to best avoid any problems associated with not doing so.
  • Some categories of fitting registrations like piping (Category A), flanges (category B), or inline valves (Category C), etc. can include any combination, or number of models if requested by the manufacturer, but at the discretion of the regulators. Category H fittings are less accommodating.
  • Regulators will try to avoid duplicate CRN numbers in their province if they become aware of overlap, to help ensure consistency and avoid confusion. If an overlap is noticed, the applicant might be asked to not renew or merge one CRN in favour of the overlapping Canada wide one.
  • For example, if Ontario adds fittings registered in Alberta to 0******.5**, then if/when Alberta agrees to the addition and if they notice, Alberta might well ask that fittings already registered in Alberta be extracted from 0*****.2 or if the fittings already registered in Alberta comprise all the designs in 0*****.2, they might ask that 0*****.2 be merged with the Ontario based registration number. (Actual CRNs are masked to preserve anonymity)
  • If a fitting CRN has a ‘2’ after the decimal, then additions to the existing CRN must be initiated in Alberta. Additions must be initiated in the province where the CRN was first issued, else the amended CRN would be invalid since the originating province would not know about the addition and a new CRN would need to be issued by an alternate province if it accepts the application for registration.
  • Fitting CRN registration will expire 10 years from the date of the first registration or latest renewal, not 10 years from the date of the last addition.
  • Each province has a ‘final call’ for their region as to whether they want to accept or merge an addition to a CRN or not. Ontario does not have a final call for Alberta. If, for example, Ontario requires X# of FEAs but Alberta later requires more FEAs or other requirements, then despite previous registration in Ontario, Ontario will subsequently need to accede to Alberta’s request and reconsider the application again if the addition is to be considered for registration in Alberta. That is why it is important to first register equipment in the province that has what is perceived to be the most challenging requirements for any particular application. And similarly, Ontario is under no obligation to merge fittings registered in Alberta as an addition to an Ontario based CRN.
Answer Key

Harmonizing CRN Process Benefits Q&A

In this space, some questions posed by customers and industry are published in case others have similar questions. Anonymity is preserved. Check back for updates and new correspondence.

Dear Cammar,
I read your article about harmonizing the CRN process, in which it is stated that we need CRN’s. I am puzzled about the benefit to the general public safety of this process for fittings, seeing that this is only practiced in Canada. How do we compete with countries that don’t have CRN process? How can we claim to have a higher standard of safety, when the rest of the world manages quite fine without CRNs for fittings? How do we produce a compliant design when equipment is available but without a CRN that the manufacturer does not see the need to apply for and register their product?
I look forward to hearing from you.
Concerned Ontarian

Dear Concerned Ontarian,
Thanks for your email.
Governments in Canada deem the CRN process worthwhile and pursuant to public safety, given that CSA B51 is referred to in Canadian legislation. CSA B51 helps to ensure through third party oversight that pressure equipment is designed, built and tested to codes and referenced standards that have, through careful collective deliberation, been written to help ensure public safety by using adequate safety margins and other considerations.
These codes and standards are adopted by legislation and stipulate minimum requirements. In some foreign locales where CRNs are not required, designs do not always meet minimum code and referenced standard design philosophies. And when they do not, designs are therefore less safe than those that do.
In Canada, pressure equipment designs meeting legislated requirements are competitive and registerable.
Public safety is, I’m sure you would agree, of paramount importance.