CRN Piping Sample

File: PVE-6950, Last Updated: Feb 4 2014, By: LRB, JLL, CMB


Registration of Piping in Canada is difficult. The rules are complex and vary by province. This sample is intended to help someone with little or no experience registering piping in Canada. It is a simple heat exchanger piping system designed for an Ontario installation. One size does not fit all. Throughout this article, differences in provincial registration requirements are discussed.


Drawing of the sample piping: P&ID and spool drawings. These drawings and the calculation set can be downloaded

Quick Links

Do I have a piping system? (All Provinces)

What is piping? According to ASME B31.3 Process Piping 300.2: piping: assemblies of piping components used to convey, distribute, mix, separate, discharge, mete, control, or snub fluid, flows.

Occasionally it can be hard to determine if you are dealing with a piping system or a vessel. Differences in opinion can exist. Another quick guide: “Vessels do something, piping moves fluid from one location to another”. This sample project is clearly a piping system. The heat exchanger gets registered separately with its own vessel CRN number. The exchangers PRV is located in this piping system.

Decision: Scope of Registration (Every Province is Different)

Each province has its own unique set of piping requirements. Where they have been put in writing they can be found in flowchart form at: CRN Piping Flowcharts. It can be hard to determine whether a piping system needs registration or not and getting provincial assistance is very difficult. Where there is a lack of clarity, customers often ask for piping registrations even when it is not required. The cost and delay of registration is balanced against the future risk of dealing with non-compliant piping. Occasionally jurisdictions will refuse to register a piping systems based on the use. This provides written documentation of the exempt status.


Decision tree used to determine the scope of registration of the high temperature lines in Ontario. The high temperature lines need registration.

Often only part of a piping system needs to be registered. For this example based on temperature, pressure, diameter and working fluids only the high temperature part of this system needs registration. The above image shows the decision tree to determine if the high temperature piping needs registration.


Decision tree for cooling water lines. The cooling water lines do not need registration. Open a larger version.

Repeating this for the low temperature piping indicates that it does not need registration. This scope would be different for other provinces; in general Ontario has the most inclusive scope of registration, and Alberta the least (Only the heat exchanger would need registration in Alberta). This decision tree is not required with the submission. The submitter is responsible to determine if registration is required. The reviewer judges if the submitted documents adequately support registration, and if so reviews the design and issues it. Although the low pressure piping does not need registration, sometimes customers request that the whole system be registered.


Scope of registration shown on a copy of the submission drawing – (Method used is acceptable in all provinces except Alberta).

There is no official way of indicating the scope of registration, but it is useful to include this highlighted scope with the submission package (All provinces except Alberta).

For Alberta two problems exist – 1) ABSA is not able to process color documents and 2) The submission drawing has been duplicated, so now two different drawings exist with the same drawing number so they cannot both be controlled documents and the registration stops. See below under “Line List (Alberta)” for a simple method of showing the scope of registration in Alberta.

Decision: Piping or Fitting (All Provinces)

Where possible, registering piping as fittings has advantages. Per CSA B51 2009 – 11.4:

[A fitting can be] a series of components (including piping components) joined together to form a single fitting, provided that the diameter of any component does not exceed 152 mm (6 in) and the total volume of the fitting does not exceed 42.5 L (1.5 ft3) can be registered as Category H fitting.

Piping can only be built for one installation address. Fittings can be installed at any address for the province it is registered in.

Piping must be signed off by an authorized inspector. Fittings can be signed off by the shop’s inspector according to the in house QC program.

The Sample shown here is built as a piping system for one off use at one address only. If the manufacturer of this sample later builds another copy for a different address, the registration process will be repeated. Some jurisdictions are in the process of developing workarounds for this. Some are allowing oversized fittings; some are creating special classes of multiple build piping systems. Others do not have a workaround yet and require repeating identical registrations, even for use in the same province.

Drawings and Calculations (All Provinces)

It is not possible to register a piping system without fabrication drawings and code calculations. The calculation set determines the required wall thicknesses and welding details to safely contain the operating fluids. The fabrication drawing is sufficiently detailed to allow purchasing, fabrication and testing to proceed without need to reference the calculation set.

Most registered piping in Canada would not need registration anywhere else in the world. For manufacturers new to these requirements, it is useful to pretend that piping systems are like registered pressure vessels, only with much more paperwork.

In this set there is both a P&ID drawing and pipe spool drawings. With enough details on the P&ID drawing, the piping spool drawings could have been eliminated. However it is often easier to get the fabrication details right when the spool drawings are included. With this set of drawings, there is not enough detail on the P&ID to support a submission without the spool drawings

It is understood that field dimensions on a piping system can be different from the registered drawing. If the registration is based on a P&ID, many preliminary and final dimensions will not even exist.


Support calculations are rarely requested by reviewers, but support distances often are. This requirement can be found in ASME codes B31.3 321 “Piping Support”

321.1.2 Analysis. In general, the location and design of pipe supporting elements may be based on simple calculations and engineering judgment. However, when a more refined analysis is required and a piping analysis, which may include support stiffness, is made, the stresses, moments, and reactions determined thereby shall be used in the design of supporting elements.

Much of British Columbia and some other Canadian areas are in strong seismic zones. From British Columbia’s Pressure Piping Registration and Inspection the following requirements apply: “4(d) ASME code calculations for expansion, flexibility and support for pipe diameters exceeding NPS 3.” From our experience we take this to include the requirement to supply seismic calculations using some method like Caesar. Various appropriate methods can be used to prove the supports from hand calculations through to Finite Element Analysis.

Line List (Alberta)

Alberta requires a separate line list. This is a controlled document complete with drawing and revision control and complete with a P.Eng. / P.E. stamp.


A successful line list format for Alberta submissions

As required by ABSA (Submission Requirements for Registration of Pressure Piping Designs in Alberta), the list includes: line identification with size and schedule, pipe material and corrosion allowance; fluid, design and test pressure; maximum and minimum temperature. In addition to the official requirements, we have also found the following to be useful with Alberta submissions: Drawing number and page containing the line if more than one page; flange class and NDE is also specified. In the last column we have added the registration status of each line to avoid submitting a highlighted drawing (See Scope above).

Although mandatory for all submissions to Alberta, this line list is also a useful document for complex submissions to other provinces. Most provinces would consider this piping system with only two temperature pressure ratings simple enough to not require a line list.

Overpressure Protection (All Provinces Except Alberta and Saskatchewan)

Overpressure protection for piping installed in Canada (other than Alberta and Saskatchewan) can follow the standard requirements of ASME B31.3 301.2.2:

301.2.2 Required Pressure Containment or Relief

(a) Provision shall be made to safely contain or relieve (see para. 322.6.3) any expected pressure to which the piping may be subjected. Piping not protected by a pressure relieving device, or that can be isolated from a pressure relieving device, shall be designed for at least the highest pressure that can be developed.

(b) Sources of pressure to be considered include ambient influences, pressure oscillations and surges, improper operation, decomposition of unstable fluids, static head, and failure of control devices.

(c) The allowances of para. 302.2.4(f) are permitted, provided that the other requirements of para. 302.2.4 are also met.

This use of overpressure protection by system design is usually but not always accepted by reviewers. If using PRVs, problems include the use of non ASME certified pressure relief equipment is not permitted. Be careful where your PRV exit line flows to – there cannot be any valves blocking the way. Regardless of the target province it is a good idea to budget for extra pressure protection devices.


This metering pump piping which requires registration in some provinces shows a typical problem: valves exist between the exit of the PRV and the supply tank where the relieved pressure is flowing to. The argument that the pump cannot be pressurized when the supply valve is closed is not accepted by all reviewers. Also note that the relief valves from these positive displacement pumps must be ASME certified, not other commonly used backpressure valves.

The sample drawing clearly shows the setting of each PRV, and it can be seen what equipment is being protected. This is usually adequate for submission purposes. Optionally the Alberta PRV list can be included if it helps clarify the submission.

Overpressure Protection (Alberta and Saskatchewan Only)

Currently loud howls of protest are being heard with regards to overpressure protection. The odds are high that you will add pressure relief devices to what you thought was a finished design. ASME B31.3 301.2.2 allows the use of piping without pressure relief devices, but these two provinces have guidelines against the practice. Saskatchewan’s is the easiest to read: “The use of overpressure protection by system design (OPPSD) is an exception to the standard” (TSask IP-2011-03-001 – a document primarily concerned with pressure vessels). Alberta has a difficult to read guide to when PRVs are required. Getting assistance on this topic is very difficult.  Most applicants give up and use PRVs.


Not allowed in Alberta. This 10 cubic inch pulsation damper is treated as a pressure vessel in Alberta. Because of its inlet valve, it is isolated from the PRV. The failure mechanism: an operator closes the valve while the damper is pressurized; a fire occurs in the building with no way to vent to damper; the damper creates a hazard to firefighting personnel. A way of protecting the damper from overpressure must be provided same as if it is a larger pressure vessel. Here the solution is simple: remove the damper isolation valve.

Additional Overpressure Protection Requirements (Alberta Only)

From ABSA Submission Requirements for Registration of Pressure Piping Designs in Alberta

“6. A list of pressure relief devices, including their set pressures and identifying all the pressure vessels or boilers protected by each device. The list shall identify which sheets of the P& IDs the pressure relief device is located on.”


PRV list for Alberta

For this example there is only one PRV and it protects all the registered piping. Still a separate list is required. Again this is a controlled document complete with drawing and revision control and a P.Eng / P.E. stamp. A copy of this document can be found in the resources section.

CRN Numbers for All Fittings (All Provinces)

The hardest part dealing with the CRN system is the need to source components registered to the province of installation. If an American fabricator purchases flanges, elbows and tees randomly from a vendor, by chance about 30% will carry a valid CRN for use in some Canadian jurisdictions. Manufacturers need to be willing to substitute parts or change vendors to get the required CRNs. Rarely, a burst test can be used to prove a component that just cannot be registered (not in Alberta).  Most jurisdiction reviewers will ask for a list of CRN numbers. Our recommended format:


CRN list in a successful format. (All CRN numbers are fictitious.)

The format shown here is not mandatory, it is what has been successful for us. Items to note:

  • The list has a drawing number to tie this into the production drawing, and it has a revision control number.
  • The catalog rating or class is a listed requirement for Alberta. It is still a minority requirement for Ontario reviewers, but for Ontario and other provinces, its requirement is increasing. Regardless of requirement, at some point you need to check that all fittings have been correctly specified for the design conditions.
  • The material specification is the full ASTM designation. This is “A-182 F304” (or A-182 304) – not just “304”. Also it is no longer permissible to use the ASME specifications on piping submissions: some reviewers would require “SA-182 304” to be changed to “A-182 304”. Special care needs to be taken with boiler external piping to distinguish between the B31.1 and Section I materials which must be specified differently.

As mentioned above, listing the CRN number is not part of any official submission requirement, but the majority of reviewers require it.

No jurisdiction requires the expiration date for the CRNs, but some reviewers check this, which could impact your submission. We suggest caution if the expiry is within 1 year of the submission date. For example the Alberta requirement is a statement that all fittings used are “suitable for the specific design service conditions and are registered with ABSA”. This is a way of tracking that all fitting CRNs are still registered. Check out Ontario’s Piping Systems Installation and Test Data Report:

I, the undersigned, declare that the described pressure piping system approved under design registration number ___________________ complies in all respects with the regulations for construction, installation, testing and inspection as required by Ontario’s Technical Standards and Safety Act, Boilers and Pressure Vessels Regulation, CSA B51 and/or B52 and the applicable Pressure Piping Code of Construction. Valves, piping and fittings in this installation have been visually inspected to ensure that they comply with Code requirements for identification. All valves and fittings have been duly registered, are of correct schedule and/or ANSI service rating and compatible with the required service condition.[emphasis added]

At some point you need to prove that all the components have CRNs, and the earlier you get this over with the better.

Note that pipe does not carry a CRN as it is calculated. Although elbows and tees are calculated, they also need CRNs (The CRN proves that the B16.9 fittings can be calculated as pipe)

Engineer Stamp Required

All provinces require P. E. or P.Eng. sign off as outlined in B31.1 and B31.3 (see B31.3 301.1 Qualifications of the Designer). In addition, Saskatchewan only allows Saskatchewan P.Eng. Stamps, and Ontario only allows Ontario P.Eng. stamps. All other provinces will accept any qualified Canadian P.Eng. or North American PE. (Note: Pressure Vessel Engineering Ltd. have stamps for both these provinces in our office.)

QC Requirements

Our piping page has a list of QC requirements as it varies by province. The scope of Ontario’s B51 certificates are restrictive. For example, holders of an Ontario B51 piping certificate are not certified to build fittings for use in the same piping systems. The fabricator would have to hold a separate Ontario B51 fitting certificate or other QC certificates like ASME or ISO. Other provinces are more flexible.

Except in very special circumstances, consider it impossible to register piping without the correct certification.

Submission for Registration (All Provinces Except Quebec)

Registration is handled the same way as a pressure vessel in Canada. The application is examined by a reviewer. Any missing information is requested. Design shortcomings are fixed. Usually the process takes a few weeks to a couple of months, but be careful, depending on the assigned reviewer and province it can take over a year. Do what you can to get all of the above mentioned required information up front.

See the piping page for more details on the required paperwork which is different for each jurisdiction. Officially, fabrication must wait for the registration to be complete, but many projects cannot wait. If the manufacturer must proceed with fabrication, they risk rework or scrapping a system if design or qc changes are required.

Quebec Submissions

There is no review process for Quebec piping. The piping is built and shipped as with any other province, filling out the correct provincial forms. The drawing, calculation set and quality documents are shipped with the pipe to be inspected by the onsite Authorized Inspector.

Fabrication: (Pretend it is a Vessel)

Unless it is a fitting, an Authorized Inspector sign off is required on the project. That means that the AI must review before fabrication starts, during fabrication, and provide the final sign off (just like a pressure vessel). The sign off is done on paperwork appropriate for the target province. Each province has different forms – see the piping page for forms.

After the piping system is shipped and installed it will be signed off by the sites Authorized Inspector prior to start up – again just like a pressure vessel.

Unlike vessels, the piping does not get National Board registered, so what happens to the paperwork? From BCSA (British Columbia): “All applicable piping system construction data reports shall be available for review by the Safety Officer at the installation site.” In other words, the paperwork ships with the piping.

Oops! I never registered it!

Many Canadian piping systems that need registration never get it. Older piping systems are ignored under the assumption that someday all will be replaced and the replacement will be registered. Problems usually show up at worksites that are under regular inspection of Authorized Inspectors. Someone is trying to install a skid containing piping and the provincial paperwork cannot be found. A long process of rework / inspection is started. Did an Authorized Inspector witness it? Do the components have CRNs? Were the welders qualified? Was it built under a QC program? The amount of work varies by province: Easier in Ontario, almost impossible in Alberta. Less expensive piping systems (think less than $10-20,000) get replaced.


A partial list of useful piping CRN parts can be found on our website. The ACI website has a list of all CRN components registered in Atlantic Canada. This is a good start as many components registered with ACI are also registered in other Canadian provinces. Look on the “Search CRN Registration Database” link.

Unfortunately the available supply of registered components can be disappointingly sparse, and only ACI and Alberta provide public listings. As of this date the information is organized in a manner that makes it difficult to do more than just verify that a CRN exists for a known manufacturer. As the CRN system approaches maturity we hope more jurisdictions will make it possible for end users to find parts registered in their provinces. When these listing are created, they need to go further to allow a designer to source registered components even when the manufacturers name is not known.

The Excel spreadsheets used to make the Line list, CRN list and PRV list can be downloaded here.

Visit our piping page to get flow charts of the provincial piping requirements and the required forms.

Visit our Provincial contacts page to get contact information, review time estimates and review rates.

We help companies with all their piping registration needs – see our advertisement below.

Author’s Opinion

When talking to potential customers about piping registration we immediately encounter an attitude: they do not believe that this CRN system is a good way to ensure safety. The jurisdictions have more than a century of accident reports and safety studies. It is unfortunate that they have not done a better job of persuading people that although our system is the most difficult in the world, it is also intended to be the safest.

With a lack of belief in the safety comes another belief: the CRN system is protectionism or a money grab. This leads to the problem: the desire to do a bare minimum amount of work necessary to get a job registered. Unfortunately this approach is the hard way to get a Canadian piping system registered. A steely determination to surmount all obstacles while maintaining the integrity of the design is essential to success. Cutting corners will not do.

The desire to do the minimum leads to not following the written rules from jurisdictions as stated in various standards or legislation. The written rules also have unwritten companions like the CRN lists that have been mentioned above and others like the Alberta restrictions on overpressure protection that has been enforced for several years before it was finally documented. This sample covers some of the common required knowledge, official or not.

Our customers have extremely strong opinions that in this age of free trade it is not appropriate for any organization to mandate the use of components that only they can approve. But this is legal. Free trade agreements allow products to cross borders duty free. They do not guarantee the right to use the product once it arrives on the other side. Designs have to be done to North American standards. Fittings must have CRNs for the province they will be used in. Only the jurisdictions are allowed to issue the CRNs.

People don’t like substituting components that they are used to using in a design just because they do not have CRN numbers. Changing proven existing designs is trade-off with a rules based safety program like this. Lousy designs get improved and proven designs get turned into prototypes. We see both every day, you don’t get one without the other. A manufacturer must be willing to change their design or get all of the fittings they use registered to obtain a piping registration. Experience based designs are not considered for registration.

The requirement to use local engineers to sign off on some projects for Ontario and Saskatchewan is not thought of as protectionism by the engineering societies. Because registration is done by province, the provincial engineer’s societies have declared that local engineers must be used. Most jurisdictions have been approached with this requirement; however some have been successful in fighting it off. Expect the jurisdictions to continue to be pressured and perhaps more provinces to require only local engineers in the future. If these rules and the registrations were Canada wide in scope, this protectionism would not be possible. Getting a local P.Eng. to sign off on a project can be a significant problem for many manufacturers. See resources below.

Yes it was easier 5, 10 or 15 years ago. The jurisdictions continue to create more complex rules or enforce other existing rules for the first time. The rules continue to diverge between provinces. Backlogs are longer than we have ever experienced before. This varies hugely with the assigned reviewer, but also with the province that you are dealing with. There is nothing you can do about the reviewer you have been assigned. With the potential of long review times it becomes critical that you maximize your chance of getting your submission accepted as submitted. Although it is impossible to guarantee this goal, it is possible to get closer by following the methods outlined here and not looking for shortcuts.


Do this less often! With the correct information and attitude you can have more success with your Canadian piping registrations.

Wishing you the best of luck with your piping registration, Laurence Brundrett, P.Eng., President, Pressure Vessel Engineering Ltd.

Getting Help from a Consultant (Advertisement)

We at Pressure Vessel Engineering provide assistance in the design and registration of pressure vessels, fittings and piping systems. We carry many P.Eng. stamps that allow us to submit to any province. Although we would be happy to assist you in your next project, we can only do some of the work for you. We can provide drawings, calculation sets, fill out provincial paperwork and submit / follow up / provide technical support with the jurisdictions. The catch is that we are not process engineers so not all of the work can be done by us.

We will not ask you to like the CRN system, but we will help you comply with all of its requirements. Many companies use us for all of their Canadian registration needs.