CRNs - Frequently Asked Questions

Frequently Asked Questions - the most recently updated questions are listed first.

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.

For example if B31.3 is used as the design code then: "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)

For example if B16.5 (pipe flanges and flanged fittings) is used as the design code then: "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)

For example if B16.9 (factory made wrought buttwelding fittings) is used as the design code then: "Hydrostatic testing of wrought fittings is not required by this standard." (10)

For example if B16.34 (valves - flanged, threaded and welding end) is used as the design code then: "Each valve shall be given a shell test..." (7.1)

For example if VIII-1 (pressure vessels) is used as the design code then: "A hydrostatic test shall be conducted on all vessels..." (UG-99(a)).

Does my product need a CRN? This is the most difficult question of all. It depends upon whether your product is a vessel, fitting or piping system. It then depends on what it contains and at what pressure and temperature. Pressure vessels are the easiest to determine (check the charts below).

Fittings and piping systems can be very difficult to determine. Requirements also vary from province to province. Additional information on fittings can be found on our website: Fittings - Do I Need a CRN? Further information on Piing systems can be found on the submenu: Piping - Do I Need a CRN?

What happens if I don't get a CRN? There are a large number of fittings, piping systems and pressure vessels in use in Canada that require CRNs but do not carry them. These products are often uncovered during authorized inspector visits or insurance audits. Some customers will require CRN on all vessels, piping and fittings before they will buy. 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 can not be registered then it must be replaced.

I can't get my jurisdiction to answer my questions - what should I do? First ensure you are giving them all the information they need to answer your question? We suggest submitting the application in writing along with all required information. Include a purchase order and required up front fees the same as if the product is being registered. Ask for a response in writing. Having a letter on file stating that your vessel does not need registering is useful during an audit. Saying that you talked to someone and they said that your vessel was okay will not work.

What is the difference between a fitting a piping system and a pressure vessel? How does it affect how it is registered? A fitting can be a small pressure vessel, or a valve (of almost any size) or other items like flanges, expansion joints or hoses, strainers measuring devices, pressure relief devices or other miscellaneous components. For a fitting, the manufacturer can do their own inspection. For a pressure vessel, an authorized inspector needs to do the inspection. Fittings require statutory declarations and so can be more complicated and expensive to register. Fitting calculations and drawings do not need to be updated every year as code rules change but the CRN expires after 10 years.

What paper work do I need to get a CRN for a Vessel? A complete product drawing including operating conditions and materials. A set of code calculations done to ASME code. The application form from the province. Proof of quality control system. Up front application fees if required, Patience. You are registering the design, not the finished product. Your authorized inspector will be checking your weld procedures and material certs , not the jurisdiction providing the CRN. Note some provinces have special paper work (especially on piping) that has to be filled out and signed by the authorized inspector prior to shipping the finished product.

What paper work do I need to get a CRN for a Fitting? Same list as above for a vessel, plus the required statutory declarations.

What provinces will I need to register my product in? Your product needs to be registered in all provinces where it will be used. (Common problem - the province where it is used might not be the province where it is first shipped to.)

Is my Quality Control system acceptable? ASME U stamps are required for pressure vessels. Various quality control systems are acceptable for fittings such as ASME U stamps and ISO 9001 certificates.

Do I need a professional engineers stamp on my submission? For fittings - no. For pressure vessels - it depends on the province - see the provincial information below. Important: Ontario requires an Ontario engineers stamp on all submissions. All other submissions will be returned.

How long will it take to get a CRN? How much will it cost? Is it worthwhile? This varies with the jurisdiction, or if all jurisdictions are required. For single provinces with simple vessels or fittings, it can sometimes be done in a week (provincial expedited fees usually apply). For Canada wide registration of more complex products, ½ year is not unusual once the registration process is started; the shortest registration we assisted with was 3.5 months, the longest 1.5 years.

How long can I manufacture Pressure Vessels to my CRN? The CRN for a pressure 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. Do I need to update my Pressure Vessel calculations with each code revision? Manufacturers have to re-run or review the calculations each year to determine that the design is still valid. The authorized inspector confirms that the calculations are current or reviewed. (This is the same requirement for National Board fabrication.)

What Materials can my Pressure Vessel be made from? Pressure vessel materials listed in ASME codes are made to published specifications (or recipes). The materials are shipped with material test reports guaranteeing that each batch complies physically and chemically to the specifications. These materials can be found listed in ASME IID (and some other code locations). The listing provides the allowable stresses at various operating temperatures.

Many other materials exist but they are not listed in the pressure vessel codes. They are unlisted. Except in unusual circumstances, they can not be used for a pressure vessel, even if they are built to a published specification and tested. An example is rectangular structural tubing. It is forbidden as a pressure vessel material even though it is built to a published specification complete with physical and chemical properties. Its shape would make it very useful. Instead we weld pieces of formed plate together.

What Material can my Fitting be made from? More freedom is available to a designer of fittings. There are more codes to choose the material from (IID, B31.1, B31.3 etc.) and there are rules that allow unlisted materials made to published specifications with both physical and tensile specifications to be translated into code use (BS, EN, ASTM etc.). The translation process is easiest for use of materials at room temperature. At elevated temperatures, hard to find creep properties are required.

Cautionary note on unlisted materials: Many CRNs exist for fittings that are made from unlisted materials that do not have published chemical or physical specifications and the manufacturer is not obtaining material test reports on each batch of product produced. A few provinces are still accepting new registration for these products, sometimes depending upon who does the review. Other provinces absolutely will not accept them.

Can I make my Fitting from plastic? Yes - the stresses in the part will need to be calculated and compared to a published HDB (Hydrostatic Design Basis) allowable stress. HDBs can be found for a few plastics in ASME B31.1 and B31.3. Other plastic materials not listed can be used if the HDB allowable stress is determined. The HDB test is long term (2 years) and expensive. Once the HDB for the material is known, any shape of product can be made. For complex shapes like valve bodies a process like finite element analysis will be required to determine the operating stresses and make sure that they are below the HDB allowable stress.

Can I use Finite Element Analysis (FEA) to design to VIII-1 (Pressure Vessel Code)? Important Note: FEA can not be used to replace mandatory code rules (classical calculations) found in VIII-1. (The same comment applies to Roark's formulas, you can not use it to replace code rules.) It would be nice to use finite element analysis to calculate the stresses that are actually found in items like flanges, nozzles or heads. For these items there are mandatory code equations that are not based on actual stresses. These rules must be followed. Once the rules have been met it is acceptable to use FEA for additional analysis to determine actual stresses for reference use.

Example: the program Nozzle/Pro from Paulin Research Group (http://www.paulin.com/) does an excellent job of calculating the actual stresses in a nozzle using FEA methods. It sometimes calculates that a nozzle can be built with smaller re-pads than the code area replacement rules allow (UG-40 etc). However, the regular code area replacement rules must be followed. Using the reduced size re-pad is not allowed. Nozzle/Pro can be used to calculate the effect of added nozzle loads which the code can not do and WRC 107/297 can not do accurately.

Finite Element Analysis is indispensable for shapes that are not covered by the code. For VIII-1 vessels our office standard is to use the allowable stresses from IID table 1A and 1B for the stress limits instead of 2A and 2B which are specified by VIII-2. The code is not clear on this aspect - some people use the higher allowable stresses found in tables 2A and 2B (see VIII-1 U-2(g)).

Further point - a pressure vessel ends at the first welded joint in the nozzle or at the first threaded or flanged connection (see U-1(e)(1)). Covers and other attached items can be handled as parts of piping systems under B31.3 (see next question) with more design flexibility.

Can I use FEA to design to B31.3 or B31.1 (Piping or Fittings)? FEA is allowed under design code B31.3 section 304.7.2(d), but not to replace rules found in the B31.3 code (see VIII-1 above). There are fewer design rules in B31.3, so many common items can be designed by FEA. Note: B31.3 table 1A stresses are to be used, Not IID tables 1A, 1B, 2A or 2D.

For B31.1 refer to 104.7.2(D) - same idea as B31.3.

What is required for a Finite Element Analysis submission? FEA submission requirements have been clarified by ABSA - ABSA Guideline. The requirements are not simple, but they are being adopted across Canada. See the FEA section on this web site for examples of FEA reports that have been accepted across Canada.

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.

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.

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.

My product has glass components - how do I register it? There are no code rules for glass components (sight windows etc.). The manufacturer's temperature and pressure ratings will be used - they need to be included with the submission.

How can I get my product registered across Canada? Which jurisdiction should I start at? See the section on our main CRN page on how registration across Canada works. The choice of first province is important and can have a huge effect on the total cost and time of registration. The first reviewer takes the blame if any other jurisdiction complains about a product they feel should not be registered. Because of this, no-one wants to be first. Some have requested never to be used for a start to Canada wide registration. The work load of different jurisdictions also changes. Call us.

I need to change the design of my vessel. Do I need to get it re-registered? Typically the answer is yes if the design calcs change, no if they do not. For example, you add another nozzle to a vessel identical to one that already exists, and the nozzles are far enough apart that they do not interfere - no new CRN is normally required. If the nozzle requires new calculations, then normally the design will need registering. Enquire with your jurisdiction for more info.

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 will probably not need to re-register it. Call your jurisdiction.

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.

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 can not be found. A photograph of the nameplate is required and the manufacturer's data report is required. A used vessel might need some inspection like ultrasonic testing to prove that the vessel is still adequate. The installation location will be required. (People have been killed in Ontario importing used high pressure vessels and using them without registration or inspection.)

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? The worst vessels to register are done in codes other than ASME with non ASME materials.

I am designing a piping system that needs to be registered. What do I need to do to get it registered? Similar to a vessel, you need a calculation set, drawings and also a list of all components in your piping system, and their CRN numbers.

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...

Do I need to label the CRN number on my vessel? Yes - stamp the CRN number on the code nameplate. On my Fitting? No.

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.

I can't get my product registered but my competitor who makes the same product the same way I do succeeded - is there anything I can do? Plan A - CRNs are not permanent - for a fitting it will expire after 10 years. You can wait until they try to renew and see if they get accepted. Renewal is not a rubber stamping process - full engineering documentation the same as an original submission is required. Plan B - Document and complain. CRNs can be revoked if you prove that a manufacturer is not following the rules of the codes that they claimed when registering. Start with the first province of registration - if that province cancels then all the other provinces will automatically be cancelled. Because we at PVEng Ltd. believe that there already is enough pain built into the whole CRN system by its design, we will not help companies with this un-registering process.

Pressure Vessel Engineering Limited
120 Randall Drive, Suite B
Waterloo, Ontario, Canada
N2V 1C6

Phone - (519) 880-9808
Fax - (519) 880-9810

(c)2010 Pressure Vessel Engineering Ltd.