Registration of Fittings - Changes Since 2005
PVE-
Last Updated: October 7, 2011
By: LRB
The requirements to register fittings have changed significantly. Around late 2004/early 2005 we started getting phone calls from companies having difficulty renewing their CRN registrations in various Canadian provinces. We started doing calculations and drawing sets to get lines of valves, sensors and other pressure products registered. Prior to this time we did almost none of this type of work.
What had changed? Why did these manufacturers need engineering help now, and not before? The manufacturers were providing the jurisdictions what they had always provided: signed statutory declarations; a copy of their product catalog; and a copy of their ISO or other QC certificate. But no longer was this enough to get their products registered. They now had to send in additional proof of burst tests and/or calculations along with detailed product drawings - the same requirements as if they were registering a pressure vessel.
The 1997 B51 standard outlined the requirements to get a CRN for a fitting (B51 - 4.2.5): As a minimum the following documentation in support of an application is required:
- Statutory declaration
- Designation of the code or standard
- Material specifications
- Maximum allowed working pressure
- Maximum working temperature
- Dimensions
- Detailed calculations and/or copy of proof tests witnessed by an Authorized Inspector acceptable to the regulatory Authority.
(not listed) Proof of an acceptable quality control system must also be shown
By the 2009 edition, the list had changed slightly but not significantly. The Canadian code had not changed; the jurisdictions decided it was time to enforce it.
Prior to 2005 CRNs were routinely being issued without items (vi) and (vii) above. It was so easy that the services of a company like ours were not required. As we did more fitting renewals, we found that there had been an earlier even easier registration method - submit a statutory declaration and a catalog (without proof of the QC program). The original intent of the statutory declarations became apparent - the manufacturer was swearing that the QC program and the calculations existed, but were not including them in the registration package. Companies still have to fill out statutory declaration forms, but their purpose is no longer to declare that the missing information exists - all information must be provided.
This change in requirements caused significant difficulties for some manufacturers as widely used clauses such as B31.3 304.7.2(a) - extensive successful service -were no longer acceptable. Other difficulties included providing material specifications acceptable under B31.3 323.1.2 and getting previously run proof tests accepted under the requirements of Section VIII-1 UG-101. We also believe that some companies were declaring that non-existent calculations or proof tests existed.
The changes resulting from this are twofold: 1) - some products that were previously registered in Canada are not being renewed; and 2) those that are being renewed are being done at a much higher cost. Manufacturers are now spending $10,000 to $50,000 to register a few pages out of a catalog which had previously been completely registered for $3000. The review times are also much longer. It is not unreasonable to budget one year to do the calculations and get Canada wide registration of a series of fittings.
It will be a few more years before all fittings registered under the old methods expire upon their ten year anniversary. At that point will Canada have the world's safest pressurized equipment or will we be trying to cobble together marginal systems from a selection of available parts that is too small?
Registration of Plastic Fittings
PVE-5246
Last Updated: June 17/11
By: LRB
Plastic pipe that needs to be registered can be calculated to code rules found in B31.1 or B31.3. But a plastic pipe needs plastic fittings - how can they be registered? Plastic fittings are among the most difficult to get registered under the CRN system.
Burst Testing:
The good news is that TSSA has a standard to cover the burst test pressures used for unlisted materials (like plastics):
GUIDELINES FOR THE REGISTRATION OF NON-NUCLEAR
FITTINGS IN THE PROVINCE OF ONTARIO (here):
Burst test factor of safety from the guideline (Appendix D):
4 - for all materials not listed below
6 - cast iron
10 - glass
10 - non-metallic, non-automated fabrication process
|
The bad news is that it is very hard to get a reviewer, even one from Ontario to accept the factors listed. Although moulded plastic parts are made with automated processes justifying a 4x factor, we invariably end up having to use a 10x factor. However we have seen rare cases where 4x has been allowed on moulded parts in Ontario. See more on CRN burst test problems here.
When more than one grade of plastic is used, each grade needs to be tested. That, combined with the need for conservative safety factors can make using burst testing unacceptable.
Calculations/FEA:
B31.3 provides allowed stress levels for calculating plastic fittings. B31.3 Table B-1 and B31.1 table III-3.2.1 provide HDS allowed stress levels for many common plastics. The Plastics Piping Institute has a larger list of HDS values here. Where the B31.1/31.3/PPI listings overlap, identical HDS values are provided. Most reviewers Canada wide allow the PPI values of HDS to be used with the occasional exception of some Alberta reviewers.
With an allowed HDS, the fitting can be calculated either by using standard code rules or as shown in the illustration above, by FEA. Simple or complex fittings can be registered at a higher operating pressure than would be allowed by burst test. When more than one grade of plastic is used, only the weakest has to be analyzed.
Registering Steam Heated Molds
PVE-5242
Last Updated: June 17/11
By: LRB
In some provinces, heated molds need to have CRN registration. For example, steam heated platens and steam heated cavity molds need CRNs in Ontario. Tire molds with steam cavities are registered in Quebec. Each province has its own requirements - contact your local jurisdiction.
A designer of a mold or platen would not normally consider the pressure vessel design rules unless specifically required to do so. The primary stresses in the mold normally come from the use of the mold, not from the steam in its heating passages.
VIII-1 U-l(c)(2) Based on the Committee's consideration, the following classes of vessels are not included in the scope of this Division... pressure containers which are integral parts or components of rotating or reciprocating mechanical devices... where the primary design considerations and/or stresses are derived from the functional requirements of the device.
I interpret this passage to mean that you can use the code rules to design these items if you like, but don't be surprised if they prove inadequate.
The registration process:
- The mold is usually registered as a fitting based on the inside volume of the passages being less than 1.5 cuft. As a fitting, a statutory declaration must be filled out and declared by someone with an appropriate quality control program for manufacturing a pressurized fitting - which can be an adventure for a mold manufacturer. This is even more difficult for a mold that is in service with uncertain lineage.
- The mold is not built to ASME code rules, so the material will normally not be ASME listed. As a fitting, the material can be adopted if the tensile and yield properties are known or can be determined by testing. See Unlisted Materials for more information on using unlisted materials.
- Applying code rules can be interesting. Typically a platen or mold will have a number of gun drilled heating passages. These passages will have intersecting passages to connect and direct the flow of steam and condensate. The passages are surrounded by material that could be considered to be the wall of a pipe. The intersecting passages could also be considered to be a header to branch pipe intersection. The mold ends up being calculated as a piping system!
Tire molds have more complex internal cavities that require more difficult calculations. The calculated code stresses from internal pressure usually end up being a small fraction of the stresses that the mold experiences during operation.
Registering a steam heated mold shown first as a mold, the passages in the mold, and finally passages modeled as pipes using available material. The equivalent pipes and intersections are calculated to piping code rules.
Moving or Changing Your Company Name?
PVE-4045
Last Updated: Feb. 10, 2012
By: LRB
Q - If your company changes name or address, do you need to update the registration of your fittings?
A - Yes.
In Canada, fittings are considered to be small pressure vessels with the permission for inspection granted to the manufacturer under the control of the manufacturer's quality control program, as specified and sworn in the statutory declaration. When the companies name or address changes, the statutory declaration on file with the provinces is no longer valid. The statutory declaration for each CRN in each province needs to be updated.
Changing the brand name to be affixed on the product is another case where the statutory declarations need to be updated. This case is not discussed below.
The following is required to update the CRN applications:
- A cover letter explaining that your corporate name has changed or that your company has moved and that you are updating your registered products as a result.
- A copy of the updated QC certificate issued in your new company name or new address (this is the plaque that hangs on your wall).
- A copy of the original proof of registration (the original statutory declaration returned by the jurisdiction with the CRN number on it, or the letter of registration - whatever was returned by the Jurisdiction when the fitting was originally registered).
- The correct number of revised statutory declarations covering the same scope as the original statutory declaration.
- Additional requirement for Alberta only - the entire original drawing and calculation package must be re-submitted.
Process:
Step 1 - get the original jurisdiction that did the first registration on the original CRN to update the CRN using the above listed materials.
Step 2 - included a copy of the updated CRN from step 1 with the above listed materials and send it out to all other jurisdictions.
Additional Information from ABSA:
The following clarification was received from ABSA regarding fittings and vessels.
1. If a fabricator changes the name of the company, what is involved with updating the paperwork at ABSA?
- Fittings - A separate submission for each CRN consisting of a new AB-31 application form, a new QC certificate, two new Stat Decs and a cover letter explaining the name change. No drawings or calculations are required as they are already on file at ABSA.
- Vessels - A letter of explanation outlining the name change and listing all of the affected CRN numbers is all that is required.
2. Can a company own a CRN on a fitting or vessel and have multiple fabricators manufacturer the design for them? Assuming valid QC documentation and Stat Decs (fittings only) for each fabricator.
- Fittings - No. A different CRN number is required for each manufacturer. Each manufacturer must submit their own complete application package (dwg, calcs, Stat Decs, proof tests, etc...).
- Vessels - Yes. However, if a different drawing number is used by different fabricators, they must all reference the original drawing that the CRN covers. The data report needs to show the original drawing number and any other fabricator drawing number should be shown in the remarks section only.
3. Can ownership of a CRN be purchased by one company from another?
- Fittings - This will result in a new CRN being issued to the purchasing company due to the fact that new Stat Decs need to be submitted with a different manufacturing address.
- Vessels - This would work the same as a name change. A letter of explanation outlining the name change and listing all of the affected CRN numbers is all that is required. Although Company A may purchase the registered vessel designs from Company B, please note that Company A is not just purchasing the design, they also accept full responsibility and liability of the designs including vessels that were previously built by Company B.
Costing and Timeline:
For our job where the brand name to be affixed to the product needed to be updated, the re-registration process took about the same amount of time as the first submission with design review - 8 weeks for Canada wide. The renewal fees at about $2000 came in at 85% of the original registration cost. The product was registered Canada wide both times, except for BC and Saskatchewan where it was exempt from registration.
New ABSA Registration Seminar
N/A
Last Updated: March 25/11
By: PVE
ABSA has a brand new seminar for those who submit designs to Alberta for registration- whether you are experiencing difficulties or just want to know more. More information on the times can be found here (look for "Design Registration Seminar" near the bottom of the page). More information on what is covered can be found here).
Cost is $966 per person, 2 days long. See you in Edmonton April 28&29, 2011. More seminars are available in June and September.
Problems Using Burst Testing to Register Fittings
File:PVE-4711
Last Updated: Feb. 25/11
By: LB
An article on common problems using burst testing to register fittings in Canada is available on our website: Burst Testing Common Problems.
Update CRN for Flange Welds
File:PVE-4711
Last Updated: Jan 11/2011
By: LB
 |
|
ASME changed the amount of weld required on a standard B16.5 slip on flanges with the 2009 VIII-1 code update. Per section UW-21 of VIII-1 all standard slip on and socket weld flanges need larger welds on the outside. The larger weld size is not required if there is no room for it on the hub.
UW-21 FLANGE TO NOZZLE NECK WELDS
UW-21(a) ASME B16.5 socket weld flanges shall be welded to a nozzle neck using an external fillet weld. The minimum fillet weld throat dimension shall be the lesser of the nozzle wall thickness or 0.7 times the hub thickness of the socket weld flange. See Fig. UW-21, illustration (4). UW-21(b) ASME B 16.5 slip-on flanges shall be welded to a nozzle neck using an internal and an external weld.See Fig. UW-21, illustrations (1), (2), and (3).
|
VIII-1 Fig UW-21 - flange attachment weld size
The weld size change is mandatory, but do you need to update your CRN? That depends - at the present time Manitoba and Saskatchewan say yes, Ontario says no. We will be adding more jurisdictions as we find out.
| Province |
Update CRN? |
More Information |
| Ontairo |
No |
Will be posted on TSSA's web site |
| Manitoba |
Yes |
|
| Saskatchewan |
Yes |
|
ABSA - Impact Test Information on the Drawing
File:PVE-4711
Last Updated: Aug. 03/2011
By: LB
ABSA requires impact test information to be put on fabrication drawings whenever impact testing is a requirement of the design. This is information that is not usually put on a drawing, but if it is left off, the ABSA review process will be put on hold until it is added.
From ABSA's web site:
Identify which pieces of material must be impact tested and the temperature(s) at which the impact tests are conducted.
Identify whether production impact tests must be conducted for specific welds and the temperature(s) at which the impact tests are conducted.
For materials not impact tested, identify, by reference to the correct Code paragraph, the reason why this material is not being impact tested.**
It is highly preferable that the acceptance criteria (absorbed energy values or lateral expansion) for the impact tests be identified on the drawing since these change with material thickness and strength level.
This information is required to be on the Manufacturer's Data Report and must be communicated by the designer to the shop in some fashion. The means of communication might be notes on the drawing, separate instruction sheets that are referenced on the drawing (and submitted to ABSA with the drawings) or some equally positive means.
** This is also a requirement for all vessels that do not require impact testing, for all jurisdictions in Canada
Why ABSA Cares
As mentioned above, ABSA has stricter drawing requirements for minimum temperature information than other provinces, and reviews minimum temperature calculations in more depth. The graph above shows why. Fort McMurray winter air temperatures drop to negative 40 degrees C (also -40 degrees F).
Should You Care?
Assuming your vessel is not headed for Alberta, should you care about this? An actual example from our jobs: We designed a pressure vessel with a SA-350 LF2 class 1 forging greater than 3" thick. The vessel was designed to -20 deg F. LF2 material comes from the mill already impact tested to -50 deg F. - therefore it meets the code requirements - or does it?
SA-350 LF2 Class 1 material is impact tested to -50 deg F. The average minimum absorbed energy for three test specimens is 15 ft-lb, the minimum absorbed energy is 12 ft-lb (15 avg, 12 min). The minimum yield strength of the material is 36 ksi. Per Fig UG-84.1 The required average impact test requirements rises from 15 to 18 ft-lb because the material is greater than 2 inches thick. The minimum required is 2/3 the average or 12 ft-lb (18 avg, 12 min).
Fig UG-84.1 for SA-350 LF2 Class 1 material
The test requirement from the SA-350 standard is no longer adequate! However, this portion of the code has gone through many revisions and updates which have disguised the intent of the rules and left us only with a mess of code passages to follow. Note c on the bottom of figure UG-84.1 exempts this material from the requirements of figure UG-84.1. So the material tested to the SA-350 standard is acceptable!
We can hope for code rules that make sense, but instead with each revision we get more rules that contradict and confuse. How does your company deal with this tortured mess of requirements? Putting the impact absorbed energy requirements on the drawing is one way to make sure that the code requirements are considered during the design cycle and met during production.
Will I Need to Renew My CRN?
File: 4711
Last Updated: Dec 20/2010
By: LB
Fittings
CRNs for fittings expire after 10 years. If the registration is not renewed, no new pressure vessel or piping designs can be registered that use it however end user will keep using the same fittings and ordering spare parts and replacements for existing systems, even though the CRN is no longer valid.
The CRNs for fittings expire because provincial registration requirements vary vastly with time. Companies currently re-registering fittings (registered before 2003) now have to supply engineering proof that the design is safe whereas before 2003 a statutory declaration, proof of QC program and a catalogue were often sufficient. When fittings currently being registered expire in 10 years the requirements might be different again.
If a fitting is registered in one province one year it will be valid for 10 years. If the same fitting is registered in another province later, it will expire at the 10th anniversary of the registration in the first province, not at the anniversary of the subsequent provinces.
Registrations of fittings shall be resubmitted for validation not more than ten years after the date of acceptance by the regulatory authority in the original registering province. (CSA B51-09 4.2.1)
Pressure Vessels and Boilers
Pressure vessel CRNs do not expire. The manufacturer can make as many copies of the design as they want without re-registering. If the code of design changes like the change from TEMA to UHX on heat exchangers, then the manufacturer will need to re-register the design to continue production. Similarly the change from 1998 to 1999 material strength changes required re-registration if the manufacturer wanted to take advantage of the allowed higher stress levels.
The pressure vessel calculations need to get reviewed yearly to check for compliance to the current code, same as under a National Board registered production.
Any number of boilers, pressure vessels, fittings, fired-heater pressure coils, and piping systems may be constructed from a registered design until a change in the applicable Act, Codes; or Standards invalidates the design, in which case the design shall be obsolete and no further construction to the design shall be made after the effective date of the change as established by the Act. When the Act does not specify an effective date of change, the effective date shall be the date specified in the changed document or six months from the published date of the change, whichever comes first (CSA B51-09 4.1.2)
Piping Systems
Piping systems need to be re-registered for each installation unless it is a duplicate installation at the same address. If you are making multiple copies of skids, see if you can register your piping system as a fitting instead (it will need to be less than 1- 1/2 cuft for the whole piping system). If so, you can avoid having to register each item sold. Many duplicate machines classify as piping systems and need to be registered each time they are sold even though they are identical. Note that B51-09 4.1.2 (quote above) says that the manufacturer can make as many copies of the piping system as they want; the provinces require the piping installation address as part of the registration making this impossible. For example see TSSA) and ABSA.
Using Fittings in Vessels and Piping
File: n/a
Last Updated: Dec 13/2010
By: LB
Under the B51 program fittings need to be registered before they can be used on pressure devices. However, fittings on pressure vessels are exempted from requiring registration by B51-09 clause 4.2.1:
Fittings shall be registered in accordance with Clauses 4.2.2 to 4.2.9 unless they form a part of a boiler or pressure vessel that is subject to inspection by an authorized inspection agency. Registrations of fittings shall be resubmitted for validation not more than ten years after the date of acceptance by the regulatory authority in the original registering province or by a nationally recognized organization as specified in Clause 4.2.3.
In practice, all fittings on pressure vessels need to be registered except those listed in VIII-1 UG-44:
UG-44(a) ASME BI6.5, Pipe Flanges and Flanged Fittings [see UG-ll(a)(2)]
UG-44(b) ASME B 16.9, Factory-Made Wrought Butt welding Fittings
UG-44(c) ASME BI6.1l, Forged Fittings, Socket Welding and Threaded
UG-44(d) ASME B16.l5, Cast Bronze Threaded Fittings, Classes 125 and 250
UG-44(e) ASME BI6.20, Metallic Gaskets for Pipe Flanges - Ring-Joint, Spiral-Wound, and Jacketed
UG-44(f) ASME B 16.24, Cast Copper Alloy Pipe Flanges and Flanged Fittings, Class 150, 300, 400, 600, 900, 1500, and 2500
UG-44( g) ASME B 16.42, Ductile Iron Pipe Flanges and Flanged Fittings, Class 150 and 300
UG-44(h) ASME BI6.47, Large Diameter Steel Flanges, NPS 26 Through NPS 60
All other fittings will need registering. This exemption is applied to both ASME "U" vessels which are inspected by an authorized inspector and "UM" vessels which are not inspected by an authorized inspector. This exemption also applies to fittings which include any of the above.
In contrast B51-09 clause 8.2 demands the registration of fittings on piping systems:
Fittings used in piping systems shall be registered in accordance with Clause 4.2.
So these same fittings that are exempt on vessels which might be inspected by an authorized inspector are never exempt on piping systems that are always inspected by an authorized inspector. This made no sense to us so we made up a diagram to help illustrate:
The red items need registration*, the green items do not. Sense or nonsense, these are the rules as they are currently written and applied in Canada.
* Many of these fittings do not need to be registered for use in Saskatchewan or British Columbia (more here: Fittings).
Registering B16.9 Fittings
File: n/a
Last Updated: Dec 13/2010
By: LB
B16.9 fittings (elbows, tees, crosses, reducers, caps and stub ends) must be CRN registered before they can be used in Canadian CRN registered piping systems*. The 2009 B51 standard introduced a simplified approach to registering fittings found in table UG44 of the VIII-1 code book. B16.9 Fittings are one of these components in table UG-44:
At a minimum, the following documentation in support of an application for a new design registration or a reregistration shall be required: (a) for new applications for fittings that are built to a nationally recognized Standard (e.g., as listed in paragraph UG44, Section VIII, Division I, of the ASME Code or Table 326.1 of ASME B31.3) that specifies the dimensions, construction, materials, pressure/temperature ratings, and identification markings of the fittings (B51-09 4.2.6(a))
These components have a simplified registration process requiring only 3 items:
- a properly completed statutory declaration form for the registration of fittings clearly identifying the applicable nationally recognized Standard; -
- the manufacturer's scope within the Standard; and
- the manufacturer's identification marking(s). (B51-09 4.2.6(a))
This would work for B16.5 flanges where the dimensions, materials and pressure temperature rating are fully specified by the B16.5 code. Likewise other fittings listed in UG-44 are also fully specified by the design standard so there is nothing for the manufacturer to design. The problem is that ASME Standard B16.9 does not specify wall thicknesses, so this simplified registration process cannot be applied.
The design of fittings shall be established by mathematical analyses (e.g. ASME B16.49 for bends) contained in nationally recognized pressure vessel or piping codes or at the manufacturer's option by proof testing in accordance with section 9 of this Standard. In order to meet design or manufacturing requirements, it is expected that some portion of formed fittings may have to be thicker than the pipe wall with which the fittings is intended to be used. The mathematical analyses, if used, may take into account such thicker sections. Records of mathematical analysis and/or successful proof test data shall be available at the manufacturer's facility for inspection by the purchaser. (B16.9-2001 Section 2.2 "Design of Fittings")
The user of a B16.9 fitting calculates its pressure rating as an equivalent piece of straight pipe. The manufacturer of the fitting has to provide proof that the fitting is the same strength as that straight pipe. A longer registration process is required:
- a properly completed statutory declaration form for the registration of fittings;
- the designation of the Code or Standard;
- material specifications;
- identification markings;
- dimensions; and
- detailed calculations and/or copies of proof test results witnessed by an inspector or an authorized inspector and acceptable to the regulatory authority
(B51-09 4.2.6(b))
Once the manufacturer provides this proof, along with other provincially required paperwork to each jurisdiction and gets the registration back, then the B16.9 fittings can be used in registered Canadian piping systems.
*B16.9 fittings do not need to be registered for use in Saskatchewan or British Columbia (more here: Fittings).
We Don't (Usually) Register Actuators
File:PVE-4711
Last Updated: Dec 3/2010
By: LB
We often get asked to register valve actuators, but usually we don't do it for a couple of reasons...
Practical:
It is not possible to get many actuator designs to pass the ASME code rules which would be required for registration. For starters, picture this actuator being redesigned to use B16.5 flanges instead of its stamped steel flanges integrated into the housing. Not that there is anything wrong with this type of design, it just is not the way we usually design code pressure parts.
There is a class of actuator that has the piping system pressure on one side of the diaphragm. These actuators do need to be registered, which means that the actuators need to pass code rules.
Some valves have built in regulators where the housing for the regulator is the same part as the valve body. The stresses from the regulator need to be included with the stresses from the valve when the this type of valve is analyzed.
ASME VIII-1 - the bible of pressure vessel design - states this about the design of actuators:
U-l(c)(2) Based on the Committee's consideration, the following classes of vessels are not included in the scope of this Division; however, any pressure vessel [or actuator] which meets all the applicable requirements of this Division may be stamped with the Code U Symbol:
U-l(c)(2)(c) pressure containers which are integral parts or components of rotating or reciprocating mechanical devices, such as pumps, compressors, turbines, generators, engines, and hydraulic or pneumatic cylinders where the primary design considerations and/or stresses are derived from the functional requirements of the device;
Or to paraphrase ASME - you can use pressure vessel rules to design valve actuators if you want, but because the primary loading is from the force on the valve stem, the use of only code rules in the design of actuators will probably not be adequate.
CRN Rules:
The actuator on a valve is not part of the piping system for the fluid that the valve is regulating. It is part of the instrumentation piping system. These piping systems are usually small diameter and contain air. Each province has its own piping rules, but most do not require registration of small diameter air piping systems. For example in Ontario any air line 3/4" diameter or less does not need registering. (See piping charts for all provinces here ). An actuator is a fitting attached to a line and a fitting does not need registration if the line that feeds it does not need registration. Similar exemptions usually can be found for hydraulic actuators.
Exceptions:
There will always be exceptions, occasionally your actuator will need registering, but most of the time it will not. Also, the valve might still need registering even if the actuator does not.
Code Updates
File:PVE-4711
Last Updated: Nov 17/2010
By: LB
It's that time of year again. The weather is getting colder, Christmas displays are in the stores and pressure vessel engineers are thinking about code updates.
Under National Board registration, a manufacturer will create a production drawing and state "latest code and addenda" under the code conditions block. A calculation set will be made to the current code and addenda. Copies of the vessel can be manufactured for the rest of the calendar year. After the year end rolls around one of two things happens. Either the code calculations are re-run (easy to do with commercial software) or the calculation set is reviewed and signed off that no code changes affect the calculation set. Production continues for another year. The drawing does not get updated until a code update forces a design change or some manufacturing detail changes.
Those familiar with the CRN system will realize that we crazy Canadians have succeeded in making this simple process more difficult and more expensive. In Canada we do not allow the words "latest code and addenda" on pressure vessel drawings when they are being registered. When the vessel is submitted for CRN registration, the drawing states an actual year and addenda. The calculation set is also done to the same year and addenda. After getting a CRN, non-Canadian manufacturer often revise the drawing set to show "latest code and addenda" so that the drawing does not need to be unnecessarily updated every year.
If the vessel is registered in one province in one year, and then the manufacturer wants to register it in another province in a later year, then the calculation set needs to be updated. The drawing no longer matches the calculation set so it needs to be updated. The updated calculation no longer matches the one registered with the first jurisdiction. Two choices are available: 1) update the registration with the first province, then register in the second - the CRN number is the same in both provinces - or - 2) Get a new CRN number in the second province. The vessel will end up with two CRN numbers. This becomes a nightmare if the vessel ends up in a province that does not match the CRN number on its nameplate (think shipping a vessel to a customer in one province who puts it on a skid and ships it on to a different province).
I have been told that the jurisdictions have been trying for years to work around this unnecessary and expensive complexity. For now we wait.
Comments on AB-520
File:PVE-4711
Last Updated: Jan 3/2010
By: LB
We came across ABSA AB-520 the usual way. We submitted a job with a bunch of FEA reports and were told that ABSA now had an FEA guideline and we would have to re-do and re-submit our work. Unlike other times our work was rejected for undocumented reasons, this time was different... the guideline was in writing. AB-520 started its first couple of years as an anonymous document. It was quickly adopted by other provinces as an unofficial guide to how to do FEA. A couple of years later it was reformatted a bit and officially released as AB-520.
Because of the way it was introduced to us, we did not like it at first. We did however learn to work with it and the difference can be seen in our reports. We accept that this is an improvement in how FEA reports are done, but AB-520 still leads to confusion when we submit reports for ABSA review. One example, the article states:
The following figures must be presented (coloured prints):
4) Plot with element stress and compare nodal (average) stress vs. element (non-averaged) stress (If the small difference is less than 5%, the accuracy should be OK);
We have always taken this to mean that we should show an error plot and the error should be less than 5%. This is good and easy to include in the report. What the article does not mention is that in areas of surface contact reported errors will be above 5%. Sharp corners have theoretically infinite errors. We often explain this, and point ABSA reviewers to our articles on this effect. (More information on this topic can be found
here
hereand
here.
This standard is written by reviewers to make the review process easier which is very important. However, it is not written by FEA users who know what can and can not be done. If we knew that the original release was going to be revised and officially released later we would have liked to made a few suggestions. There is still time to make changes before it gets added to a national standard like CSA-B51 and improvement becomes impossible.
This guide would be better if it did what ASME does in some of the better areas of the pressure vessel code - include an example of what is considered to be good work or good method. Under current practice ABSA reviewers are asking for many incremental re-writes of reports. Samples of good working practice could reduce this.
As a postscript, AB-520 now has a partner. ACI has produced their own FEA guideline that is completely different from AB-520. We are now in the process of re-writing reports done to AB-520 to meet the ACI guidelines. Although we have confidence that we can create reports that can harmonizing the two standards, this requires more flexibility from review engineers than is sometimes given. Let's hope no other provinces come up with additional FEA guidelines in the future.
National Board Vessels in Saskatchewan
File:PVE-4711
Last Updated: Jan. 27, 2012
By: LB
The previous post discussed that Saskatchewan now accepts National Board as the registration method for vessels for use in Canada if the following conditions are met:
1. The boiler or pressure vessel:
a. is constructed in strict compliance with the administrative and technical rules of the appropriate section of the ASME code;
b. is stamped in accordance with the ASME code with the applicable code symbol stamp;
c. is registered with the National Board of Boiler and Pressure Vessel Inspectors (NBBI);
d. records the NBBI registration number on the data report required by the ASME code;
e. and stamps the NBBI registration number on the nameplate of the boiler or pressure vessel.
To use this registration option as an alternative to the CRN process:
Before a boiler or pressure vessel mentioned above is installed, the owner must submit the data report for registration. The fee for the registration of the data report is $110.00 and shall accompany the data report.
Technical Safety Authority of Saskatchewan
330-1855 Victoria Avenue
REGINA SK S4P 3T2
Make check payable to: Technical Safety Authority of Saskatchewan
For more information on National Board registration in Saskatchewan scroll down to "Exemptions from Registration Requirements" for New Designs and Other Registrations.
We are PVEng are grateful that Saskatchewan has put the effort into making this alternative to the CRN process available and wish other provinces joined in!
A New Hope?
File: File:PVE-4703
Last Updated: Nov 11/2010
By: LB
Clearly Canada's use of the "CRN" registration system makes us much different from other countries, and keeps many products out of use in Canada. However in the last 10 years, in the face of massive increases in the difficulty of registering pressure products in Canada, two positive changes have happened: 1) Saskatchewan is now accepting the use of products registered under the international standard National Board system. And 2) Both BC and Saskatchewan have reduced the number of categories of fittings that they see as being necessary to register.
Saskatchewan's updated their adoption act to allow both National Board registered vessels, and vessels registered in other provinces to be used in Saskatchewan. This is the first progress in inter-provinical trade in pressure vessels in many years. First, the changes to the Saskatchewan act. The following are now considered to be legal in Saskatchewan:
The boiler or pressure vessel: is constructed in strict compliance with the administrative and technical rules of the appropriate section of the ASME code; is stamped in accordance with the ASME code with the applicable code symbol stamp; is registered with the National Board of Boiler and Pressure Vessel Inspectors (NBBI); records the NBBI registration number on the data report required by the ASME code; and stamps the NBBIregistration number on the nameplate of the boiler or pressure vessel. - OR -
The boiler or pressure vessel: is constructed in a province or territory of Canada other than Saskatchewan in strict compliance with the administrative and technical rules of the appropriate section of the CSA B51 code; is assigned a Canadian Registration Number (CRN) by the boiler and pressure vessel authority of the province or territory in which it is constructed; is inspected during construction by an inspector employed by the boiler and pressure vessel authority of the province in which it is constructed; records the CRN on the data report required by the CSA B51 code; and stamps the CRN on the nameplate of the boiler or pressure vessel
The second change is that both BC and Saskatchewan no longer require registration of category A, B, C and G fittings, see the chart below for the categories (More Info)
Good news is nice for a change!
Code Cases and Interpretations in Alberta
File:PVE-4340
Last Updated: Oct 6 2010
By: LB
 Code Cases in Alberta |
|
Alberta does not automatically accept either ASME code cases or Interpretations. See Alberta document AB-51 page 23:
Interpretations and code cases are not part of the code, and are
not automatically adopted for use in Alberta. Use of
interpretations and code cases may be accepted on an individual
basis upon application to ABSA. Check with ABSA Design Survey
before attempting to apply interpretations or code cases.
For example code case 2596/cold stretched vessels is not accepted in Alberta.
Interpretations for ASME VIII-1 can be found at
cstools VIII-1 (2007)
ASME VIII-2 Interpretations can be found at
cstools VIII-2 (2007)
and VIII-3 at
cstools VIII-3 (2007).
|
Miniature Vessels in Alberta
File:PVE-3854
Last Updated: March 25/11
By: LB
"The Pressure News" published by ABSA has a write up on registering miniature pressure vessels for use in Alberta (Volume 13, Issue 22, June 2008, Page 4). Alberta no longer allows vessels small enough to be classified as fittings to be registered if they are not designed and built in accordance with ASME VIII-1. Under some circumstances the shop inspection will also have to be done by an Authorized Inspector. Each jurisdiction sets the rules for the products under their control. ABSA has set a rule for small vessels in Alberta and put it in writing. Conform and your products can be used.
This is an age old trade-off. What level of restriction do we place on free trade to achieve our safety standards? Do we allow a wide range of products into Canada, and accept the standards that they are built under, or do we restrict ourselves to using a smaller selection of products that meet our local standards? Alberta is the only jurisdiction to insist on VIII-1 for miniature vessels. We have never had a fitting rejected for this reason anywhere else in Canada, and could register them in Alberta this way until the summer of 2010. Further, it was another jurisdiction that taught us to register miniature vessels with unlisted materials this way.
The primary motivation for not using VIII-1 to register miniature vessels is to allow the use of non-code listed materials. Typically piping codes like ASME B31.3 are used which provide methods of adopting unlisted materials. It is a reality that many miniature vessels are made around the world out of non ASME listed materials. This is often done for pulsation dampers as shown in the picture.
See also the burst testing problems page for another issue that treating fittings as small vessels raises.
This is a major change for Alberta, and the rest of Canada if any other provinces go along. Some fittings can be registered across Canada except Alberta. The manufacturer has a choice to make, redesign the product to get access to the Alberta market, or accept registration for the rest of Canada without the re-design. Alternately, two products can be used - a custom product for Alberta and the standard part for the rest of Canada, registered under separate CRN#s.
Update Oct 2011: As of this year ABSA is still occasionally advising some manufacturers to use B31.3 to design miniature vessels for use in Alberta for limited applications. We suggest contacting ABSA to get permission in writing before attempting to use B31.3 on your miniature vessel destined for Alberta.
Possible Crazy Future CRN Directions
File:PVE-3854
Last Updated: Aug 20/10
By: PVE
 Duplicate Registration of A Fitting |
|
We have had 2 jobs where fittings that carried current CRNs were refused by two jurisdictions because the Code of construction of the piping system did not match the code used to calculate the fittings. In one case we had to change the design code of the piping system to match the fittings. In the other case we had to re-register the fittings to match the piping system. The piping system was put on hold until the fittings duplicate CRNs were complete. Although this has only happened to us twice we have experienced many CRN requirements that initially seem unnecessary but end up becoming standard practice. (Our files PVE-2736 and PVE-3786.) |
