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The ASME Codes for Pressure Vessel Design are utilized for pressurized equipment, such as vessels, piping, and fittings, in various regions around the world, including North America. These codes encompass the design, construction, maintenance, and modification of pressurized equipment. The commonly used ASME codes include:


  • VIII-1 for vessels, towers, and exchangers
  • I and IV for hot water heaters and boilers
  • B31.1, B31.3, and B31.5 for piping systems
  • B31.3 is often applied to various fittings

These codes rely on rule-based design and offer formulaic approaches that are effective when the design is within the limits of the code's scope.

The qualified welding procedure is owned by the company and not the welder who conducted the qualification tests. Therefore, departure of the welder will not affect the status of the qualified welding procedure and no requalifications are required.
A pressure vessel, fitting or piping that contains liquids not more hazardous than water and that operate at a temperature of 150°F (65°C) or less and at a maximum allowable working pressure of 250 psi (1,717 kPa) or less is exempt from TSSA boiler and pressure vessel regulations.
Professional inspections of boilers should occur on an annual basis, although there are various types of inspections that an inspector can conduct. To ensure safety and compliance, regulatory bodies and insurance companies typically advise that power boilers undergo both internal and external inspections annually, while they are not pressurized. Additionally, an external inspection of the boiler while it is under pressure is recommended halfway between the annual inspections.
If the computations do not require any changes, then the likelihood is that re-registration won't be necessary. For instance, if you're adding a nozzle that's similar to an existing one on the vessel and not positioned too near another nozzle, you probably don't need to register it again. However, you should get in touch with an authorized inspector in your area. It's crucial to note that only companies with a valid QC certificate, such as an ASME "R" stamp, should undertake the work.
If the calculations and drawings are available and the code of construction meets the acceptable standards, it may be worth considering. However, if non-ASME codes and materials are utilized, it is typically not worth the effort.
Yes, to proceed, you will need to provide the original drawings and calculations, or recreate them if they are not available. Specific requirements may differ, but typically, the calculations must be redone using the stress allowances from the original construction year and the latest code regulations. Additionally, you will need to include a picture of the nameplate and the manufacturer's data report. Keep in mind that used vessels will typically require an inspection, such as ultrasonic testing, to confirm that the vessel is still suitable.
With the exception of Saskatchewan, all provinces permit it. The registration encompasses the design and assigns it to an owner. An approved inspector will verify that sufficient QC measures and appropriate quality control procedures are implemented during the construction process. It is important to note that this assumes that all manufacturers are legally authorized by the design owner to build the vessel.
In Canada, numerous fittings, piping systems, and pressure vessels that require CRN were not previously registered and are frequently discovered during inspections by authorized inspectors or insurance audits. If one of these unregistered products is detected while in use, it must be registered, or if it cannot be registered, it must be replaced. In the event of safety concerns, the product must be shut off until it is registered or replaced.
The validity of the CRN attached to a vessel extends throughout the vessel's lifespan. As for a manufacturer, the CRN can be utilized until either the design needs to be altered due to code modifications or until design alterations are deemed necessary.

It is necessary to apply for the CRN prior to commencing construction, as stated in B51 which mandates that "Acceptance and registration shall be obtained before construction is commenced." This could pose a challenge for a manufacturer who has a finished vessel and is informed on the shipping date that the vessel is destined for Canada. However, it's important to note that this requirement may differ depending on the jurisdiction. For instance, the Ontario vessel act offers an alternative where a person can commence construction of the boiler, pressure vessel, fitting, or piping before the submission is registered if they assume all the risks related to the construction for an installation or alteration. It is advisable to allow ample time for registration to avoid complications.

Registration and issuance of a CRN number for boilers and pressure vessels are handled independently by each province. However, the Atlantic Canada provinces and northern territories have formed a partnership and established a centralized registration organization called ACI Central. To register a vessel in all 13 provinces and territories of Canada, you need to comply with the registration requirements of seven different organizations or jurisdictions.