CSA B52:23 Mechanical refrigeration code

Canadian Standards Association (CSA) publishes codes for designing, manufacturing, installing, operating, and maintaining pressure equipment, including CSA B52:23 Mechanical refrigeration code.

Currently, the CSA B52:13 is used in BC. We are proposing to update the PEBPVRSR to use the newest edition, CSA B52:23.

The 2023 edition of the CSA B52 includes new refrigerant classification types, and changes made as a result of learning from recent risks and incidents. Technical Safety BC notified the boiler and pressure vessel industry when CSA held its public review on the CSA B52:23 in June 2023.

Review a read-only version of CSA B52:23 Mechanical refrigeration code on the CSA Communities website (login required – available until March 5, 2024)

The major changes include:

A2L and B2L refrigerant groups

• Introduction of A2L and B2L refrigerant groups. The 2023 edition introduces two new refrigerant groups: A2L (non-toxic, mildly flammable) and B2L (toxic, mildly flammable). Many environmentally friendly refrigerants are in the A2L group. This change aligns with ASHRAE’s refrigerant classifications.
• Installation requirements related to A2L and B2L refrigerants. Installers of refrigeration systems using A2L refrigerants must follow new installation requirements based on the type of refrigerant, occupancy, and leakage probability. Designers, manufacturers, and installers of machinery rooms must follow new installation requirements that are tailored to the specific needs and risks associated with A2L and B2L refrigerant groups. Many of these new requirements are less restrictive than the current applicable requirements, which were designed for A2 and B2 refrigerant groups. This also supports BC’s shift to environmentally friendly refrigerants.
• Design registration no longer required for Canadian-certified refrigeration systems using A1 or A2L refrigerants up to 500 kW.Designers, manufacturers, installers, and owners of refrigeration systems no longer need to register designs for refrigeration systems that meet the following criteria:
  1. certified by a certification body accredited by Standards Council of Canada;
  2. total prime mover nameplate rating up to 500 kW capacity; and
  3. using A1 or A2L refrigerant groups.

Currently, refrigeration systems up to 125 kW capacity do not require design registration. This change promotes using certified refrigeration systems and environmentally friendly refrigerants. The threshold for requiring design registration using all other refrigerant groups is still at the 125 kW capacity mark.

New manufacturing requirements for ammonia refrigerant

• New manufacturing requirements for pressure vessels using ammonia as a refrigerant. CSA B51:24 introduces stricter manufacturing requirements for pressure vessels using ammonia as a refrigerant. This change in CSA B52 clarifies when the new requirements in CSA B51 apply.

New requirements for decommissioning

Requirements relating to safety orders

• Removal of the requirement for an emergency discharge line. New and existing refrigeration systems no longer require an emergency discharge system if their relief piping complies with CSA B52:23. Owners of existing systems with an emergency discharge line must meet the requirements of Safety Order SO-BP 2021-02: Emergency discharge line. This change was based on the recommendations developed after the 2017 Fernie Memorial Arena incident investigation. Designers, installers, and owners in BC are already familiar with these requirements, as Technical Safety BC issued a safety order with similar requirements in 2021. Read Safety Order SO-BP-2021-02: Emergency discharge line for details.
• Design and testing of secondary coolant systems (brine). Installers and owners of refrigeration systems using a secondary coolant must address how the system can safely withstand the effects of a refrigerant leak. The 2023 edition of CSA B52 also introduces additional requirements for secondary coolant testing. The goal of this change is to detect early warning signs of over pressurization and prevent ammonia release and is based on the recommendations developed after the 2017 Fernie Memorial Arena incident investigation. Owners and maintenance contractors in BC are already familiar with this change, as Technical Safety BC issued similar requirements in 2021. Read Safety Order SO-BP 2021-01: Secondary Coolant Systems for details.

Air conditioning systems in private residences

New mandatory annexes

Read more about the 2023 edition on the CSA website

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