CRN for Pressure Fittings in Canada

Reviewed by CRN expert team · Last updated: October 4, 2026

Pressure fittings (valves, flanges, strainers, expansion joints, couplings, manifolds, and pressure relief devices) require individual CRN registration under CSA B51. Fittings are registered in categories A through H, each covering a different component type.

CSA B51 Fitting Categories A-H

• Category A: Pressure relief devices (safety valves, relief valves)
• Category B: Fittings with pressure-containing parts (valves, check valves)
• Category C: Bolted flange connections
• Category D: Flexible connections (expansion joints, hoses)
• Category E: Instrumentation fittings
• Category F: Pressure-containing specialty items
• Category G: Welded fittings (elbows, tees, reducers)
• Category H: Threaded fittings

The category letter assigned to a fitting determines the shape of its application. Each category covers a different component type, so the first step in a fitting registration is matching the product to its category and confirming that match against the category definitions.

Statutory Declaration: Unique to Fitting CRN

Fitting CRN applications require a Statutory Declaration: a legal document signed by a company officer and notarized before a Commissioner of Oaths. The declaration attests that all fittings produced under the CRN will be identical to the approved prototype.

The declaration links registration to production discipline. Because it attests that every fitting produced under the CRN will be identical to the approved prototype, the registered design becomes the fixed reference for production.

Family Registration Strategy

OEMs with large product lines benefit from family registrations covering multiple sizes and pressure ratings under one CRN. Kopfkino structures valve family registrations that minimize total CRN count while maximizing product coverage.

A family registration is defined by its boundaries. The submission states the range of sizes and pressure ratings the CRN will cover, and the governing design and burst-test evidence are chosen to represent that range. Sizes within the defined parameters are then covered by the one registration.

Frequently Asked Questions

Do I need a separate CRN for each fitting size?

Not necessarily. A well-structured family registration can cover multiple sizes within defined parameters.

"Fittings are where CRN strategy pays for itself. A well-structured family registration can cover dozens of SKUs under one number, but only if the governing design and burst-test evidence are chosen correctly up front."