CRN : Canadian Registration Number

SMC products, such as pressure vessels, piping systems and the fittings used in Canada are subject to the CRN system. Cylinders are out of the scope.
The CRN system is governed by the general CSA B51 standard, but CRN registration is required for each Canadian province and territory where the equipment is used, since every jurisdiction adds their own specific rules and exemptions.
SMC has registered CRNs according to each jurisdiction.

Refer to the CRN on the SMC US website.