October 26, 2020 – The 2018 version of CE Code-Part II introduced a new product rating (and related marking) for liquidtight conduits—Heavy Duty (HD)—which is now required for use in any hazardous location that allows the use of liquidtight flexible metal conduit.

(This requirement did not exist in previous versions of CE Code-Part II, where any CSA-approved liquidtight was permitted.)

This new product approval is supported by CSA C22.2 No. 56-17, which spells out the additional testing required to achieve the Heavy Duty rating, and related marking requirement.

HD-rated liquidtight flexible metal conduits boast increased crush resistance and can withstand higher pull-out forces. They are permitted in Zones 2, 21 and 22 per CE Code Section 18, and Class I, Division 2, Class II, Division 1 & 2 per Appendix J.

Now that conduit manufacturers have product approved to this standard, electrical inspectors will be looking for the “Heavy Duty” or “HD” marking on the jacket.

Distributors and contractors will need to be clear when specifying liquidtight conduit, as there are now two (2) grades available:

Regular CSA-approved liquidtight conduit remains the primary solution for applications outside of hazardous locations. When dealing with hazloc installations, check that the Zone allows for the use of HD liquidtight, and is marked accordingly.

(The CSA standard covering liquidtight fittings, C22.2 No. 18.3, has also been recently updated to include requirements for Heavy Duty fittings, and those manufacturers are working on getting their fittings approved.)

John Richardson is vice-president, Sales, with Anamet Canada. He can be reached at jrichardson@anametcanada.com.

This column—along with other great content—appears in the October 2020 edition of Electrical Business Magazine.