Locknut on cable compression gland in hazardous area

[ICLL]

Can anyone advise if it is considered essential to fit a locknut to the inside of a compression gland for a steel-wire armoured cable entering a threaded cable entry in an ex'e' enclosure in a Zone 2 hazardous area?

I can understand that the locknut would be essential to maintain earth continuity of the cable armour if the enclosure entry was not threaded (e.g. a punched hole in a glandplate). In fact the gland could fall right out if there was no locknut.

But in a threaded entry, what purpose does the locknut serve? The fastening tension and earth continuity is between the gland and the entry thread. The locknut seems like a nice to have. Does it really add some security? Would the assembly fail a hazardous area inspection without the locknut?

IEC regulations in an Australian oil and gas application.

 

[waross]

With Canadian hardware it may depend on the threads. With tapered pipe threads there would not be a need for a locknut. If the hardware has non-tapered threads a locknut may be a good idea, but I would not expect to see straight threads on our Ex hardware.

Bill
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