Hermetically Sealed Level Switch, Div 2 area

[nhee2]

Is there a specific listing or labelling required for 'hermetically sealed' devices in Class I, Div 2 areas?

I have to monitor for leak/level in a Class I, Division 2 location. 501.105(B)(2) exception 2 allows for general purpose enclosures if contacts are hermetically sealed. A dwyer F6-SS such as shown at https://www.dwyer-inst.com/PDF_files/E_100_F6_rev4.pdf is described as hermetically sealed. I think installing this switch (without any additional I.S. barriers) meets 501.105(B) requirements, but am checking to see if I am missing something.

I understand I would still need a boundary seal at the Div 2/non-hazardous boundary.

Thanks

 

[rbalex]

I would want to see a NRTL mark. It wouldn't necessarily say the device was hermetically sealed, simply that it was suitable for Class I, Division 2.

 

[nhee2]

I would want to see a NRTL mark. It wouldn't necessarily say the device was hermetically sealed, simply that it was suitable for Class I, Division 2.

Thanks, I think I saw you provide this answer or similar in some old post responses as well.

Is that a design preference or do you see that as a code requirement? I ask because the exceptions in 501.105(B)(2) read as ….one of..... and list either hermetically sealed or listed for Div 2. (2017 edition).