Change to area classification.

[Markmy]

Does addition of a natural gas line in the process area change the area classification from non-classified to Class 1 hazardous?

 

[rbalex]

Not necessarily. See Section 500.5(B)(2) IN No.2. : Piping without valves, checks, meters, and similar devices would not ordinarily introduce a hazardous condition even if used for flammable liquids or gases.

The converse is not necessarily true; I.e.,Piping with valves, checks, meters, and similar devices will not necessarily create a classified location either - but the analysis is far more stringent.

 

[Markmy]

.Thank you for pointing to the NEC. Yes, I believe that even in case of bad pipe leak, the concentration of flamable gases in the air is in insufficient quantity to become explosive or ignitable.
Thank you again for your detailed response.