electrical area classification for natural gas pipe

[antigfk]

Our local natural gas utility company has recently installed a metering station and a pipe 4" in diameter and the pressure regulator is set to 5psig. We are supposed to hook up a flexible pipe from the utility pipe to our natural gas generator. My gut says this meets the NEC definition of Class I Div II Group D, in that sufficient quantities of gas may be present to create a combustible or explosive mixture. Our safety department is arguing that since it is at low pressure, 5psig, that it does not need to be classified as Class I Div II at all the flanges and metering instrumentation. Am I right in that this area should be considered classified?

 

[Thealanator]

I believe a few residences have blown up because someone operated a light switch after natural gas leaked into the house. Typical entrance pressure at a residence is , say, 4 inches water column.

Your gut is right. I recommend classifying the area.