API 500 part 6.5 interpretation?

[burtonwr]

Looking for some clarification on part 6.5 of API RP 500, specifically around subpart e. Subpart e states that when gas detection sniffs 40% LFL, power must be cut from all electrical devices that are not suitable for Div 2. The way i'm interpreting this is that i can have an inadequately vented area with unclassified components as long as i have gas detection that trips all power non-div 2 components on a 40% detection, and call the whole area Div 2?!

The situation that i'm trying to address is an inadequately ventilated area that processes produced water. With any process upsets, the produced water is likely to contain condensate carryover, thus i'm classifing the area as div 1 as described in 10.8.1.1.2.3.
Though I imagine adequate ventilation is the preffered fix, we're operating in very cold temperatures, so freezing is an issue.

Any advice or help on this would be great! -Thanks

 

[dcasto]

Is the tank and and its vents inside too? If not, the pumps and the building around them would be div 2.

 

[chicopee]

If you have a classified area, then all electrical components must be suitable for that area regardless of ventilation. Also check out the Electrical Code NFPA#70 for classified areas.