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Costing for Class I or Class II Area

Costing for Class I or Class II Area

(OP)
Hi, I'm working on the design of two separate rooms, one is class 1 div 1, the other is class 2 div 2. Right now I'm defining the process aspects (layout, flowrates, PHA, etc), however I need to understand the cost before it gets too far along.

Does anyone know of good references for approximating the room/building cost, especially for a classified area? I've seen some guides/books on general plant costing, but I'm not sure how to add on the cost for meeting nfpa/nec standards. I've heard that controls are usually +40%, and the increase in room cost could be x2 or x3?

Thanks in advance for any help.

RE: Costing for Class I or Class II Area

The construction of the rooms are not any different between Div1 and Div2.

It's the cost of the equipment placed INSIDE those rooms that affect the cost.

So, I'm not aware of any references to costing of room/building costs.

Take a look at electrical enclosure price differences and wiring installation practices between Div 1 and Div 2 areas to get a better estimate.

______________________________________________________________________________
This is normally the space where people post something insightful.

RE: Costing for Class I or Class II Area

Usually Class 1 wiring & devices are very costly, compared to Class 2. Generally one will try to re-classify the Class 1 room down to Class 2 if at all possible. This can be done with mechanical ventilation and gas detection (or heaven's forbid "fugitive emissions" method). Have you considered this?
If you cannot re-classify to Class 2, then try to keep as much of the electrical equipment out of the Class 1 area.
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

RE: Costing for Class I or Class II Area

Get quotes from electrical contractors or you may have to develop a cost analysis by going down to an electrical supply house.

RE: Costing for Class I or Class II Area

Somebody is confused between CLASS and DIVISION or ZONE.

Class 1 means the hazard is flammable gases or vapours.

Class 2 means the hazard is flammable dusts.

DIVISION or ZONE is related to how frequently the hazard is present.

Zones 0 or 1 (Division 1) mean that the hazard is normally or frequently present. Only intrinsically safe or explosion proof equipment/instruments/lighting/wiring methods are permitted.

Division or Zone 2 mean that the hazard is only present occasionally, during an upset such as a leak etc. Nonincendive equipment is permitted, as well as anything suitable for zones 0 or 1 above.

Equipment and wiring for zone/div 2 is cheaper than for zones 0 or 1/div 1, because you have more choice of available equipment/instruments and the wiring methods are less restrictive and take less labour.

There are also temperature classes to be considered, which depend on the lowest igniting mixture that may be present.

CLASS 2 equipment just needs to be certified to be dust-tight/non igniting to dusts, which is obviously a lot easier than making something explosion-proof or nonincendive against liquids or vapours.

RE: Costing for Class I or Class II Area

Howdy Molten;
Sorry, that somebody was me. Good catch.
Perhaps Alphite (the OP) could review his original query wrt Class 1 and Class 2. (ie flammable liquids/gases vs combustible dusts).
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

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