2005 NEC 250.100 1

[stookeyfpe]

In advance of posting my question I want to thank all of who comment.

Here is the scenario: A fairly large industrial spray booth that complies with NFPA 33 and the 2006 International Fire Code. An airless spraying system is used which uses relatively high pressure hydraulic pumps to transport the flammable liquids from a remote area into the spray booth via a piping system. The piping is bonded to the spray booth which is grounded. The interior of the spray booth is classified as a Class I, Division 1, Group D atmosphere.

When I read Section 250.100 it contains the phrase Regardless of the voltage of the electrical system, the electrical continuity of non-current-carrying metal parts of equipment, raceways, and other enclosures in any hazardous (classified) location as defined in Article 500 shall be ensureed by any of the methods in 250.92(B(2) through (B)(4) that are approved for the wiring method.

Question 1: Is the process piping that conveys a Class I flammable liquid and is located the hazardous location within the scope of Section 250.100 and does the piping need to be bonded to ground?

Question 2: If one was to install an electric solenoid valve in the hazardous location, would a bonding jumper be required between the connection of the pipe to the valve? The valve would be listed for hazardous locations and since its energized, Article 250 requires it also be grounded.

Thanks for your help.

 

[davidbeach]

1. Yes, if metal. If joints may not be conductive all pipe sections would require bonding.

2. Maybe, installation instructions should provide guidance. Depends on electrical continuity of the joints and couplings.

 

[stookeyfpe]

Thanks David. You confirmed my thoughts. I've seen your postings in the NFPA portion of this site and I appreciate the precision of your responses.

The client won't be happy but I'll sleep. Thank you.