confined spaces-lighting

[rburns001]

We have been using 24v.d.c., cord and plug, explosion proof, incondescent lighting inside vessels when doing work during a shut down. We have been doing this for many years and I have never seen this practice in writing or anything specific in writing about having to have 24v. lighting or to have all cord connections outside of the vessels.
My question is: Is there a requirement,(osha, nfpa, or nec), that states what kind of lighting is to be used, what voltage is be used, and about making cord plug connections outside of vessel?
The vessel entry in question is a methenol storage vessel. The vessel has been emptied, cleaned, and tested for with the LEL and CO meter. Atmosphere is o.k. and personnel have LEL monitors. A 120v.a.c. quartz light was put in the enclosed vessel. A 6' cord with a 120v woodhead plug was plugged into an extension cord. The extension cord went outside of vessel and into a gfci receptacle which was plugged into a generator. I say that the light should not plug up inside of the vessel.

 

[mclain]

Re: confined spaces-lighting

If the vessel has been cleaned and tested as being safe I don?t see any problem plugging the light in inside the vessel. The quartz light you are using if not certified for hazardous areas would be more of a danger that the plug. I worked in a shipyard were vessels were brought in and cleaned and welding was done inside to modify the vessels. This was an everyday occurrence. We installed incandescent work light with fully in closed lamps and non-certified blowers to keep the vessels vented. The cleaning area was separated from the rest of the shipyard and all wiring in the cleaning area was done to class 1 division 1 requirements. This was years ago and it is possible that the rules have changed since then.

Don McLain

 

[rburns001]

Re: confined spaces-lighting

This is a good point about the welding that is done inside the tanks. That has been done in the past but I did not get to see the details before or during. The valves leading in and out are closed, locked out and blinded. It is safe. It has been my understanding that we still use precautions because there is still a minute posibility of gasses that could enter under failed safety measures. Were we doing this for extra precaution only or is this mandated by NFPA or OSHA. The reason I ask is the procedures at this plant is different than I am used to and if this is mandated or required we should put it in our procedure.