PVC Conduit in a Class 1 area 1

[ballenEEUK]

Hello, one of our clients use Gas chromatographs, while installing one the manufacturer instructed us to us PVC schedule 80 4" as a sheath over the gas sampling line between the gas supply line and chromatagraph. Since we are not sending power through the conduit, except heat tracing, can we use PVC in a Class 1 Div2 area? Thanks.

 

[roydm]

Yes, in US and Canada anyway but if it enters a non hazardous enclosure you should still have a seal to prevent migration of explosive vapour
Roy

 

[ballenEEUK]

Ok thanks. I just wasn't sure if NEC 500 would prevent us from using it, since it is in a classified area.

 

[itsmoked]

"Not power except heat tracing"...

That's like 'sort of pregnant'.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[roydm]

Good catch Keith, a star for you my son! I missed that. I guess if the tracing is approved it should be OK, I would be more worried about the PVC sagging due to the heat from trace. Perhaps a metal duct or pipe would be more applicable.
Roy

 

[ballenEEUK]

OK thanks guys, unforntunately this had already been installed, I have had a converstion with project manager about why it was a code issue and it will be corrected using either a open raceway or metalic flex conduit.

 

[RyanJackson]

Please note the following change in the 2008 NEC, which may help:

501.10(B)(7) In industrial establishments with restricted public access where the conditions of maintenance and supervision ensure that only qualified persons service the installation and where metallic conduit does not provide sufficient corrosion resistance, reinforced thermosetting resin conduit (RTRC), factory elbows, and associated fittings, all marked with the suffix -XW, and Schedule 80 PVC conduit, factory elbows, and associated fittings shall be permitted.