Insulating hot surfaces in Zone 2 electrical area classifications

[Bangrod]

Does anyone know the standard industry practices at refinery or similar industrial process plant that has hot pipes, flanges, valves, etc. that are installed in an IEC Ex hazardous locatioin area rated as Zone 2, IIB+H2 and requiring a T3 temperature code when many of the process piping components are expected to exceed 200 C exposed surface temperature?

Will ALL surfaces >200C be insulated somehow? Or are there some exceptions for surfaces that inherently operate at hot temperatures do to the process temperatures of the equipment involved?

Thanks,

 

[ATEXConsultant]

Hi,

If the temperature class requirement is T3, you just can't have any surface exceeding 200 deg C. They might be some exception but that would require proper testing to see if the surface is ignition capable.
Regardless, I certainly would not recommend to have any surface exceeding 200 deg C.

If there is an ignition source, like the mention surface then a suitable protection concept should be applied, or the process might need to be re-design to prevent such surface from occurring.

I hope this helps

Vincent P.

 

[Bangrod]

Vincent,
Thanks for the reply.

Do you know what standards would apply for determining/testing whether or not the surface was ignition capable?

Do you know of any standards that define the specific requirements for insulated pipe / components in the classified area? For instance, does the insulation need to be closed cell, or appropriately shrouded so that minimal air/gas mixture can permeate the insulation and reach the hot surface?

Thanks

 

[ATEXConsultant]

Hi Bangrod,

In Europe I suggest that you look at the list provided at

http://ec.europa.eu/enterprise/poli...s/equipment-explosive-atmosphere/index_en.htm

for IEC Ex certification, the IECEx website.

For mechanical equipment I would look at the 13463 series of standards, for electrical 60079. Starting with an ignition hazard assessment to EN 1127-1:2011.

The exact choice of standard would require the precise review of the equipment and ATEX category.

If you want to discuss further, please, contact me via linkedin, my profile is at:

http://linkd.in/ExConsult

Kind regards - Vincent P.