[labnetwork] duct material for pyrophorics

[Bill Flounders]

Iulian,
For Lab/Process Exhaust Duct:
It is unlikely you will have an exhaust stream that is only pyrophoric gas.
Pyrophoric and corrosive gases are commonly exhausted from the same tools.
The coatings are for corrosion resistance.
Epoxy coating  (common product names - plasite or tnemec)
on galvanized duct work or teflon coating on SS ductwork
are common. The teflon coated SS is expensive and not possible
to field retrofit. It is beautiful and considered the Cadillac soultion.
The epoxy / galvanized solution is more affordable, ducts
can be modified in place and epoxy coatings manually painted on
any exposed surfaces.
If you have a pyrophoric initiated duct fire - the main fuel source
of concern is accumulated pump oil - not the corrosion resistant
duct coatings.

For dedicated Gas Cabinet or VMB Exhaust Duct:
coating is not required

Bill Flounders
UC Berkeley


Iulian Codreanu wrote:
> Good Afternoon Fab Network.
>
> Is it a good idea to have the inside of the exhaust ducts serving 
> pyrophoric gas equipment coated with teflon?
>
> Thank you very much for your help.
>
> Iulian