tox662 - 7-11-2016 at 01:58
Hello, I have been constructing a fume hood so that I can do more inside my lab/shed. The housing is wood, with Plexiglas for the front. The air is
being pulled by 2 explosion proof bilge fans outside through some PVC ducting. Does this sound alright for general chemistry? specifically will the
presence of nitric or sulfuric acid vapors cause damage to the ducting? I want to do some nitrating of cotton and such in there.
Metacelsus - 7-11-2016 at 06:36
It should be OK; just make sure to periodically inspect it.
careysub - 7-11-2016 at 07:39
PVC is rated for use with sulfuric acid of any concentration less than "fuming" at room temperature, and is considered moderately resistant to nitric
acid up to 70%. Further, the actual exposure of PVC from fumes is slight (quite different from using it as a storage container).
See:
http://www.calpaclab.com/pvc-polyvinyl-chloride-chemical-com...
What PVC is most vulnerable too is some powerful solvents, principally acetone, halogenated hydrocarbons, and aromatic hydrocarbons.
I would expect though that any solvent vapor would simply render the PVC surface temporarily soft and sticky, from which it would recover after the
solvent evaporates off (this what happens when you smear it with purpose-made PVC solvent). PVC of every schedule has thick walls, so any chemical
attack from vapor would be hard pressed to undermine its integrity.
aga - 7-11-2016 at 08:09
Sounds great !
My 'hood ducting is PVC and works fine.