Metal finishing Q&As since 1989

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Ventilation in Passivation

We are a fairly new company and we do not have a proper ventilation system in place in our Passivation Room. Any ideas welcome!

Fabiola Solorzano
Surgical Power & Accessories - Ventura, California, USA
2006

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First of two simultaneous responses --

Contract the work out. You will have rust on every steel part in a year or so.

James Watts
- Navarre, Florida
2006

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Second of two simultaneous responses -- 2006

Hi Fabiola

What in the HECK is a passivation room?

Pardon my abysmal ignorance .... I look, we look, forward to your educating us lowly peons .... but if you had said Assay ventilation or bright dip, we'd be clued in.

I am reminded of a medical student's reply to a judge for some minor infraction. He said ...

I am recuperating from the traumatic perosynivitis of the flexor dignatorium sublimus in the profundus muscle at the metacarphagal joint.

Heck, I can understand maybe one of two of those words but PASSIVATION ROOM ? Yucks.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

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From the context, I'd assume a passivation room is the place where their stainless steel instruments receive a passivation treatment by immersion in nitric acid.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

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James,

Due to the size of our Passivation Room (24' x 10'), one of our engineers suggested creating a box of acrylic plexiglass material (for each cell-3 total- box size:20" x 32") connected to an exhaust hood that includes a fume scrubber. Due to my lack of expertise in this field, I'm unsure wether this would be the most efficient way to solve our problem.

Greatly appreciate your comments and suggestions,

Fabiola

Fabiola Solorzano
Surgical Power & Accessories - Ventura, California, USA
2006

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There are specialists in this field. KCH Services is one who could handle this for you. Acrylic is not nearly as acid resistant as PVC or polypropylene. But due to the flammability of polypropylene, it's not a good material for exhaust ducts. So think you should be planning on a PVC exhaust system.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

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Hi Fabiola,

Re acrylic ... presupposing you are using nitric... make very, very sure that it is post heat treated (to remove stresses).

As Ted says, PVC is the ideal material for the ducting. Cheap. Large size range. Easy to instal. Very acid resistant. UV resistant, sorry, the grey PVC is !

But PP and Acrylic will both burn, albeit slowly. I would not use them.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2006

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You could also choose to get away from nitric entirely and switch to a much safer citric acid based passivation system. Let us know if we can help.

Ray Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2006