pump corrosion protection

[linford]

we will be acid-washing some pumps soon. what sorts of products help prevent the acid from tearing aparat the pumps? The acid will be in pretty low concentration.

 

[unclesyd]

Got to have more information
Material of construction of pumps?
What type acid, with temperature and concentaration?

It is always better if you can use a commercial product that is compunded for a particular set of coditions.

 

[linford]

yeah. stainless steel shaft and impeller.
Acid will be acetic, but the concentration is tbd. We want to consider the corrosive effects of the acid in determining the strength.

 

[unclesyd]

Acetic acid can be very agressive to some stainless, so watch out.

We used a 20 % by volume Glacial Acetic Acid in water at 100°C on 304L S/S with no Problems. The corrosion rate was not measurable. We limited the time of exposure to 4 Hrs per cleaning. We actually used the 20% Acetic Acid on 304L at 220°C under pressure for short peroids of time with no problems.

Remeber to keep your concentration and temperature as low as possible. Acetic Acid doesn't have very good wetting properties so you may have to add a wetting agent.

Heating the acid will create a lot of fumes. The exposure level for Acetic acid has been lower so check on personnel exposure. I don't know the new TLV but it has changed the methods we did use.