304 Stainless Piping in Skid Operation

[justonwo]

I'm currently designing a skid that will be installed in a building isolated from precipitation and low temperature in the midwest.

We are specifying 304 stainless for the piping - my experience with 304 is that is quickly rusts in an outdoor environment. Is 304 acceptable for piping indoors? Does it need to be painted generally speaking? Or is unfinished ok?

Many thanks.

 

[Montemayor]

Justonwo:

I used 304ss piping in a skid-mounted process plant located indoors as well in storage and transfer facilities outdoors in the US midwest - Decatur, IL, to be specific.

I never experienced any "rusting" on the pipes - either outdoors or indoors. I also used 304ss in many other processes in places such as Cedar Rapids, IA, Omaha, NE, and Conroe, TX. Again, I never witnessed or heard of any rusting.

Are we talking about the same alloy? After all, it is called STAINLESS steel - isn't it? Oxygen will not attack it at the conventional temperatures of approximately -50 oF to 150 oF. Something else must be attacking your piping; I don't think it is oxygen.

 

[justonwo]

My experience is with 304 used as exhaust piping for diesel stationary diesel engines, so you can bet the temperature is well above 150 F. That is most likely the reason for the corrosion I saw.

Thanks for the input!