Underground Stainless
Underground Stainless
(OP)
We are replacing an underground water drain line from a process air system at 165 psig. Existing line is Carbon Steel. Customer plans to use a stainless water drain line in direct burial installation. Two questions arise in my mind -
1) is there any galvanic potential between 304SS and carbon steel?
2) Will soil chlorides give us a problem with buried stainless?
This is a rush job; any information will be helpful.
1) is there any galvanic potential between 304SS and carbon steel?
2) Will soil chlorides give us a problem with buried stainless?
This is a rush job; any information will be helpful.
Larry





RE: Underground Stainless
2. Depending on the Cl level, amount of moisture, wetting&drying, pH, temp. and the SS alloy, YES, you can easily expect thru-wall pitting and possible MIC attack in/near welds.
RE: Underground Stainless
We had all the problems mentioned by “Metalguy” with the worst being Chloride induced SCC on the exterior. It wasn’t always evident until you attempted to make a repair.
All the waste lines have been or are being brought above ground and the ones that had to remain underground have been changed to double containment.
RE: Underground Stainless
Thanks for confirming my suspicions.
Larry