corrosion of B7 bolts

[wayas]

Is it correct to use A193 B7 Bolts for stainless steels flanges e.g mono flanges, We used it in some cases and we discovered that it was corroding.

 

[BigInch]

I believe the spec covers carbon steels and a number of stainless steel materials as well. You should specify the bolt material that is most compatible with your pipe.

 

[MickMc]

As BI states A193 B7 are commonly used in both CS and SS materials and if corroding I suspect may be due to particular environment and should be coated to protect e.g. hot dip galvanizing.

 

[MJCronin]

I agree with MickMc ..... Bolt coatings are the way to go. Consider PTFE coated nuts and bolts (Xylan) have been in use for decades

http://www.eng-tips.com/viewthread.cfm?qid=325662

http://www.eng-tips.com/viewthread.cfm?qid=364184

MJCronin
Sr. Process Engineer