Selection of Pressure vessel plate for corrosion service

[mechnas]

We are in the process of replacement of existing column having Mono Ethanol Amine Service, and making comparison between use of A 516 Gr. 60 & 70 plates. From the mechanical strength perspective, Gr 70 is a superior material. However, from the corrosion side, Gr. 60 have more advantage, from the failure histories observed with these material. Please provide some more data for making suitable selection for the intended service.

 

[weldstan]

Today grade 60 and 70 are often dual certified. So with greater thickness when designing with grade 60 lowered applied stress is incurred. In the 1970s and 1980s there was real difference in carbon equivalent between the grades and HAZ hardness was lower using grade 60 in the as welded condition. Thus the grade 60 material was less susceptible to SSC.