ASME Stainless Steel Vessel 2B Finish

[mechconst]

Our project has a 316L stainless steel pressure vessel, 48" diameter with ASME F&D heads that operates under 30 psig. The engineered spec indicates that the vessel is to have a Bright 2B Finish. Question: is the "Bright" 2B finish something performed at the steel mill or is this something done after fabrication using power tools in the shop?

 

[eliebl]

If memory serves the 2B finish is typical for stainless steel which comes in sheet thicknesses (i.e. gauge). If the thickness needs to be 3/16 (plate) then it would be a rough mill finish.

There is a guide somwhere which tells what the finishes mean. They will typically relate to cleanliness or ease of cleanliness. Most of the time with a surface roughness.

EJL

 

[unclesyd]

We used to have some flanged vessels of 48"x60" that required a mirror fiinish. This finish was achieved the old fashioned way with elbow grease. It was a rough job. It can be done if you have a manway for emchanic to enter the vessel.

 

[gr2vessels]

mechconst,
The Stainless Steel sheet metal you purchase for the fabrication of your vessel comes with a finish specified on your purchasing specification, including any other limitations you might require. The 2B finish is a standard, brite finish and usually is preserved by a protective plastic film layed on the sheet. The 2B finish is not normaly applicable to the finished product, unless some decorative appearance requirements have been specified in the vessel purchasing documentation. However, I have seen pressure vessels with the protective film attached untill the final inspection, the welds meticulously cleaned and polished. The final light polish of the welds was the only time a power tool came in the contact with this vessel. Laser cutting, highly polished rollers and low energy TIG were the fabrication "secrets".
cheers,
gr2vessels