Metal plate processing

[Bobfromoh]

A hot rolled carbon steel stack (nothing special)was specified. It operates at about 200F, 2' diameter and about 30' tall. The fabricator built it out of cold rolled material. The project wanted to know if this was acceptable. I use ASME Section VIII all the time but this question doesn't come up. I don't see any problem at all. There is a ladder (probably A-36)that will be welded to the stack. However, the question just keeps getting asked...so I'm asking it here. Does anyone have an opinion?

 

[metengr]

Provided you had adequately stiffened the lower shell courses (by increased wall thickness) to accommodate wind loads, buckling load from the weight of the upper shell courses and to support the weight of a person on a ladder, and used good welding techniques, I don't see a problem. Was the stack painted to reduce exposure to atmospheric corrosion?

What are the flue gas contents?

 

[BillPSU]

Are you sure this is cold rolled material or is it possibly temper milled product. Some decoiled plate vendors have added a temper mill in the process. The temper mill will crush the scale and probably 75% falls off the product while the remainder is crushed into the surface and is tightly bonded. The product is usually extremely flat and can be mistaken from cold rolled.

I don't believe any fabricator would use cold rolled plate in place of hot rolled unless it was less than .25 thickness. The price penalty would be substantial.