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Re: Stainless in the fire
Posted: Mon Nov 21, 2011 9:24 pm
by DetroiTug
Just got a call from a buddy, a new steamboater as well, about a new Roberts type boiler he was buying. Thanks to this thread was able to deter him from making a bad decision. He was right on the verge of sending the check out for $4k. While talking, he mentioned it was all made professionally from stainless steel. He was glad he called.
-Ron
Re: Stainless in the fire
Posted: Tue Nov 22, 2011 9:08 am
by Mike Rometer
I'm led to believe that there are grades of stainless steel that are suitable for building boilers, that don't suffer from stress corrosion cracking, but if your local codes don't allow it, they don't allow it.
Re: Stainless in the fire
Posted: Tue Nov 22, 2011 2:54 pm
by fredrosse
The ASME Boiler & Pressure Vessel Code prohibits the use of "Austenitic Stainless Steels" for wetted parts of the boiler. This includes the 200 Series and 300 Series Stainless Steels. The most common stainless steels encountered are Types 304 and 316, probably 90+ % of the stainless steel used is 304 or 316, and they are prohibited for use in the wetted parts of the boiler. Other common grades: 201,203, 301,302, 303, 304L, 305, 308 (weld wire), 309, 316L, 317, 321, 347.
These stainless steels however are commonly used as tubing in various liquid heat exchangers, fluid system tubing, instrument tubing, etc. They are legal for the "non-wetted" parts of a boiler, such as superheater tubing.