My question is this,,,,whyare they different boiler stamps,,,on locomotive boilers...what makes a type S stamp,,,,different from a A....
The reason why I am asking,,,the WW&F is haveing a boiler built,,,by the Boothbay railroad,,in Boothbay,Maine,,,,meeting the current,,,FRA,,,boiler codes,,,,useing a type S stamp,,,,,,thanks Pat

A company holding an "S" stamp is certified for the construction of power boilers (above 15 psi steam, 160psi water and above 250 degrees operating pressure). A company holding an "R" stamp is able to also make repairs to a boiler.

Jason

As an Operating Engineer I should know about the "A" code stamp, but had to look it up. The "A" stamp is a ASME certification of the shop to actually build the boiler,the "S" stamp is the certification of the boiler itself, "R" for repair,"AI" for authorized inspector, etc. as laid out in the International Boiler and Pressure Vessel Code. Hope this helps.

Generally a boiler a boiler shop has to go through rigorous testing, procedures and maintain a high level of quality assurance to hold an ASME pressure vessel stamp. The type of stamp held depends on what type of work the company applying for wishes to conduct. A company can hold all or perhaps just one. For instance a boiler shop can have an R stamp for repair only or maybe and R and an S. It just depends on the type of work the shop wishes to do and is qualified to do.

Rather than copy all this to the list here are the different stamps and designations. http://www.fmtuevbv.de/asme_code.htm

The S stamp on your boiler designates that the company holding the ASME certification is qualified to build a power boiler that exceeds 15psi steam, 160psi water and 250f degrees water temp. The S stamp also covers PP or piping.