The rules in part PB are applicable to pressure parts of boilers,including piping constructed under the provisions of this Section,that are fabricated by brazing.These rules shall be used in conjunction with the general requirements in Part PG and the specific requirements in the applicable parts of this Section that pertain to the type of boiler under consideration. The rules in part PB are not applicable to nonpressure bearing attachments to pressure parts that have essentially no load-carrying function(such as extended heat transfer surface,insulation support pins,etc)