Defining the How and When to Execute Single Stud Replacement (SSR) of Bolted Flanged Joints

Single Stud Replacement (SSR), or as currently known in ASME PCC-2 as “Hot Bolting” is the removal and replacement of studs on a bolted joint on a one at a time basis in a predetermined sequence. One of the key aspects in the successful execution of this activity is the determination of the appropriate maximum pressure governing the operation. The guidance currently provided in ASME PCC-2 is somewhat arbitrary and vague, and some clearer definition of a technical basis in this area would be valuable to industry in terms of both productivity and safety. To provide additional clarity to this activity, a Task Group within the ASME Post Construction Subcommittee on Flanged Joint Assembly is redrafting the article detailing procedures for Single Stud Replacement. This paper discusses the work and focuses on the task of determining and documenting a technical basis for setting the limits (e.g., maximum pressure, effects of external moments, etc.) to safely execute a Single Stud Replacement operation.