Class 900 Studding Outlets

Class 900 Studding Outlets are heavy-duty branch connections for very high-pressure piping and vessel applications. The substantial pad thickness and flange section at Class 900 result in a robust connection that can handle the extreme forces generated by high internal pressures acting on the branch opening.

The weld preparation between the studding outlet base and the header pipe at Class 900 requires full-penetration welds with post-weld heat treatment per the applicable piping or vessel code. Radiographic or ultrasonic examination of the completed weld is standard practice for Class 900 service.

Applications include branch connections on high-pressure separator inlet headers, reactor feed piping, and synthesis gas loops. The available outlet size range at Class 900 is more limited than lower classes, typically covering NPS 3/4 through NPS 3 on header sizes up to NPS 24.