A swivel ring flange is a type of flange that is designed to allow the pipeline to rotate or swivel, which helps to reduce the stress on the pipeline caused by thermal expansion, movement, or vibration. It consists of a forged ring and a welding hub that is attached to the pipeline. The ring is free to rotate around the hub, which allows for axial rotation, lateral movement, and angular misalignment of the pipeline.

The swivel ring flange is typically used in pipelines that are subject to thermal expansion and contraction, such as in steam or hot water systems. The ability of the swivel ring flange to rotate and absorb the movement helps to prevent damage to the pipeline and prolongs the life of the system. The flange is available in various sizes, pressure ratings, and materials, including carbon steel, stainless steel, and alloy steel.

Proper installation and torque of the bolts are crucial to ensure a tight and leak-free seal. The swivel ring flange must be installed with enough clearance to allow for the required movement, and the bolts must be tightened to the specified torque to prevent the flange from coming loose. Regular inspection and maintenance of the swivel ring flange are also important to ensure that it is functioning properly and to prevent any damage or leaks in the system.