Swivel Ring Flange
Definition - What does Swivel Ring Flange mean?
A swivel ring flange is a two piece constructed flange used extensively for offshore pipelines and offshore industry applications. A swivel ring flange has a heavy forged welding hub that is fixed to a forged ring that can be rotated to serve as a mating flange to a weld neck or another flange. In a swivel ring flange, the rotating ring is held on by the welding hub that is in turn secured by a retaining ring.
A swivel ring flange is also known as a swivel flange.
Corrosionpedia explains Swivel Ring Flange
Swivel ring flanges are favored because they do not cause any problems in the alignment of bolt holes during sub-sea flange installation. Swivel ring flanges are available in various metals and specifications, including class 150 to class 2500 specifications and from 1 inch to 60 inches in diameter. These flanges are readily mated to any standard welded neck flange and are very similar to ASME / ANSI B 16.5 and MSS-SP44 standard flanges.
Swivel ring flanges are constructed using a specific grade of carbon steel or stainless steel having ASTM A105 specifications with a minimum yield of 42,000 psi pressure. Some extra thickness is provided at the welding end. These flanges are also manufactured using superior grade materials such as A694 or A707.