Swivel flange is a kind of special weld neck flange whose outer ring allows 360° rotational of the inner ring for rapid alignment of bolt holes with the standard flange. the feature makes it ideal for offshore/subsea pipeline operations, which allows divers to adjust bolt holes more quickly and conveniently.
The swivel flange can be designed for any nominal sizes and pressure rating for flange specification and gaskets (Class 150-Class 2500, OD 1/2- 60 inch), specified in ASME B16.5, API 6A and MSS SP44. some manufacturers also supply non-standard swivel flange to suitable for some special applications according to customer request, for example, the cladding welding on inner ring or PTFE coating treatment on the surface of the flange, etc.
Swivel flanges can be made from materials to suit any pipe network, the common material including:
Stainless steel:ASTM A182 F 304/304L/316/316L/321/347, Duplex F51/F53/F44/F55/F60/F61;
Carbon steel: ASTM A105; API 6A AISI 4130
Alloy steel: ASTM A694 F52, F60, F65, F70, ASTM A707 and are also supplied to customer specifications.