Description & application useSwivel Ring Flange sets consist of a butt weld swivel hub with a rotatable outer bolt ring which allows for easier alignment of the bolts to the mating flange. For all piped applications Swivel Flanges can save considerable installation time. Freudenberg Oil & Gas Technologies provides a full range of swivel flanges to suit all classes of ASME B16.5 and B16.47 flanges. All our flanges benefit from the extensive experience that FO> has gained in over 25 years of flange design, development and manufacture.
Are all Swivel Flanges designed the same?
There is no international standard for swivel ring flanges and this can lead to under design on a fundamental level. Whilst the ASME 16.5 and 16.47 codes are applicable for weld neck flanges, they are not applicable to swivel ring flanges beyond the bolt pattern and bolt sizes. ASME offer alternative rules that consider swivel ring flanges as non-standard, or loose type, flanges, but detailed design and Finite Element Analysis (FEA) has to be conducted to ensure components are not undersized or over stressed.
The effect of undersized, or “lightweight”, designs can often be seen on site with deformed and bent swivel rings, which in turn results in bending of the bolts and potential loss of gasket seating force. Care must also be taken to avoid mismatch between the flexural properties of the swivel flange and the mating weld neck flange. By ensuring these properties are well matched, an even compression on the sealring is obtained, thereby minimising the opportunity for bolts to be overtightened
Freudenberg Oil & Gas Technologies removes these potential modes of failure at the design stage. FO> prefers to manufacture the swivel rings using high strength carbon steel, with a design process supported by inhouse software and FEA. The hub would be manufactured to the customer’s mating material specification.
Vector swivel flanges also feature a stainless steel retaining circlip that holds the swivel ring in place during assembly. This can be easily removed and refitted, allowing the swivel ring and hub interface to be lubricated for easy rotation during installation. This circlip replaces more complex retaining methods such as welded retainer clips.
Recessed metal retaining circlip
Swivel Flange features
MaterialSwivel Flange hubs can be manufactured from materials to suit any pipe network. Freudenberg Oil & Gas Technologies has experience in the production of connectors from carbon steel, Duplex, Super Duplex, Stainless Steels, Nickel Alloys and specialist materials. Swivel rings are made from high strength carbon steel. Swivel flanges hubs can be supplied with Nickel Alloy or stainless steel inlay to the seat areas when necessary to meet erosion or corrosion requirements.
BoltingBolt sets for swivel flanges are supplied to meet the client’s specifications. Longer bolts are required compared to weld neck flanges to accommodate the increase thickness of the swivel ring. All materials, coatings and types of bolting
can be supplied. Customer to advise if bolt tensioning will be used.
CoatingA wide variety of coating and paint systems are available using our in-house blasting and coating facility.