Swivel Ring Flange — ISO 27509 / project specs
Also written SRF
Swivel ring flange — a flange with a rotating ring that allows bolt holes to be aligned after welding. Swivel ring flanges speed up subsea and offshore tie-ins and riser connections, where rotating the whole pipe to line up bolt holes is not possible.
- ISO 27509 / project specs
- 23 grades
- EN 10204 3.1 / 3.2
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is a swivel ring flange?
A swivel ring flange is a flange with a rotating ring that allows bolt holes to be aligned after welding. Swivel ring flanges speed up subsea and offshore tie-ins and riser connections, where rotating the whole pipe to line up bolt holes is not possible.
Standards for swivel ring flanges
Swivel Ring Flange: What to Know Before Ordering
- Hub welded to pipe; ring rotates
- Common on subsea and offshore lines
- Made to ISO 27509 / DNV or project specs
Swivel Ring Flange Materials & Grades
| Grade | Material standard | Best for |
|---|---|---|
| Inconel 825 swivel ring flange | ASTM B564 | Sulphuric and phosphoric acid service, chloride stress-corrosion cracking and sour gas |
| SS 904L swivel ring flange | ASTM A182 F904L | Dilute sulphuric acid, phosphoric acid and chloride-bearing cooling water |
| SS 304 swivel ring flange | ASTM A182 F304 | General corrosion resistance, food, water and architectural work |
| SS 304L swivel ring flange | ASTM A182 F304L | Welded tanks, piping and vessels in general corrosive service |
| SS 310 / 310S swivel ring flange | ASTM A182 F310 | Furnaces, burners and heat treatment at high temperature |
| SS 316 / 316L swivel ring flange | ASTM A182 F316L | Chloride-bearing process fluids, marine air and pharmaceutical service |
| SS 321 swivel ring flange | ASTM A182 F321 | High-temperature service between 425 and 815 °C |
| SS 347 swivel ring flange | ASTM A182 F347 | Welded high-temperature piping in refineries and power plants |
| Duplex 2205 swivel ring flange | ASTM A182 F51 / F60 | Strength with chloride resistance at a stainless-steel budget |
| Super Duplex 2507 swivel ring flange | ASTM A182 F53 | Seawater and high-chloride service where strength also matters |
| Inconel 600 swivel ring flange | ASTM B564 | High-temperature oxidation, caustic and nuclear service |
| Inconel 625 swivel ring flange | ASTM B564 | Seawater, high strength and high temperature in one alloy |
| Inconel 718 swivel ring flange | project / purchase specification dependent | Very high strength at temperatures up to about 650 °C |
| Incoloy 800 / 800H / 800HT swivel ring flange | ASTM B564 | Furnaces, petrochemical heaters and high-temperature piping |
| Hastelloy C276 swivel ring flange | ASTM B462 / B564 | The most aggressive mixed acids, wet chlorine and hypochlorite |
| Hastelloy C22 swivel ring flange | ASTM B462 / B564 | Mixed oxidising and reducing acids, and weld overlays |
| Monel 400 swivel ring flange | ASTM B564 | Seawater, hydrofluoric acid and marine service |
| Monel K500 swivel ring flange | project / purchase specification dependent | High-strength pump shafts, bolting and springs in seawater |
| Super Duplex S32760 swivel ring flange | ASTM A182 F55 | Seawater firewater, injection and offshore piping |
| ASTM A106 Gr B swivel ring flange | ASTM A105 | High-temperature process and steam piping in refineries and power plants |
| ASTM A333 Gr 6 swivel ring flange | ASTM A350 LF2 | Cold-climate and refrigerated piping down to −45 °C |
| ASTM A335 P11 swivel ring flange | ASTM A182 F11 | Steam and hot-oil piping up to about 550 °C |
| ASTM A335 P22 swivel ring flange | ASTM A182 F22 | High-pressure steam and hydrogen service up to about 580 °C |
Other flanges
Swivel ring flange — questions buyers ask
What is a swivel ring flange?
A swivel ring flange is a flange with a rotating ring that allows bolt holes to be aligned after welding. Swivel ring flanges speed up subsea and offshore tie-ins and riser connections, where rotating the whole pipe to line up bolt holes is not possible.
Where are swivel ring flanges used?
Mainly in subsea and offshore pipelines, risers and spools where alignment in place is difficult.
Which grades are swivel ring flanges available in?
Inconel 825, SS 904L, SS 304, SS 304L, SS 310 / 310S, SS 316 / 316L, SS 321, SS 347, Duplex 2205, Super Duplex 2507, Inconel 600, Inconel 625, Inconel 718, Incoloy 800 / 800H / 800HT, Hastelloy C276, Hastelloy C22, Monel 400, Monel K500, Super Duplex S32760, ASTM A106 Gr B, ASTM A333 Gr 6, ASTM A335 P11, ASTM A335 P22.
Which standard covers swivel ring flange dimensions?
ISO 27509 / project specs. The material standard depends on the grade.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026