Titanium Flanges
Giriraj Impex is a manufacturer, stockist, supplier and exporter of titanium flanges from ASTM B381 / ASME SB381 forgings in grades F-2, F-5, F-7 and F-12. We manufacture titanium flanges to ASME B16.5 from ½" to 24" NB in Class 150 to 2500, to ASME B16.47 for larger sizes, and to EN 1092-1, in weld neck, slip-on, blind, socket weld, threaded and lap joint types, and titanium stub ends with loose backing flanges, with mill test certificates.
Titanium flanges are used in seawater, chlorine, bleach and chemical piping where stainless steel and copper-alloy flanges would corrode, and in offshore systems where their low weight is also an advantage.
Specifications
| Item | Details |
|---|---|
| Material | ASTM B381 / ASME SB381 forgings – F-2 (Grade 2), F-5 (Grade 5), F-7 (Grade 7), F-12 (Grade 12); others on request |
| Dimensional standards | ASME B16.5, B16.47 Series A and B, B16.48; EN 1092-1 |
| Sizes | ½" to 24" NB (B16.5); larger to B16.47 |
| Classes | 150, 300, 600, 900, 1500, 2500; PN ratings to EN 1092-1 |
| Types | Weld neck, slip-on, blind, socket weld, threaded, lap joint, reducing, spectacle blind; stub ends with loose backing flanges |
| Facings | RF, FF, RTJ |
| Condition | Annealed |
| Documents | Mill test certificate (MTC); third-party inspection on request |
Chemical composition and mechanical properties
| Grade | UNS | N | C | H | Fe | O | Al | V | Other |
|---|---|---|---|---|---|---|---|---|---|
| Grade 1 | R50250 | 0.03 | 0.08 | 0.015 | 0.20 | 0.18 | – | – | – |
| Grade 2 | R50400 | 0.03 | 0.08 | 0.015 | 0.30 | 0.25 | – | – | – |
| Grade 5 | R56400 | 0.05 | 0.08 | 0.015 | 0.40 | 0.20 | 5.5–6.75 | 3.5–4.5 | – |
| Grade 7 | R52400 | 0.03 | 0.08 | 0.015 | 0.30 | 0.25 | – | – | Pd 0.12–0.25 |
| Grade 12 | R53400 | 0.03 | 0.08 | 0.015 | 0.30 | 0.25 | – | – | Mo 0.2–0.4, Ni 0.6–0.9 |
Hydrogen limits differ slightly between product forms; residual element limits as given in each ASTM specification.
| Grade | Tensile strength, MPa (ksi) | Yield strength 0.2%, MPa (ksi) | Elongation, % |
|---|---|---|---|
| Grade 1 | 240 (35) | 138 (20) | 24 |
| Grade 2 | 345 (50) | 275 (40) | 20 |
| Grade 5 | 895 (130) | 828 (120) | 10 |
| Grade 7 | 345 (50) | 275 (40) | 20 |
| Grade 12 | 483 (70) | 345 (50) | 18 |
Grades 1, 2 and 7 also have maximum yield strength limits. Values are typical of ASTM B265 and B348; check the specification for the product form.
B381 forging grades F-2, F-5, F-7 and F-12 correspond to Grades 2, 5, 7 and 12. Background is on the titanium page.
Solid flanges or stub ends with backing flanges
Because titanium costs more than steel, many titanium piping systems use a titanium stub end welded to the pipe, with a loose backing flange in carbon steel, coated steel or stainless steel. Only the stub end is wetted by the process fluid, so titanium is used only where it is needed, and the loose flange rotates for easy bolt alignment. The backing flange can be lined or coated if external corrosion is a concern. Solid titanium flanges are used where the whole flange is exposed to a corrosive environment – such as seawater spray offshore – or where the project specification requires them, and blind flanges in titanium are used where the blind face is wetted.
Pressure ratings and grade choice
Commercially pure Grade 2 has a lower yield strength than carbon steel, so solid Grade 2 flanges have lower pressure-temperature ratings than A105 flanges of the same class; the ratings for the actual material and design temperature should be confirmed from the applicable standard. Where higher strength is needed, Grade 5 or Grade 12 flanges are used. Grade 7 and Grade 12 also give better resistance to crevice corrosion under gaskets in hot chloride service, which is a common failure point in titanium systems running above about 70 °C.
How we manufacture titanium flanges
Titanium flanges are machined from forged blanks or rings to ASTM B381, forged to shape and annealed. Machining covers the bore, facing, hub, flange thickness and bolt holes to ASME B16.5 or the specified standard, with a serrated or smooth face finish as ordered. Titanium is machined with sharp tools, low speeds and plenty of coolant, and swarf is handled safely. Every flange is marked with grade, specification, size, class, facing and heat number and inspected before dispatch.
Gaskets and bolting
Gaskets for titanium flanges must suit the service and avoid crevice corrosion: PTFE-based and expanded PTFE gaskets are common for chemical service, and compressed fibre or elastomer gaskets for seawater. Graphite gaskets should be checked for compatibility, as graphite is noble to titanium in seawater. Bolting can be coated steel for backing flanges or titanium Grade 5 or other corrosion-resistant studs for solid flanges exposed to seawater.
Ordering titanium flanges
Please give the grade, flange type or stub end and backing flange, size, class, facing and face finish, bore or pipe schedule, quantity and any testing or inspection requirement. Flanges are packed in wooden boxes with faces protected.
Applications and related products
Titanium flanges are used in seawater cooling and firewater systems, desalination, offshore platforms, chlor-alkali and bleach plants, and chemical processing. Matching products include titanium pipes and tubes, titanium pipe fittings, titanium sheets and plates, titanium round bars and titanium fasteners. Flanges in other materials are on the flanges page.
Frequently Asked Questions
Titanium flanges are made from forgings to ASTM B381 (ASME SB381), with dimensions to ASME B16.5, B16.47 or EN 1092-1.
F-2 is the ASTM B381 forging grade corresponding to commercially pure titanium Grade 2, the most common grade for titanium flanges.
Only the stub end is wetted, so titanium is used only where needed, and the loose steel backing flange reduces cost and makes bolt alignment easy.
No. Grade 2 titanium has a lower yield strength than carbon steel, so its ratings in a given class are lower. Grade 5 or 12 is used where more strength is needed.
PTFE-based gaskets for chemical service and compressed fibre or elastomer gaskets for seawater are common; graphite should be checked for compatibility.
Weld neck, slip-on, blind, socket weld, threaded, lap joint, reducing flanges, spectacle blinds and stub ends with backing flanges.
Request a Quote for Titanium Flanges
Tell us the product, grade, size, standard, quantity and delivery location, and our sales team will reply with a quotation.