Repsol Steel LLP is a trusted alloy steel flange supplier, supplying a comprehensive range of chrome-moly (Cr-Mo) alloy steel flanges to industrial buyers, EPC contractors, and procurement teams across Africa, USA, Mexico, Oman, and Europe. Alloy steel flanges are manufactured primarily from ASTM A182 grades F11, F22, F91, F5, and F9 — engineered to withstand high-temperature and high-pressure service where carbon steel flanges would lose strength. They are widely used in oil refineries, power plants, petrochemical units, and hydrogen service piping systems. We supply alloy steel flanges in weld neck, slip-on, blind, lap joint, socket weld, and threaded types — with full documentation, EN 10204 3.1 certification, and international packaging standards.
With over 25 years of combined industry experience and a proven export network, we serve clients across Africa, the United States, Mexico, Oman, and Europe — including refinery, power generation, petrochemical, hydrogen, and chemical processing facilities. Our supply operations are structured to meet the documentation, packaging, and compliance requirements of international industrial procurement — including Material Test Certificates (MTC), dimensional inspection reports, NACE compliance, H2S service documentation, PMI testing, and third-party certification where required.
Whether you require F11 alloy steel weld neck flanges for a refinery in Oman, F22 alloy steel slip-on flanges for a power plant in Mexico, F91 alloy steel blind flanges for a high-temperature steam system in Europe, or F5/F9 alloy steel flanges for petrochemical service in Africa or the USA — Repsol Steel LLP delivers the right alloy steel flange solution, on time, with complete export documentation.
A complete alloy steel flange supply portfolio covering weld neck, slip-on, blind, lap joint, socket weld, and threaded flanges — engineered for high-temperature and high-pressure piping systems across Africa, USA, Mexico, Oman, and Europe.
Alloy steel weld neck flanges with a long tapered hub that provides smooth stress distribution. Used in high-temperature and high-pressure piping systems where thermal expansion and cyclic loading are critical.
Grades: F11, F22, F91, F5, F9
Compliance: ASME B16.5, B16.47, EN 1092-1
Size Range: ½" to 60"
Alloy steel slip-on flanges slide over the pipe and are fillet welded at both ends. Cost-effective and easy to align, used in moderate-pressure and high-temperature piping systems.
Grades: F11, F22, F91, F5, F9
Compliance: ASME B16.5, B16.47, EN 1092-1
Size Range: ½" to 60"
Alloy steel blind flanges with no center hole, used to close off pipe ends, valves, and pressure vessel openings. Essential for isolation in high-temperature and high-pressure service.
Grades: F11, F22, F91, F5, F9
Compliance: ASME B16.5, B16.47, EN 1092-1
Size Range: ½" to 60"
Alloy steel lap joint flanges for use with stub ends in piping systems requiring frequent dismantling. The flange is free to rotate, allowing easy alignment of bolt holes.
Grades: F11, F22, F91
Compliance: ASME B16.5
Size Range: ½" to 24"
Alloy steel socket weld flanges for high-pressure and small-bore piping. The pipe is inserted into the socket and fillet welded, providing a strong, leak-proof joint in high-temperature service.
Grades: F11, F22, F91
Compliance: ASME B16.5
Size Range: ½" to 4"
Alloy steel threaded flanges (NPT/BSP) for utility piping, plus custom-manufactured alloy steel flanges in non-standard sizes, grades, and configurations per project specifications.
Grades: F11, F22, F91, F5, F9
Compliance: ASME B16.5, DIN
Size Range: ½" to 24"
Alloy steel flanges are supplied primarily in ASTM A182 chrome-moly (Cr-Mo) grades — designed to retain strength and resist creep at elevated temperatures across Africa, USA, Mexico, Oman, and Europe. The alloying elements (chromium and molybdenum) provide superior high-temperature strength, oxidation resistance, and hydrogen service capability compared to carbon steel. We supply alloy steel flanges in the following materials and grades:
All alloy steel flanges we supply are accompanied by Material Test Certificates (MTC to EN 10204 3.1) confirming the exact grade, mechanical properties, and heat number — ensuring full traceability and compliance with international project specifications. PMI testing, hardness testing, and NACE compliance documentation are available on request.
| Parameter | Specification |
|---|---|
| Flange Types | Weld Neck, Slip-On, Blind, Lap Joint, Socket Weld, Threaded, Orifice, Long Weld Neck |
| Materials | ASTM A182 F11, F22, F91, F5, F9, F92, F911 (Chrome-Moly Alloy Steel) |
| Size Range | ½" to 60" standard; larger sizes available on request |
| Pressure Classes | PN16, PN25, PN40, PN63, PN100 (EN 1092-1); Class 150, 300, 600, 900, 1500, 2500 (ASME B16.5) |
| Face Types | RF (Raised Face), FF (Flat Face), RTJ (Ring Type Joint) |
| Standards Compliance | ASME B16.5, ASME B16.47, ASTM A182, EN 1092-1, DIN, BS |
| Export Documentation | Commercial Invoice, Packing List, Bill of Lading, Certificate of Origin, MTC (EN 10204 3.1) |
| Inspection Options | PMI testing, hardness testing, ultrasonic testing, radiography, third-party inspection (SGS, BV, TUV, Intertek) available on request |
| Additional Documentation | NACE compliance, H2S service documentation, hydrogen service certification available on request |
Alloy steel flanges (chrome-moly) are designed for high-temperature and high-pressure service where carbon steel flanges would lose strength or suffer from creep. Before finalizing an alloy steel flange for projects in Africa, USA, Mexico, Oman, or Europe, our technical team recommends evaluating four key factors:
If you are unsure which alloy steel flange specification best suits your application, our technical team is available to review your piping drawings, process data, and project specifications — and recommend the most suitable alloy steel flange solution.
We have supplied alloy steel flanges to buyers across Africa, the USA, Mexico, Oman, and Europe — building a supply track record that reflects reliability, compliance, and on-time delivery.
Every alloy steel flange shipment is accompanied by complete export documentation — Commercial Invoice, Packing List, Bill of Lading, Certificate of Origin, Material Test Certificates (MTC to EN 10204 3.1), and third-party inspection reports on request.
Our alloy steel flanges comply with ASME B16.5, ASME B16.47, ASTM A182, EN 1092-1, DIN, and BS standards — ensuring that products meet the exact specifications of international industrial projects.
Alloy steel flanges are packed with rust-preventive coating and moisture-resistant export-grade packaging designed for long-distance sea, air, and road transport — protecting product integrity from factory to destination.
We support a range of Incoterms — FOB, CIF, CFR, EXW, DAP — and coordinate with trusted freight partners for sea, air, and multimodal shipments to major ports across Africa, USA, Mexico, Oman, and Europe based on buyer preference.
Our support team assists buyers with grade selection, alloy steel flange specification review, PMI documentation, and shipping coordination — ensuring a smooth experience at every stage.
Repsol Steel LLP supplies alloy steel flanges to a wide range of process industries across Africa, USA, Mexico, Oman, and Europe where high-temperature strength, hydrogen service capability, and reliable bolted connections are essential for safety and operational reliability.
F11, F22, and F91 alloy steel flanges supplied for high-temperature and high-pressure process piping in crude distillation, catalytic cracking, hydrocracking, and hydroprocessing units across Africa, USA, Mexico, Oman, and Europe.
F11, F22, and F91 alloy steel flanges supplied for superheated steam lines, boiler connections, turbine piping, and high-pressure auxiliary systems in thermal, combined-cycle, and ultra-supercritical power plants.
F11, F22, and F91 alloy steel flanges supplied for hydrogen service, hydrotreating, hydrocracking, and H2S environments — where carbon steel flanges are unsuitable due to hydrogen embrittlement.
F11, F22, F5, and F9 alloy steel flanges supplied for high-temperature reactors, heat exchangers, process piping, and fired heater connections in petrochemical plants.
F11, F22, and F91 alloy steel flanges supplied for high-temperature and high-pressure ammonia synthesis loops, urea plants, and hydrogen recovery units.
F11, F22, and F91 alloy steel flanges supplied for high-temperature wellhead equipment, gathering lines, and high-pressure gas processing systems in upstream, midstream, and downstream operations.
Alloy steel flanges supplied to fabrication units and EPC contractors for piping spools, skids, modular systems, and industrial assemblies — with quick turnaround times and documentation support.
Repsol Steel LLP is recognized as a reliable alloy steel flange supplier for procurement teams, EPC contractors, and maintenance projects across Africa, the USA, Mexico, Oman, and Europe. Our export documentation, packaging, and standard compliance are structured for smooth cross-border supply to buyers worldwide — ensuring your alloy steel flanges arrive on time, in specification, and ready for installation.
Africa: Refinery, mining, power & industrial piping projects
USA: Refinery, power generation, hydrogen & EPC supply
Mexico: Refinery, petrochemical & power industry projects
Oman: Oil & Gas, refinery, petrochemical & power projects
Europe: Refinery, power, petrochemical & hydrogen supply
All alloy steel flanges are supplied with material certificates, dimensional inspection reports, PMI testing, hardness testing, and third-party certification as required by project specifications.
Yes. We are a leading alloy steel flange supplier serving buyers across Africa, the USA, Mexico, Oman, and Europe — offering ASTM A182 F11, F22, F91, F5, F9, F92, and F911 chrome-moly alloy steel flanges in weld neck, slip-on, blind, lap joint, socket weld, and threaded types.
An alloy steel flange is a forged piping component made from chrome-moly (Cr-Mo) alloy steel (ASTM A182 grades). It is designed to retain strength and resist creep at elevated temperatures — making it essential for refinery, power plant, hydrogen service, and petrochemical piping systems where carbon steel would fail.
We supply alloy steel flanges in ASTM A182 F11 (1¼ Cr – ½ Mo), F22 (2¼ Cr – 1 Mo), F91 (9 Cr – 1 Mo – V), F5 (5 Cr – ½ Mo), F9 (9 Cr – 1 Mo), F92, and F911 chrome-moly grades.
F11 (1¼ Cr – ½ Mo) is used for moderate high-temperature service up to 550°C. F22 (2¼ Cr – 1 Mo) offers higher strength and is used up to 580°C in refinery and power plant service. F91 (9 Cr – 1 Mo – V) is an advanced high-strength alloy used up to 650°C in ultra-supercritical power plants and advanced refinery units. The higher the chrome content, the better the high-temperature strength and oxidation resistance.
Yes. We offer custom sizes, pressure classes, alloy steel grades, face types, and flange configurations based on drawings, piping specifications, and project requirements — with quick turnaround times.
Send us your alloy steel flange specifications, grade requirements, or drawings. Our export team will respond within 24 hours with a tailored quotation.
Repsol Steel LLP is a leading manufacturer and stockholder of high-quality piping products, serving the Oil, Gas, Petrochemical, and Nuclear industries with reliable engineering solutions.
Repsol Steels LLP Team Is Here to Help
Looking for reliable pipes, fittings, flanges, valves or other industrial piping products? Share your requirement and our team will help you find the right product, material and specification.