L-005 Standard Manufacturers
NORSOK Standard Flanges: Dimensions | Specifications | Material Grade | Standards | About NORSOK L-005 Flange | All Product Types
NORSOK Flanges are specialized piping components engineered according to the NORSOK L-005 standard, a key specification developed by the Norwegian petroleum industry to enhance safety, efficiency, and uniformity in offshore and subsea oil & gas operations. These flanges are crucial for high-performance piping systems used in harsh environments, particularly in the North Sea and Arctic installations, where extreme pressures and temperatures are common. Unlike conventional flange standards, NORSOK-compliant flanges are designed to withstand not only mechanical stress but also severe corrosion due to seawater exposure and sour service conditions.
We supply a wide range of NORSOK standard flanges, including Weld Neck, Blind, Socket Weld, Threaded, Lap Joint, and Orifice flanges, available in Class 150 to Class 2500 pressure ratings and sizes ranging from ½″ NB to 48″ NB. These flanges conform to NORSOK L-005, along with complementary international requirements like ISO 15156 (NACE MR0175) for sour service, PED 2014/68/EU, and EN 1092-1 tolerances. Face finishes are available in Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF), and custom machined designs depending on process requirements. Special surface finishes and sealing faces are offered for subsea bolting and hydrocarbon containment applications.
Materials offered include Carbon Steel (ASTM A105, A350 LF2), Stainless Steel (304/304L, 316/316L), Duplex (UNS S31803), Super Duplex (UNS S32750 / S32760), Inconel (625, 825), Alloy 20, Hastelloy C276, and other high-performance alloys, with full material traceability and certification. Each flange is supplied with inspection reports, ultrasonic testing (UT), hydro test data, and EN 10204 3.1 or 3.2 certificates, making them suitable for critical installations in offshore rigs, FPSOs, subsea manifolds, process modules, refineries, and LNG terminals.
As a global manufacturer and exporter of Norwegian standard flanges, we deliver NORSOK-compliant flanges to countries like Norway, UK, Netherlands, UAE, Saudi Arabia, Singapore, and Malaysia, supporting major EPCs and offshore contractors. We offer custom-machined NORSOK flanges based on project drawings or dimensional standards with tight machining tolerances and corrosion-resistant coatings. Whether you require standard stock items or engineered flange solutions tailored to offshore platform specifications, we ensure consistent quality, on-time delivery, and full compliance with Norwegian offshore regulations.
For complete technical details, including dimensions, pressure rating classes, weight charts, sizes, tolerances, and material specifications of our NORSOK L-005 Standard Flanges, please download the full Catalog PDF below.
Specification | Details |
---|---|
Standard | NORSOK L-005, based on ISO 7005, EN 1759, and ASME B16.5/B16.47 as applicable |
Flange Types | Weld Neck, Blind, Slip-On, Threaded, Socket Weld, Compact Flanges (CF), and RTJ types |
Size Range | ½″ NB to 60″ NB (DN15 to DN1500) |
Pressure Ratings | Class 150, 300, 600, 900, 1500, 2500 | PN6 to PN400 |
Face Types | Raised Face (RF), Ring Type Joint (RTJ), Compact Flange Face (as per NORSOK design) |
Tolerances | As per ISO 27509 and NORSOK dimensional tolerances |
Surface Finish | 3.2 – 6.3 μm (Stock Finish), Spiral Serrated, Smooth Face |
Testing & Certification | EN 10204 Type 3.1 / 3.2, NORSOK M-650 Qualification, NACE MR0175/ISO 15156 |
Application Sectors | Oil & Gas (Offshore & Onshore), Petrochemical, Marine Engineering, FPSOs, Subsea Installations |
Coating Options | Rust Preventive Coating, PTFE, Hot Dip Galvanized, Epoxy Coating (On request) |
Origin | Made in India (by Nutech Overseas) |
Export Network | USA, Europe, and Middle East |
Material Category | NORSOK L-005 Flange Grades |
---|---|
Stainless Steel NORSOK Flange | ASTM A182 F304 / F304L / F304H, F316 / F316L / F316Ti, F310, F309S, F317 / F317L, F321 / F321H, F347 / F347H, F904L, ASTM A351 CF3 / CF3M / CF8 / CF8M / CF8C, DIN 1.4301, 1.4306, 1.4307, 1.4311, 1.4401, 1.4404, 1.4408, 1.4409, 1.4541, 1.4571, 1.4550, 1.4435, 1.4539 |
Duplex Steel NORSOK Flange | ASTM A182 F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61, UNS S31803 / S32205 |
Super Duplex Steel NORSOK Flange | ASTM A182 F53 / F55 / F57 / F59 / F60 / F61, UNS S32750 / S32760 |
Carbon Steel NORSOK Flange | ASTM A105 / A105N, ASTM A350 LF2, ASTM A694 F52 / F56 / F60 / F65 / F70 / F80, ASTM A216 WCB, DIN 1.0460 / 1.0402 / 1.0619, Die Steel, Mild Steel |
Alloy Steel NORSOK Flange | ASTM A182 F5 / F9 / F11 / F12 / F22 / F91, AISI 4130 / 4140 |
Nickel Alloy NORSOK Flange | Nickel 200 / 201, ASTM B564 |
Monel NORSOK Flange | Monel 400 (UNS N04400), Monel K500 (UNS N05500), ASTM B564 |
Inconel NORSOK Flange | Inconel 600 / 601 / 625 / 690 / 718 / 783 / X750, ASTM B564 |
Incoloy NORSOK Flange | Incoloy 800 / 800H / 800HT (UNS N08800), Incoloy 825 (UNS N08825), Incoloy 925, ASTM B564 |
Hastelloy NORSOK Flange | Hastelloy C276 (UNS N10276), C22 (UNS N06022), C4, C2000, B2, B3, X, ASTM B564 |
Alloy 20 NORSOK Flange | Alloy 20 / 20Cb-3, Carpenter® 20, ASTM B462 |
254 SMO NORSOK Flange | SMO 254 / 6Mo, UNS S31254, DIN 1.4547, ASTM A182 |
Copper Nickel NORSOK Flange | Copper Nickel 90/10 (C70600), 70/30 (C71500), UNS C71640, ASTM B61 / B62 / B151 / B152 |
Copper NORSOK Flange | TP1, TP2, T1, T2, C10100–C12300, C14200–C17200, C21000–C71520, including C10930, C11000, C11400, C12000, C12200, C26000, C28000, C33000, C44300, C70600, etc. |
Brass NORSOK Flange | Grades 3602, 2604, H59, H62, etc. |
Aluminium NORSOK Flange | Aluminium Grades 5052, 6061, 6063, 2017, 7075, etc. |
Titanium NORSOK Flange | ASTM B381 Gr.1 / Gr.2 / Gr.4 / Gr.5 / Gr.7, UNS R50250 / R50400 / R50550 / R50700 / R52400 / R53400 / R56320 / R56400 |
Other Special Grades | Al6XN, Tin Bronze, Aluminium Bronze, Lead Bronze, Nimonic 75 / 80A / 90 |
NORSOK flanges are designed to meet the rigorous demands of the offshore oil and gas sector, primarily in Norway and the North Sea. Unlike general ASME or EN flanges, NORSOK flanges follow the NORSOK L-005 specification, incorporating enhanced features for corrosion resistance, pressure integrity, and safety in hostile marine environments.
Key differences include:
These differences make NORSOK flanges a preferred choice for subsea, topside, and FPSO applications, where reliability and safety are critical.
While NORSOK flanges share certain dimensional similarities with international standards like ASME B16.5 or EN 1092-1, they are not always interchangeable due to specific technical and certification differences:
For critical offshore and subsea applications, always verify full compliance — mixing standards without engineering validation is not recommended.
NORSOK flanges are specifically engineered to meet the rigorous demands of the Norwegian oil and gas sector, but their usage has expanded into other high-risk, high-performance industries due to their robust specifications. They are commonly used in:
Key reasons why NORSOK flanges are preferred:
This wide industry acceptance stems from NORSOK’s commitment to safety, durability, and lifecycle cost efficiency.
NORSOK flanges are specially developed to meet the harsh demands of offshore oil and gas platforms, especially where sour service (H₂S exposure), high salinity, and temperature fluctuations are prevalent. To ensure long-term integrity under such conditions, the standard enforces stringent metallurgical and mechanical requirements:
Key material integrity factors include:
These features make NORSOK flanges ideal for subsea systems, risers, pipelines, and topside equipment, where failure is not an option.
At Nutech Overseas, we proudly export high-quality NORSOK standard flanges to some of the most demanding offshore and subsea engineering markets across the globe. These include:
Major Export Destinations:
All flanges are shipped with full material traceability, 3.1/3.2 certification, and packaging suited for international transport. We provide customized export documentation, marking as per project specs, and fast delivery timelines — making us a trusted global supplier of NORSOK-compliant flanges.