Dimensions & Pressure Ratings
API 605 Standard Flanges: Dimensions | Specifications | Material Grade | Standards | About API 605 | All Product Types
API 605 flanges, once a standard for large-diameter steel pipe flanges, have now been officially replaced by ASME B16.47 Series A flanges. However, many industries still refer to these high-diameter flanges as "API 605 flanges" in technical specifications, making it an essential keyword in procurement and design.
At Nutech, we manufacture and export a wide range of API 605-type flanges, strictly following the dimensional and tolerance requirements of ANSI/ASME B16.47 Series A. These flanges are designed for pipelines with sizes ranging from 26″ to 60″ NB and are available in pressure classes Class 150, 300, 400, 600, and 900.
Our large diameter flanges are engineered for critical applications such as oil & gas transmission lines, petrochemical process systems, seawater intakes, and pressure vessel connections. The flange face types include Raised Face (RF) and Ring Type Joint (RTJ) to meet the sealing needs of different industries.
We ensure full compliance with international codes, pressure rating charts, weight tolerances, and bolt-hole patterns. Every flange is manufactured with tight dimensional control, high-grade materials, and surface finishes suitable for spiral wound gaskets or RTJ rings, based on your specifications.
Our production is backed by comprehensive documentation, EN 10204 3.1 / 3.2 certification, and NACE MR0175 compliance for sour service applications.
For complete technical details, including dimensions, pressure rating classes, weight charts, sizes, tolerances, and material specifications of our API 605 Standard Flanges, please download the full Catalog PDF below.
Specification | Details |
---|---|
Standard | API 6A |
Flange Types | API 605 (ASME B16.47 Series A) |
Pressure Ratings | Weld Neck Flange, Blind Flange |
Size Range | 26″ to 60″ NB (DN 650 to DN 1500) |
Pressure Ratings | Class 150, 300, 400, 600, 900 |
Face Type | Raised Face (RF), Ring Type Joint (RTJ) |
Drilling Templates | As per ASME B16.47 Series A bolt-hole pattern |
Dimensional Tolerances | Conforming to ASME B16.47 Series A specifications |
Surface Finish | Stock finish (3.2–6.3 µm), Spiral Serrated, Smooth Face |
Marking | According to ASME B16.47 Series A – includes class, size, heat number, and material grade |
Coating & Protection | Black Paint, Rust Preventive Oil, Galvanized |
Applications | Oil & Gas, Refineries, Petrochemical Plants, Offshore, Power Generation, Marine Piping Systems |
Origin | Made in India (by Nutech Overseas) |
Export Network | USA, Europe, and Middle East |
Material Category | API 605 Flange Grades |
---|---|
Stainless Steel API 605 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 API 605 Flange | ASTM A182 F51 / F52 / F53 / F54 / F55 / F57 / F59 / F60 / F61, UNS S31803 / S32205 |
Super Duplex Steel API 605 Flange | ASTM A182 F53 / F55 / F57 / F59 / F60 / F61, UNS S32750 / S32760 |
Carbon Steel API 605 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 API 605 Flange | ASTM A182 F5 / F9 / F11 / F12 / F22 / F91, AISI 4130 / 4140 |
Nickel Alloy API 605 Flange | Nickel 200 / 201, ASTM B564 |
Monel API 605 Flange | Monel 400 (UNS N04400), Monel K500 (UNS N05500), ASTM B564 |
Inconel API 605 Flange | Inconel 600 / 601 / 625 / 690 / 718 / 783 / X750, ASTM B564 |
Incoloy API 605 Flange | Incoloy 800 / 800H / 800HT (UNS N08800), Incoloy 825 (UNS N08825), Incoloy 925, ASTM B564 |
Hastelloy API 605 Flange | Hastelloy C276 (UNS N10276), C22 (UNS N06022), C4, C2000, B2, B3, X, ASTM B564 |
Alloy 20 API 605 Flange | Alloy 20 / 20Cb-3, Carpenter® 20, ASTM B462 |
254 SMO API 605 Flange | SMO 254 / 6Mo, UNS S31254, DIN 1.4547, ASTM A182 |
Copper Nickel API 605 Flange | Copper Nickel 90/10 (C70600), 70/30 (C71500), UNS C71640, ASTM B61 / B62 / B151 / B152 |
Copper API 605 Flange | TP1, TP2, T1, T2, C10100–C12300, C14200–C17200, C21000–C71520, including C10930, C11000, C11400, C12000, C12200, C26000, C28000, C33000, C44300, C70600, etc. |
Brass API 605 Flange | Grades 3602, 2604, H59, H62, etc. |
Aluminium API 605 Flange | Aluminium Grades 5052, 6061, 6063, 2017, 7075, etc. |
Titanium API 605 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 |
API 605 was a standard issued by the American Petroleum Institute for large-diameter steel flanges, primarily covering sizes from 26″ to 60″ NB in pressure classes ranging from Class 150 to Class 900. It was commonly used in oil, gas, and petrochemical pipelines requiring high-integrity flange connections.
However, the API 605 standard has been officially withdrawn, and its scope has been absorbed into ASME B16.47 Series A, which now governs these dimensions, tolerances, and pressure ratings.
Key Points of Transition:
If your specifications mention API 605, you should source flanges compliant with ASME B16.47 Series A for full compatibility and code compliance.
API 605 flanges — now governed by ASME B16.47 Series A — are specifically designed to handle the mechanical and sealing challenges of large-diameter piping (from 26″ to 60″ NB), commonly found in high-capacity, high-pressure pipeline networks.
Key reasons for their preference:
This makes them a top choice in oil & gas terminals, refinery header lines, seawater intake pipelines, and offshore riser systems.
Installing large-diameter flanges like API 605 / ASME B16.47 Series A requires proper planning, equipment, and technical oversight due to their heavy weight and critical sealing role in high-pressure systems.
Important installation considerations include:
Correct installation ensures leak-proof operation, joint longevity, and safety compliance in critical service environments.
API 605 flanges (now ASME B16.47 Series A) are available in a wide range of materials and surface protection options to match the demanding requirements of various industries such as oil & gas, offshore, and chemical processing.
Common Materials Used:
Typical Surface Coatings:
Selecting the right material and protective finish depends on pressure rating, fluid media, operating temperature, and project location.
At Nutech Overseas, we are a trusted global supplier of API 605 (ASME B16.47 Series A) large-diameter flanges, catering to a wide range of industries and EPC contractors around the world.
Our export network spans across:
With a reputation for on-time delivery, strict quality control, and technical compliance, we ensure our flanges meet international codes and client-specific requirements. All export consignments are supported by full inspection documents, MTCs, test reports, and global shipping support.
Whether for offshore, refinery, petrochemical, or pipeline projects — We delivers reliable flange solutions across the globe.