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    Flanges

    Weld neck, blind and slip-on flanges in Duplex F51, Super Duplex F53/F55 and 6Mo alloys — 1/2" to 48" OD across all pressure classes, ASME B16.5, B16.47 and API 6A.

    Large-diameter duplex weld neck flange with raised face and bolt holes
    Weld neck, blind and slip-on flanges in Duplex, Super Duplex and 6Mo
    EN 10204 3.1 Certified
    ISO 9001 Quality

    Overview

    EMG offers a broad stock program of high-quality weld neck, blind and slip-on flanges in Duplex (F51 / UNS S31803 / S32205), Super Duplex (F53 / UNS S32750, F55 / UNS S32760), and 6% Moly alloys. Available from 1/2 inch up to 48 inch OD in all pressure classes, our flanges are designed to ASME B16.5, ASME B16.47 (Series A and B) and API 6A standards. Every flange in our portfolio meets or exceeds international testing standards including ASTM A182, NORSOK M-630 (D44/D54) and Shell MESC SPE 76-212. All incoming materials undergo in-house quality verification — chemical analysis, ultrasonic examination, hardness testing and dye-penetrant inspection.

    With NORSOK M-650 approved supply routes and a unique stock position, our flanges are trusted across global energy, desalination, and heavy industrial projects — precision-engineered for full compatibility wherever reliability is critical.

    Typical Applications

    • Offshore oil & gas topside and subsea piping
    • Petrochemical processing plants
    • Desalination and seawater service
    • Power generation and steam systems
    • Wellhead and Christmas tree assemblies (API 6A)
    • LNG and chemical plant flanged joints

    Flange Types We Supply

    • Weld neck flanges (WN) — raised face, RTJ and flat face
    • Blind flanges (BL)
    • Slip-on flanges (SO)
    • Socket weld flanges (SW)
    • Threaded flanges (TH)
    • Lap joint flanges and stub ends
    • Long weld neck and orifice flanges
    • Anchor / spectacle blinds and spacer-spades

    Common Materials & Grades

    Duplex F51 — UNS S31803 / S32205Super Duplex F53 — UNS S32750Super Duplex F55 — UNS S327606% Moly UNS S31254 (254 SMO)Nickel Alloy 625 (UNS N06625)Nickel Alloy 825 (UNS N08825)SS 304 / 304L (F304/F304L)SS 316 / 316L (F316/F316L)SS 321 (F321), SS 347 (F347)Low Alloy F11 / F22 / F91Carbon Steel A105

    Standards & Documentation

    • ASME B16.5 — pipe flanges and flanged fittings (1/2" – 24")
    • ASME B16.47 Series A & B — large diameter flanges (26" – 60")
    • API 6A — wellhead and Christmas tree equipment
    • ASTM A182 — forged or rolled alloy and stainless flanges
    • NORSOK M-630 (MDS D44/D54) and M-650 qualified supply
    • Shell MESC SPE 76-212 compliance
    • EN 10204 3.1 / 3.2 MTRs with full heat-number traceability
    • In-house PMI, hardness, ferrite, UT and DP testing

    RELATED RESOURCES

    PipesFittingsStud BoltsNORSOK M-630 / M-650API StandardsDuplex & Super Duplex
    FREQUENTLY ASKED QUESTIONS

    Technical FAQs

    Which flange grade should I specify for Super Duplex service?

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    For Super Duplex flanges, ASTM A182 F53 (UNS S32750) and F55 (UNS S32760) are the two recognised grades. F55 contains slightly higher chromium and tungsten and is often specified for the most aggressive chloride and CO₂ environments. Both should comply with NORSOK M-630 MDS D54 for North Sea projects.

    What is the largest flange you can supply?

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    Standard flanges are supplied from 1/2 inch to 24 inch under ASME B16.5, and from 26 inch to 60 inch under ASME B16.47. Larger custom flanges are available on a project basis with full forging and machining traceability.

    Do you supply API 6A flanges for wellhead service?

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    Yes. We supply API 6A 6BX and 6B flanges in PSL-3/PSL-4 categories for wellhead and Christmas tree equipment, with full material certification and dimensional reports.

    Are flanges supplied with NORSOK M-630 / M-650 documentation?

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    Yes. Duplex, Super Duplex and 6Mo flanges are supplied with NORSOK M-630 MDS sheets and traceable to NORSOK M-650 qualified manufacturers. Documentation packs include MTRs, dimensional reports, PMI logs and any required NDE records.
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