EN 10253-2 Type B buttweld fittings for the full range of process industries — from refinery and power generation to pharmaceutical and offshore. Correct material grade, correct certification, on every order.
Refinery and upstream applications span the full CrMo grade ladder — from P11 fractionation headers to P91 HRSG superheater loops, and P22/P5 hydroprocessing circuits operating under elevated H₂ partial pressure. Upstream sour gas service (H₂S) requires NACE MR0175 hardness compliance; we supply duplex, super duplex, and Alloy 825 fittings with per-heat hardness certificates.
From sub-critical coal plant reheaters (P11, P22) to supercritical and ultra-supercritical steam headers (P91, P92), the power sector demands the most rigorous CrMo fitting quality. All CrMo fittings are supplied with PWHT time-temperature charts and hardness results on the EN 10204 3.1 certificate. Third-party TÜV or Lloyd's countersignature (EN 10204 3.2) is available for critical circuits.
Process chemistry dictates material selection. Sulphuric acid (H₂SO₄) and phosphoric acid (H₃PO₄) service requires 904L or Alloy 825 for their combined molybdenum and copper content. Hydrochloric acid and chlorinated solvents demand Hastelloy C-276 or C-22. Mixed oxidising/reducing environments favour C-22's higher chromium content. Hydrofluoric acid service is exclusive to Monel 400.
WFI (Water for Injection) and clean steam piping demands low carbon 316L (1.4404) or 1.4435 with controlled delta ferrite number (FN ≤1.0 typically) and Ra ≤0.8 µm bore surface finish. We supply delta ferrite reports per EN 10204 3.1 and surface finish (Ra) certificates per fitting on request. Compliant with ISPE Baseline Guide Vol. 4 and EU Annex 1 requirements.
Seawater and offshore atmosphere combine chloride pitting and crevice corrosion risks with demanding structural requirements. Duplex 2205 (1.4462) provides 2× the yield strength of 316L with PRE ≥35, meeting NACE MR0175 for sour zones. Super duplex 2507 (1.4410) delivers PRE ≥40 for deep subsea and concentrated seawater applications. Inconel 625 covers high-strength subsea components where duplex sigma phase risk is a concern above 300°C.
Reverse osmosis (RO) and multi-stage flash (MSF) desalination plants present extreme chloride concentrations that eliminate standard austenitic stainless. Super duplex 2507 (1.4410) and Alloy 825 are the primary grades for high-pressure RO concentrate piping and MSF evaporator headers. Duplex 2205 is suitable for lower-pressure brine circuits. Crevice corrosion in dead legs is the primary failure mode — Type B wall thickness is essential for adequate fitting wall under reduced corrosion allowance.
Above 800°C, standard austenitic stainless steels fail by rapid oxidation scaling. Inconel 601 (2.4851) forms a stable Al₂O₃ scale and resists oxidation to 1200°C, making it the standard for industrial furnace tube headers, carbon black reactor piping, and calcination systems. Where creep strength is the primary requirement at 900–1100°C — gas turbine hot sections and AUSC steam reformers — Inconel 617 (2.4633) with its cobalt solid-solution strengthening takes precedence.
FGD scrubber systems combine dilute H₂SO₄, HCl, and dissolved chlorides in an oxidising atmosphere — one of the most demanding corrosion environments encountered in process engineering. Standard duplex grades are borderline; Hastelloy C-22 (2.4602) is the typical specification for absorber vessels and recirculation piping because its 21% Cr content provides superior resistance to the simultaneous oxidising and reducing attack present in wet scrubbers. C-276 is an alternative where the environment is predominantly reducing.
| Industry | Standard Cert | Frequent Add-ons |
|---|---|---|
| Oil & Gas — refinery | EN 10204 3.1 + PWHT | PMI, NACE hardness, API 941, EN 10204 3.2 (TÜV/BV) |
| Power generation | EN 10204 3.1 + PWHT time-temp | EN 10204 3.2 (Lloyd's/TÜV), Charpy impact |
| Chemical / petrochemical | EN 10204 3.1 | PMI, NACE MR0175, PED CE mark |
| Pharmaceutical / food | EN 10204 3.1 | Delta ferrite (FN), Ra ≤0.8 µm surface finish, PMI |
| Offshore / subsea | EN 10204 3.2 | NACE hardness, Charpy V-notch, DNV/Lloyd's witness |
| Desalination | EN 10204 3.1 | NACE, PMI, PED |
| Industrial furnace / high temp | EN 10204 3.1 | PMI, PWHT |
| FGD | EN 10204 3.1 | PMI (XRF), PED |
Include your service conditions, certification requirements, and delivery port. We will recommend the correct EN grade and certificate package and respond within 24 hours on business days.
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