SS 347H Tube Supplier in India — Boiler Grade Niobium Stabilized

Both SS 347H and SS 321H are high-carbon stabilized grades for creep service, but they use different stabilizing elements. SS 347H uses niobium (Nb ≥ 10×C%) while SS 321H uses titanium (Ti ≥ 5×C%). At temperatures above 600°C, SS 347H generally shows superior creep rupture strength compared to 321H. Additionally, niobium carbides are more thermodynamically stable at extreme temperatures and niobium transfers well across the welding arc, ensuring weld metal retains stabilization. For critical boiler and superheater applications above 600°C, many specifications prefer SS 347H over 321H.

SS 347H boiler and superheater tubes are covered under ASTM A213 / ASME SA213 Grade TP347H — 'Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes.' Key requirements include: solution annealing at 1040-1120°C, carbon range 0.04-0.10%, niobium content Nb ≥ 10×C%, hardness ≤ 90 HRB, grain size ASTM 7 or coarser, and mandatory hydrostatic or eddy current testing. The material must also pass intergranular corrosion testing per ASTM A262 Practice E.

Yes, Creative Metal Industries stocks IBR (Indian Boiler Regulation) certified SS 347H tubes with complete Form III-C documentation. IBR certification is mandatory for tubes installed in boilers and pressure vessels in India operating above specified pressure and temperature limits. Our IBR stock comes from approved mills (Sandvik, Ratnamani, Sumitomo) with full documentation package: IBR Form III-C, MTC EN 10204 3.1, chemical analysis, mechanical test reports, hydrostatic test certificate, IGC test report, and non-destructive examination records.

Creative Metal Industries sources SS 347H tubes from globally recognized mills: Sandvik (Sweden) — the benchmark for critical boiler and superheater tubes; Ratnamani (India) — ASME/IBR certified, excellent quality and competitive pricing; Sumitomo (Japan) — premium quality for critical high-temperature applications; Tubacex (Spain) — PED certified European manufacturer; and selected Korean and Chinese ASME-certified mills for cost-effective applications. For critical superheater and reformer tube applications, we recommend Sandvik or Sumitomo. Ratnamani offers excellent value for standard boiler tube requirements.

SS 347H tubes are used in the most demanding high-temperature applications: superheater tubes in thermal and nuclear power plants (steam temperatures 540-620°C), catalytic reformer tubes in refineries, ethylene cracker radiant and convection section tubes, steam methane reformer (SMR) outlet pigtails, waste heat boiler tubes in ammonia and methanol plants, and HRSG superheater sections in combined cycle plants. The niobium stabilization with high carbon provides the creep strength needed for long-term service at elevated temperatures under sustained pressure.

SS 347H seamless tube prices in India typically range from Rs 500-1100 per kg depending on OD, wall thickness, mill source, and order quantity. SS 347H carries a premium over standard 347 due to the controlled carbon range and additional testing requirements. IBR certified tubes command a 5-10% premium over non-IBR material. Sandvik tubes are typically 30-40% more expensive than Ratnamani or imported options. For competitive quotations, contact Creative Metal Industries at +91 99982 80619 — we offer direct mill pricing without intermediary markup.