OEM manufacturer Indian Boiler Regulations, 2026 · ASME B16.5 · ASME B16.47
IBR Approved Flanges for Boiler & Steam Piping
IBR flanges are flanges for boiler and steam piping in India, manufactured, inspected and certified under the Indian Boiler Regulations. Teshi Group is IBR approved and manufactures IBR flanges to ASME B16.5 and B16.47 in carbon and alloy steels.
Also called: IBR flanges, IBR certified flanges, Form III-C flanges, boiler flanges, IBR steam flanges
What are IBR Approved Flanges?
Boilers, steam pipes and their mountings and fittings in India are governed by the Boilers Act, 2025, in force from 1 May 2025, and the Indian Boiler Regulations, 2026, in force from 1 October 2026, which replaced the Indian Boiler Regulations, 1950. Flanges for IBR steam and feed piping must be made from acceptable material, with manufacture and testing inspected by an Inspecting Authority. The maker and the Inspecting Authority then sign the certificate of manufacture and test, known as Form III-C under the 1950 regulations.
Key features
- Certificate of manufacture and test countersigned by the Inspecting Authority
- Inspection witnessed by the Inspecting Authority
- Raw material traceable to mill certificates acceptable under IBR
- Heat number and identification marking on each flange
- Supplied to ASME B16.5 and B16.47 in carbon and alloy steel
Specification
| Supply | OEM manufacturer — Teshi Group, India |
|---|---|
| Regulation | Indian Boiler Regulations, 2026 (Boilers Act, 2025); formerly IBR 1950, Form III-C |
| Dimensional standard | ASME B16.5 (NPS ½″–24″); ASME B16.47 (NPS 26″–60″) |
| Flange types | Weld neck, slip-on, socket weld, blind, long weld neck |
| Pressure class | Class 150–2500 |
| Materials — carbon steel | ASTM A105 / A105N; ASTM A181 Cl 60, Cl 70; ASTM A266 Gr 2, Gr 4 (large forgings) |
| Materials — high-yield carbon steel | ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 (MSS SP-44 grades F52–F70) |
| Materials — low-temperature carbon steel | ASTM A350 LF1, LF2 Cl 1, LF2 Cl 2, LF3, LF6, LF9 |
| Materials — alloy steel (Cr-Mo) | ASTM A182 F1, F2, F5, F5a, F9, F11 Cl 1 / 2 / 3, F12 Cl 1 / 2, F21, F22 Cl 1 / 3, F22V, F91, F92, F911; ASTM A336 F11, F22 (large forgings) |
| Materials — stainless steel | ASTM A182 F304, F304L, F304H, F304LN, F309H, F310, F316, F316L, F316H, F316LN, F316Ti, F317, F317L, F321, F321H, F347, F347H, F348 |
| Materials — 904L and 6Mo | 904L (ASTM A182 F904L, UNS N08904); 254 SMO / 6Mo (ASTM A182 F44, UNS S31254); AL-6XN (ASTM A182 F62, UNS N08367) |
| Materials — duplex stainless steel | ASTM A182 F51 (UNS S31803), F60 (UNS S32205, 2205) |
| Materials — super duplex stainless steel | ASTM A182 F53 (UNS S32750, 2507), F55 (UNS S32760), F61 (UNS S32550) |
| Materials — nickel alloys | ASTM B564 / B160 / B462: Nickel 200 / 201 (N02200 / N02201), Monel 400 (N04400), Monel K-500 (N05500), Inconel 600 (N06600), Inconel 625 (N06625), Inconel 718 (N07718), Incoloy 800 / 800H / 800HT (N08800 / N08810 / N08811), Incoloy 825 (N08825), Hastelloy C276 (N10276), Hastelloy C22 (N06022), Hastelloy B2 / B3 (N10665 / N10675), Alloy 20 (N08020) |
| Materials — titanium | ASTM B381 Grade F1, F2, F5 (Ti-6Al-4V), F7, F12 |
| Materials — copper-nickel | Cu-Ni 90/10 (UNS C70600) and 70/30 (UNS C71500), ASTM B151 bar; flanges to ASME B16.5 or EEMUA 145 |
| Grade availability | Every grade listed is made or supplied against order, with EN 10204 3.1 certificates (3.2 / third-party inspection when specified) and PMI on alloy, stainless, duplex and nickel grades. |
| Testing | Chemical and mechanical tests, dimensional inspection, hardness; witnessed by the Inspecting Authority |
| Documents | IBR certificate of manufacture and test; EN 10204 3.1 mill test certificate; dimensional inspection report |
Applications
- Boiler feed water and main steam piping
- HRSG and waste heat boiler piping
- Steam distribution in process plants
- Captive power plants and cogeneration
- Sugar, paper, textile and food plant steam lines
Technical data sheets
Dimensions & weights
FAQ
IBR Approved Flanges: common questions
What is Form III-C?
Under the Indian Boiler Regulations, 1950, Form III-C was the Certificate of Manufacture and Test of Boiler Mountings and Fittings, signed by the maker and the Inspecting Authority. Buyers still use the term; certificates are now issued in the form prescribed under the 2026 Regulations.
Did the IBR change in 2025–2026?
Yes. The Boilers Act, 2025 replaced the 1923 Act from 1 May 2025, and the Indian Boiler Regulations, 2026, published on 1 October 2026, replaced IBR 1950. IBR approval and Inspecting Authority certification continue under the new framework.
When do I need IBR flanges?
When the flanges are in a boiler or in steam or feed piping within the scope of the Boilers Act, as defined by the regulations and your plant's boiler inspectorate. Utility steam lines outside that scope may not need IBR certification.
Which materials are used for IBR flanges?
ASTM A105 for carbon steel service, and ASTM A182 F11, F22 and F91 for higher-temperature steam. The material must have mill certificates acceptable under IBR.
Is Teshi Group IBR approved?
Yes. Teshi Group is ISO 9001:2015 certified and IBR approved, and supplies flanges with the IBR certificate of manufacture and test, issued after Inspecting Authority inspection, when the purchase order specifies IBR service.
Need a size or grade not listed here?
Our engineering team manufactures against your drawing or datasheet, with dimensional sign-off before dispatch.
Send us your specificationTraceability
From mill heat to your site
- 01
Approved mill material
Received against the mill certificate; heat number registered.
- 02
Forging & machining
Heat number carried through every stage in our Indian works.
- 03
PMI, dimensional & NDT
Every lot inspected to the governing standard; TPI witness on request.
- 04
Stamped & certified dispatch
Hard-stamped pieces with EN 10204 3.1 / 3.2 certificates.
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