IBR Fittings · Guide
IBR Form IV (Part D) – formerly Form III-C – Guide for Steam-Pipe Fittings (IBR 2026)
IBR Form IV (Part D), the certificate formerly called Form III-C, is the IBR certificate of manufacture and test that lets an elbow, tee, reducer or flange go into a steam line in India. This guide explains what changed on 1 October 2026, what the certificate covers, when it applies and what to check before you order.
What changed on 1 October 2026
- ✓ The Boilers Act, 2025 (Act 12 of 2025) replaced the Indian Boilers Act, 1923, with effect from 1 May 2025.
- ✓ The Indian Boiler Regulations, 2026 (IBR 2026), made under section 40 of the Boilers Act, 2025 “in supersession of the Indian Boiler Regulations, 1950”, came into force on publication in the Gazette of India on 1 October 2026 (notification F. No. P-30014/3/2021-Boilers dated 7 August 2026, Central Boilers Board).
- ✓ Regulation 12: a certificate of manufacture and test in Form IV (Part D), signed by the maker and the Inspecting Authority, in respect of boiler mountings and steam-pipe fittings during manufacture. This replaces the old Form III-C. A photocopy of Form IV (Part D) is accepted if endorsed by the manufacturer or by the Inspecting Authority who signed the original.
- ✓ Related certificates: pipes in Form IV (Part B), formerly Form III-A (regulation 10); tubes in Form IV (Part C) (regulation 11); castings in Form IV (Part E) (regulation 13).
- ✓ Things done under IBR 1950 before the supersession are saved, so certificates and approvals issued under the old regulations before 1 October 2026 are not undone by the change.
Source: Gazette of India, Extraordinary, No. 596, 1 October 2026 (PDF).
As of October 2026 — confirm current procedure with your state Chief Inspector of Boilers.
What Form IV (Part D) is
Form IV (Part D) is the certificate of manufacture and test in respect of boiler mountings and steam-pipe fittings under regulation 12 of the Indian Boiler Regulations, 2026 (IBR 2026), which replaced IBR 1950 on 1 October 2026, under the Boilers Act, 2025. It is the certificate formerly called Form III-C under IBR 1950. As before, the fittings are inspected during manufacture, and the certificate is signed by the maker and by the Inspecting Authority. Without it, a fitting cannot legally be installed in an IBR steam line in India.
The old Form III-C recorded the part name and quantity, serial and drawing numbers, the maker and the customer, the design pressure and temperature, and the metal temperatures the parts are designed for. In practice the certificate is read together with the material test certificate, linked by heat number. Check the exact fields of Form IV (Part D) against the form published with IBR 2026.
When IBR applies to a pipe line
Under the Boilers Act, 1923, as amended in 2007, a steam-pipe was covered when the steam pressure exceeded 3.5 kg/cm² above atmospheric pressure, or when the pipe exceeded 254 mm internal diameter and the steam pressure exceeded 1 kg/cm² above atmospheric pressure; the fittings connected to such a pipe were covered too. The 1923 Act has been replaced by the Boilers Act, 2025, so confirm the current definition of “steam-pipe” under the 2025 Act with your state Chief Inspector of Boilers before deciding a line is outside IBR.
The other IBR certificates you may meet
| IBR 2026 form | Covers | Former IBR 1950 form |
|---|---|---|
| Form IV (Part B) – reg. 10 | Pipes | Form III-A |
| Form IV (Part C) – reg. 11 | Tubes | Form III-B |
| Form IV (Part D) – reg. 12 | Boiler mountings and steam-pipe fittings: elbows, tees, reducers, caps, flanges | Form III-C |
| Form IV (Part E) – reg. 13 | Castings | Form III-F |
Under IBR 1950, forgings were certified in Form III-G. For forgings and any other component not listed above, confirm the applicable IBR 2026 form with the state boiler inspectorate for your project.
Imported fittings
Fittings made outside India for an IBR line need a certificate endorsed by an inspecting authority recognised under the regulations, confirming that the parts meet IBR. Agree who will inspect and endorse before the order is placed. Our article on IBR certification for imported vs Indian-made fittings compares the two routes for EPCs supplying Indian projects.
What to check before you order
- ✓ A current IBR approval for the manufacturer, issued through a state boiler inspectorate, with its validity date
- ✓ Sample Form IV (Part D) certificates (or, for orders before 1 October 2026, Form III-C) from a comparable order, with heat numbers that trace back to the material test certificates
- ✓ Which Inspecting Authority will inspect during manufacture and sign the certificate, and when
- ✓ If you receive a photocopy of Form IV (Part D), that it is endorsed by the manufacturer or by the Inspecting Authority who signed the original
- ✓ For fabricated tees, laterals and reducers, welding procedures qualified to the applicable IBR clauses
How we supply IBR fittings
Our Faridabad works holds IBR approval (Chief Inspector of Boilers, Haryana, memo 187, 2020), and IBR consignments ship with the certificate of manufacture and test required by the regulations in force — Form IV (Part D) for orders made under IBR 2026 — alongside EN 10204 3.1 / 3.2 material certificates and heat-number traceability. Grades include WPB, WP11, WP22, WP91 and WP92; see our IBR grades list and fitting types, product range and quality and approvals.
Sources
- ✓ Indian Boiler Regulations, 2026 – Gazette of India, Extraordinary, No. 596, 1 October 2026
- ✓ Boilers Act, 1923 (India Code, as amended) – historical; replaced by the Boilers Act, 2025
- ✓ Form III-C template (IBR 1950, historical), Directorate of Boilers, West Bengal
- ✓ IBR certificates and forms index, Directorate of Steam Boilers, Maharashtra
- ✓ Indian Boiler Regulation inspection, TÜV SÜD
Frequently Asked Questions
What replaced IBR Form III-C?
Form IV (Part D). The Indian Boiler Regulations, 2026 (IBR 2026), which replaced IBR 1950 on 1 October 2026 under the Boilers Act, 2025, provide in regulation 12 for a certificate of manufacture and test in Form IV (Part D) for boiler mountings and steam-pipe fittings during manufacture, signed by the maker and the Inspecting Authority. It takes the place of the certificate formerly called Form III-C.
Which form covers pipes and which covers fittings?
Under IBR 2026, pipes are certified in Form IV (Part B), formerly Form III-A; tubes in Form IV (Part C); boiler mountings and steam-pipe fittings, such as buttweld elbows, tees, reducers and flanges, in Form IV (Part D), formerly Form III-C; and castings in Form IV (Part E).
Do you supply Form IV (Part D) with your fittings?
Yes. IBR consignments from our Faridabad works ship with the certificate of manufacture and test required by the regulations in force: Form IV (Part D) for orders made under IBR 2026, together with EN 10204 3.1 or 3.2 material certificates.