IBR Approved Pipe Fittings: Grades, Sizes & Form IV (Part D)

What “IBR approved” means for a pipe fitting

In India, an elbow, tee, reducer, cap or flange that goes into a steam or feedwater line covered by the Boilers Act must be made by an IBR-approved manufacturer, inspected during manufacture by an Inspecting Authority, and certified on the prescribed IBR form. A fitting that only carries an ASTM marking and a mill certificate is not enough for an IBR line: the boiler inspector will ask for the IBR certificate that links the part, by heat number, to the inspection carried out during manufacture.

Since 1 October 2026 the governing rules are the Indian Boiler Regulations, 2026 (IBR 2026), published in the Gazette of India, Extraordinary, No. 596, under the Boilers Act, 2025. Regulation 12 provides for a certificate of manufacture and test in Form IV (Part D) for boiler mountings and steam-pipe fittings. It replaces the certificate called Form III-C under IBR 1950. Our Form IV (Part D) guide explains the change in detail.

IBR grades list

The grade is chosen by the boiler or piping designer from the design temperature and pressure of the line. These are the grades we make most often for IBR service; each grade page carries chemistry, mechanical properties, equivalents and testing.

For oil, gas and LNG projects (mostly ASME work for the Gulf rather than IBR) we also make A420 WPL6 low-temperature carbon steel, duplex 2205 and super duplex 2507. If you need any of these on an IBR line, state it on the enquiry and we will confirm the certification route before quoting.

IBR fitting types

• Buttweld elbows — 45°, 90° and 180°, long and short radius
• Buttweld tees — equal and reducing
• Reducers — concentric and eccentric
• Pipe caps — buttweld end closures
• Lap joint stub ends — for lap joint flange assemblies
• Laterals and crosses — equal and reducing
• Flanges — weld neck, slip-on, blind, socket weld, ring type joint and lap joint, forged in ASTM A105 and A182 grades

Sizes, schedules and standards

• ✓ Seamless fittings up to 24" NB; welded (WX) fittings up to 48" NB and above
• ✓ Wall thickness from SCH 20 through SCH 160 and XXS, or to a specified wall thickness
• ✓ Dimensions to ASME B16.9, including short radius elbows; weld end bevels to ASME B16.25
• ✓ Flanges to ASME B16.5 and ASME B16.47, Classes 150 to 2500

Delivery depends on grade, size and stock position. Alloy steel, large-diameter and high-schedule fittings are made to order, and the delivery date is confirmed at quotation stage, taking the IBR inspection visits into account.

Documents supplied with an IBR order

• ✓ Form IV (Part D) certificate of manufacture and test, signed by the maker and the Inspecting Authority (Form III-C for orders certified under IBR 1950 before 1 October 2026)
• ✓ EN 10204 3.1 material test certificate as standard; EN 10204 3.2 on request
• ✓ Heat-number marking on every piece, traceable from the raw material to the certificates
• ✓ Dimensional inspection report and certificate of conformance; heat-treatment records for alloy grades

How to write the enquiry

A complete enquiry gets a faster and more accurate quotation. For each line item, state:

• ✓ Fitting type and standard, for example “90° LR elbow, ASME B16.9”
• ✓ Grade, for example “ASTM A234 WP11 Class 1”, and seamless or welded
• ✓ Size (NB) and schedule or wall thickness, and the quantity
• ✓ “IBR required — Form IV (Part D)”, and the state where the boiler is registered if known
• ✓ Whether you need EN 10204 3.2 and which third-party agency you prefer

Third-party inspection for EN 10204 3.2 can be arranged with TÜV, Bureau Veritas, SGS, DNV, Lloyd’s Register or the buyer’s own inspector. This is separate from the IBR inspection, which is carried out by the Inspecting Authority that signs Form IV (Part D).

Buying from the Gulf for an Indian project

EPC contractors in Saudi Arabia, the UAE, Oman and Qatar often procure for power and process plants in India. Fittings made in India under IBR inspection carry Form IV (Part D) issued at the works, which avoids the extra endorsement step needed for imported parts. See imported vs Indian-made IBR fittings, and our pages for Saudi Arabia, the UAE, Oman and Qatar.

Related reading: understanding IBR compliance · carbon vs alloy vs stainless fittings · ASME B16.9 inspection checklist · buying fittings from India for Gulf projects · IBR fittings for sugar and distillery cogeneration boilers · WP91 fittings for HRSGs · full product range.