Small industrial boilers under IBR 2026
Under IBR 2026 a small industrial boiler is a shell boiler up to 7 kg/cm² (g) holding more than 25 and up to 500 litres, or a coil, once-through or water tube boiler up to 12 kg/cm² (g) and 150 litres. Its certificate of manufacture and test is Form XXII, which was Form XVII under IBR 1950.
Pujan Motiwala · Checked against the Gazette on · IBR 2026, in force from 1 October 2026
What counts as a small industrial boiler under IBR 2026?
A small industrial boiler, under regulation 546 of IBR 2026, is one of two kinds. A shell type boiler working up to 7 kg/cm² (g), with a volumetric capacity of more than 25 litres and up to 500 litres, measured from the feed check valve to the main steam stop valve. Or a coil type, once-through or water tube boiler working up to 12 kg/cm² (g), with a capacity of up to 150 litres. A boiler combining both kinds is held to 7 kg/cm² (g) and 500 litres in total.
Which stages are inspected for a small shell boiler?
An Inspecting Authority inspects a small industrial boiler during construction (regulation 550). For a shell type boiler, regulation 551 sets four stages: material identification and inspection; each component after welding and drilling; assembly of the boiler; and the hydraulic test. A welded boiler is tested at twice its design pressure, and the maker provides a test coupon for root and face bend tests.
Which certificate does a small industrial boiler need?
A small industrial boiler's certificate of manufacture and test is Form XXII (regulation 555(2)). Under IBR 1950 this was Form XVII, which also covered small solar boilers; they now have their own Form XXIII. If the boiler's plate is too small to stamp every detail, the certificate carries them, but the name, works number and year of make are always stamped or shown on the boiler (regulation 553(2)).
Which plates can a small industrial boiler use, and is a steel maker's certificate needed?
A small industrial boiler's plates are IS 2062 fully killed steel or equivalent, at least 6 mm thick for the shell and heads, and at least 8 mm where heads serve as tube sheets for rolled-in tubes (regulation 548(2)(a)). The steel maker's certificate in Form V Part A is not required for IS 2062 plates, provided every other certification requirement is met (regulation 548(2)(b)).
How is a small industrial boiler's registry number marked?
A small industrial boiler's registry number carries an "S" prefix below the state's letters, for example "GT" over "S-" and the number for a boiler registered in Gujarat (regulation 301(1)(c)).
Quoted from the regulations (13)
“A shell type boiler generating steam for use external to itself under pressure up to 7 kg/cm2 (g) and having a volumetric capacity exceeding 25 litres”
IBR 2026, regulation 546(a)
“but not exceeding 500 litres including the volumetric capacity of all pressure parts being heated from the same heating source and connected to the boiler”
IBR 2026, regulation 546(a)
“The limitation of pressure shall be 12 kg/cm2 (g), and”
IBR 2026, regulation 546(b)
“The capacity shall not be exceeding 150 litres;”
IBR 2026, regulation 546(b)
“The small industrial boilers shall be subjected to inspection during construction by an Inspecting Authority”
IBR 2026, regulation 550
“material identification and inspection;”
IBR 2026, regulation 551(1)
“the hydraulic test pressure shall be equal to two times the design pressure of the boiler.”
IBR 2026, regulation 551(2)
“A test coupon shall be provided by the maker for conducting root and face bend tests.”
IBR 2026, regulation 551(3)
“but in all cases, name, works number and the year of the make shall be stamped or exhibited on the boiler.”
IBR 2026, regulation 553(2)
“The certificate of manufacture and test for small industrial boilers shall be issued in Form-XXII.”
IBR 2026, regulation 555(2)
“Steel plates used in the construction of the boilers shall be of IS: 2062 fully killed or equivalent and the plate for shell and heads shall be not less than 6 mm in thickness”
IBR 2026, regulation 548(2)(a)
“The steel maker certificate provided in Part A of Form V is not required for steel plates of IS: 2062 from the steel maker provided all other certification requirements as specified in applicable regulations are complied with.”
IBR 2026, regulation 548(2)(b)
“In the case of registration of small industrial boilers, the letter “S” shall be added as a prefixed to the registration number”
IBR 2026, regulation 301(1)(c)
See a boiler's IBR folder produced from its material certificates, with a sample company.
Built for a boiler manufacturer: ERP for boiler manufacturers · how the folder is produced
Official sources
- Indian Boiler Regulations, 2026 (Gazette of India, Extraordinary, No. 596). Central Boilers Board, Department for Promotion of Industry and Internal Trade, October 1, 2026.
What this page is not
A guide written by Ahrom Labs from the Gazette text; not legal advice. The Gazette governs wherever this page differs from it, and a state's Chief Inspector of Boilers may set procedures of their own. Last updated .
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