Quality, MTC, TPI & IBR — Documentation Standards

How to read a Mill Test Certificate (MTC)

An MTC is a single-page (sometimes two-page) document issued by the manufacturing mill listing the heat number, dimensional checks, chemical composition, and mechanical test results for the heat from which your pipes were rolled. EN 10204 defines four MTC types: 2.1, 2.2, 3.1, 3.2.

Type 3.1 is the standard B2B document — the mill certifies the values were measured on the actual heat by their independent quality department. Type 3.2 adds a third-party countersignature (typically SGS, BV, or Lloyds), required for IBR boiler service and oil & gas line pipe.

Reading order: heat number → grade → dimensional checks (OD, WT, length) → chemical composition (C, Si, Mn, P, S, plus Cr/Mo/Ni for alloy grades) → mechanical (yield, tensile, elongation, hardness) → hydro-test pressure → flattening / flaring as applicable → dispatch quantity.

When to specify TPI

• IBR boiler service — TPI by an IBR-recognised authority is mandatory
• Oil & gas line pipe (API 5L PSL 2) — TPI is contractually standard
• Public-sector tenders (railways, defence, refineries) — usually mandated
• Repeat critical-application orders — TPI catches mill-side drift
• First-order from a new mill or grade — adds buyer-side confidence

IBR Form III-C — what it certifies

The Indian Boiler Regulations, 1950 require that any tube intended for service in a boiler above the prescribed pressure threshold (>1 kg/cm²) carry a Form III-C certificate. The certificate names the manufacturer, the heat, the grade, the dimensional and mechanical results, and is signed by an Inspecting Authority recognised by the Central Boilers Board.

Buyers should ask for IBR Form III-C at the time of quoting, not at the time of dispatch — adding it post-hoc is impossible. The certificate adds 5-10% to the per-MT cost and 5-10 days to the lead time depending on the IA's availability.