Chemical & Pharmaceutical

In chemical and pharmaceutical work, stainless is not chosen for appearance — it is chosen for corrosion resistance, cleanability and traceability. All three have to be documented, not asserted.

What we supply

Why 316L, almost always

Chemical plants deal in chlorides: chlorinated water, hydrochloric acid traces, hypochlorite cleaning, brine cooling. 304 will pit under those conditions. The 2–3% molybdenum in 316L is what resists pitting and crevice corrosion, and the low carbon (≤0.03%) prevents sensitisation in the heat-affected zone of welds — which matters because vessels and pipework are welded everywhere and cannot be annealed afterwards.

The paperwork is part of the product

• EN 10204 3.1 mill test certificate — issued for the actual heat, with chemistry and mechanicals. Not a generic spec sheet.
• Heat number traceability — on the plate, on the certificate, and on the packing list. Auditors ask for the link.
• Surface roughness report if Ra is specified — measured, not assumed.
• PMI (positive material identification) on request, for critical service.

What to specify

• Ra target. Hygienic service is often Ra ≤ 0.8 µm; aseptic work may call for electropolishing.
• Weld preparation. Say whether edges need to be machined or bevelled before shipment.
• Test requirements. Hydrostatic, dye penetrant, radiography — agree before the order, not after.
• Documentation language. Certificates in English with the heat number legible.

Mistakes we see

Accepting a 2.2 certificate. A 2.2 is a statement of compliance, not test results from the heat. For pressure equipment it is usually not acceptable.

Ordering 304L "to save cost" for a chlorinated duty. The saving is real; the pitting comes later, usually at a weld.

Forgetting passivation. Welded 316L has a depleted surface at the weld. Without passivation, that is exactly where corrosion starts.

Related products

• Sheet & plate — vessel shells and heads
• Pipe & tube — process and CIP lines
• Coil & strip — heat exchanger plates

Send the duty description and the documentation requirements — we will quote with the MTC 3.1 scope confirmed in writing.