Manufacturing and Inspection of Liquid CO2 Trailers
- Publisher
- European Industrial Gases Association
- Document
- TB 64/26
- Edition
- Technical Bulletin (2026)
- Document language
- English
EIGA Technical Bulletin TB 64/26, issued in July 2026 by working group WG-6, addresses a specific manufacturing trend in liquid carbon dioxide road tankers. These tankers are normally non-vacuum vessels insulated with foam, built under ADR 6.8.2.6.1 which refers to EN 14398-2 for large transportable non-vacuum insulated cryogenic vessels.
The bulletin was written because austenitic-ferritic duplex stainless steel is increasingly used for this equipment, and duplex behaves differently from the austenitic grades the industry is used to.
What the document covers
- Duplex stainless steel has roughly double the yield strength of classical austenitic grades, which allows thinner plate, lower tare weight and higher payload.
- Duplex also offers attractive corrosion behaviour and a good cost to property ratio.
- Welding duplex is not difficult but it is different: weld properties depend strongly on heat input.
- Rapid cooling from high temperature can leave high ferrite levels in the weld metal and the adjacent base metal.
- Slow cooling can cause loss of ductility in the heat affected zone. Both effects can create brittle areas on the vessel and the weld.
- Cold forming of dished ends requires greater working forces because of the high proof strength of the material.
What it means for equipment
This is the kind of document that separates a tanker that looks the same on paper from one that will behave in service. If you are evaluating a CO2 semi-trailer, duplex construction is a legitimate way to gain payload, but the welding procedure and the ferrite control behind it are what make that gain safe.
When you review an offer or inspect a used unit, the questions this bulletin raises are the right ones: what material, what welding procedure qualification, and what records exist for heat input and forming.