T19 is the IMDG Code Chapter 6.7 portable tank instruction at 10 bar test pressure with 6 mm reference-steel shell, no bottom outlet, and a frangible-disc plus tell-tale-gauge relief regime. The combination places T19 just below T20 (which adds an 8 mm shell) and T22 (10 mm shell) in the Class 6.1 hazard ladder. Cargo population: the highest-hazard Class 6.1 toxics where the cargo’s vapour pressure or operational profile exceeds T14’s 6 bar test pressure but does not require the thicker shell of T20 or T22.
What T19 is built for
The IMDG Dangerous Goods List assigns T19 to specific Class 6.1 UN entries where the cargo profile sits at the highest end of toxicity but doesn’t require the heaviest standard shell. The substitution rule of IMDG 4.2.5.2.5 lets a T19 cargo also ride T20 (8 mm), T21 (10 mm normal PRV), or T22 (10 mm frangible).
Construction and materials
316L stainless cylinder, 6 mm reference-steel shell with the explicit “minimum 6 mm” requirement. ASME U-stamp standard. Top discharge through a dip-pipe with no foot valve at the bottom. Frangible disc plus tell-tale gauge mounted in series with a 4.4 bar PRV.
When T19 is the right choice
T19 is the right tank when IMDG DGL Column 13 specifies T19 for the UN entry. T19 fleet inventory is small; bookings often substitute up to T20 or T22 if those tanks are available at the loading port.
When T19 is the wrong choice
T19 is the wrong tank for cargoes that fit T14 (6 bar test, identical no-BO and frangible-disc profile but lower pressure rating, where the operator fleet is much bigger) or for the heaviest cargoes (bromine, organometallics) that require the 8 or 10 mm shell of T20 / T21 / T22.