T13 is the IMDG Code Chapter 6.7 portable tank instruction at 6 bar test pressure with the 6 mm reference-steel shell explicitly required, no bottom outlet, and a normal pressure-relief valve (no frangible disc). T13 sits between T8 (4 bar test, no BO, normal PRV) and T14 (6 bar, no BO, frangible disc). Cargo population: higher-hazard Class 8 corrosives where the IMDG profile demands the no-BO rule and the higher test pressure but not a frangible disc.
What T13 is built for
The IMDG Dangerous Goods List assigns T13 to specific Class 8 PG I/II UN entries that need the higher 6 bar test pressure and the no-bottom-outlet rule, but where the cargo’s reactivity does not warrant a frangible disc. The cargo list is small. In commercial practice many T13-eligible cargoes ship in T14 (where the additional frangible disc is treated as a useful safety margin).
Construction and materials
316L stainless cylinder, 6 mm reference-steel shell. Top discharge through a dip-pipe. Standard PRV at 4 bar with vacuum-relief at minus 0.21 bar.
When T13 is the right choice
T13 is the right tank when IMDG DGL Column 13 specifies T13 for the UN entry. The substitution rule allows T13 cargo to ride T14 through T22.
When T13 is the wrong choice
T13 is the wrong tank for cargoes assigned to T14 (where the frangible disc is mandatory) or T8 (where the lower 4 bar test pressure is sufficient and the operator fleet is larger).