Tank containers
The 20' tank container
A stainless steel shell in a 20-foot frame. It fits every container slot and may weigh 36,000 kg gross.
The T codes
Which substance may go into which tank is governed by the UN portable tank instruction. The higher the number, the higher the test pressure and shell thickness. T11 is the class of the typical 20' chemical tank.
| Instruction | Min. test pressure (bar) | Min. shell thickness | Bottom openings |
|---|---|---|---|
| T1 – T2 | 1.5 | see 6.7.2.4.2 | allowed |
| T3 – T4 | 2.65 | see 6.7.2.4.2 | allowed |
| T5 | 2.65 | see 6.7.2.4.2 | not allowed |
| T6 – T7 | 4 | see 6.7.2.4.2 | allowed |
| T8 | 4 | see 6.7.2.4.2 | not allowed |
| T9 – T10 | 4 | 6 mm | not allowed |
| T11 – T12 | 6 | see 6.7.2.4.2 | allowed |
| T13 – T14 | 6 | 6 mm | not allowed |
| T15 – T16 | 10 | see 6.7.2.4.2 | allowed |
| T17 – T18 | 10 | 6 mm | allowed |
| T19 | 10 | 6 mm | not allowed |
| T20 | 10 | 8 mm | not allowed |
| T21 – T22 | 10 | 10 mm | not allowed |
Minimum test pressure and minimum shell thickness (reference steel) per ADR 2025, 4.2.5.2.6. A higher instruction may replace a lower one (4.2.5.2.5). T50 covers non-refrigerated liquefied gases, T75 refrigerated liquefied gases.
An ISO tank from the NOBLE fleet
NOBLE publishes this equipment for its ISO tank:
- Full frame for lifting security
- 2.5" BSP high-flow safety relief valve set at 4.4 bar, plus one provision with blank flange
- 1.5" air inlet with stainless ball valve
- 2 × 3" top discharge provision with blank flange
- 3" bottom outlet with butterfly valve
- 50 mm rockwool insulation and 10 m² effective heating area
- Design code ASME VIII Div 1
- Approvals: IMDG, CFR49, RID/ADR, US DoT, UIC, TIR, CSC, TC
What that means: the heating area and insulation make the tank usable for substances that must be kept warm in transit. The approval list decides on which modes and in which countries it may run.
The test cycle
- Initial test before first being placed into service.
- Intermediate test after 2.5 years.
- Periodic test at least every 5 years.
- Tolerance: the test may be carried out up to three months before or after the due date.
What that means: a tank container runs on a fixed calendar. For buyers of used tanks the next test date is therefore one of the first questions.