T4 PORTABLE TANK INSTRUCTION T4
The general provisions of section 4.2.1 and the requirements of section 6.7.2 shall be met.
Minimum test pressure 2.65 bar
Minimum shell thickness (reference steel) 5 mm for tanks up to 1.80 m diameter and for larger tanks carrying solids of packing group II or III; 6 mm otherwise.
Pressure-relief provisions Normal
Bottom opening provisions 3 shut-off devices required.
Alternatives permitted T5, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16, T17, T18, T19, T20, T21, T22

Special packing provisions:

TP1
The degree of filling prescribed in 4.2.1.9.2 shall not be exceeded.
TP2
The degree of filling prescribed in 4.2.1.9.3 shall not be exceeded.
TP3
The maximum degree of filling (in %) for solids transported above their melting points and for elevated temperature liquids shall be determined in accordance with 4.2.1.9.5.
TP6
To prevent the tank bursting in any event, including fire engulfment, it shall be provided with pressure-relief devices which are adequate in relation to the capacity of the tank and to the nature of the substance transported. The device shall also be compatible with the substance.
TP8
The test pressure for the portable tank may be reduced to 1.5 bar when the flashpoint of the substances transported is greater than 0°C.
TP13
Self-contained breathing apparatus shall be provided when this substance is transported, unless no self-contained breathing apparatus, as required by SOLAS regulation II-2/19 (II-2/54), is on board.
TP24
The portable tank may be fitted with a device located, under maximum filling conditions, in the vapour space of the shell to prevent the build-up of excess pressure due to the slow decomposition of the substance transported. This device shall also prevent an unacceptable amount of leakage of liquid in the case of overturning or entry of foreign matter into the tank. This device shall be approved by the competent authority or its authorized body.
TP28
A portable tank having a minimum test pressure of 2.65 bar may be used if it is shown that a test pressure of 2.65 bar or less is acceptable according to the test pressure definition in 6.7.2.1.
TP29
A portable tank having a minimum test pressure of 1.5 bar may be used if it is shown that a test pressure of 1.5 bar or less is acceptable according to the test pressure definition in 6.7.2.1.