The portable tank instructions T1 to T22 apply to liquid and solid substances of Class 1 and Classes 3 to 9. The general provisions of Section 4.2.1 and the requirements of Section 6.7.2 shall be met. The instructions for portable tanks with FRP shells apply to substances of classes 1, 3, 5.1, 6.1, 6.2, 8 and 9. Additionally, the requirements of Chapter 6.9 apply. T22 Minimum test pressure (bar): 10 Minimum shell thickness (in mm-reference steel for shells made of metallic materials) (see 6.7.2.4): 10 mm Pressure-relief requirements (see 6.7.2.8): See 6.7.2.8.3 Bottom opening requirements (see 6.7.2.6): Not allowed *) *) When "Not allowed" is indicated, bottom openings are not permitted when the substance to be carried is a liquid (see 6.7.2.6.1). When the substance to be carried is a solid at all temperatures encountered under normal conditions of carriage, bottom openings conforming to the requirements of 6.7.2.6.2 are authorized.

Code L21DH(+): L = Type of tank: Tank for substances in the liquid state (liquids or solids handed over for carriage in the molten state). ------------------------- 21 = Calculation pressure: Minimum calculation pressure: 21 bar (see 6.8.2.1.14) ------------------------- D = Openings (see 6.8.2.2.2): Tank with top-filling and discharge openings with no openings below the surface of the liquid. ------------------------- H = Safety valves/devices: Hermetically closed tank (see 1.2.1). ------------------------- (+) = The indication of a "(+)" after the tank code means that the substance is subject to special provisions. In that case the alternate use of the tanks for other substances and groups of substances is permitted only where this is specified in the certificate of type approval. Higher value tanks according to the provisions at the end of the table in 4.3.4.1.2 may be used with due regard to the special provisions indicated in Column (13) of Table A in Chapter 3.2.

(a) A vehicle, other than EX/III or FL vehicle or than a MEMU, intended for the carriage of dangerous goods in fixed tanks or demountable tanks with a capacity exceeding 1 m³ or in tank-containers, portable tanks or MEGCs with an individual capacity exceeding 3 m³; or (b) A battery-vehicle with a total capacity exceeding 1 m³ other than a FL vehicle.