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. T20 Minimum test pressure (bar): 10 Minimum shell thickness (in mm-reference steel) (see 6.7.2.4): 8 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 L4BH: L = Type of tank: Tank for substances in the liquid state (liquids or solids handed over for carriage in the molten state). ------------------------- 4 = Calculation pressure: Minimum calculation pressure: 4 bar (see 6.8.2.1.14) ------------------------- B = Openings (see 6.8.2.2.2): Tank with bottom-filling or bottom-discharge openings with 3 closures. ------------------------- H = Safety valves/devices: Hermetically closed tank (see 1.2.1).