Unless otherwise indicated in these provisions, cylinders and pressure drums conforming to the applicable requirements of Chapter 6.2 are authorized.

(1) The general packing requirements of 4.1.6.1 shall be met.

(2) The maximum test period for periodic inspection shall be 5 years.

(3) Cylinders and pressure drums shall be so filled that at 50°C the non-gaseous phase does not exceed 95% of their water capacity and they are not completely filled at 60°C. When filled, the internal pressure at 65°C shall not exceed the test pressure of the cylinders and pressure drums. The vapour pressures and volumetric expansion of all substances in the cylinders and pressure drums shall be taken into account. For liquids charged with a compressed gas both components ­ the liquid and the compressed gas ­ have to be taken into consideration in the calculation of the internal pressure in the pressure receptacle. When experimental data is not available, the following steps shall be carried out:
(a) calculation of the vapour pressure of the liquid and of the partial pressure of the compressed gas at 15° (filling temperature);

(b) calculation of the volumetric expansion of the liquid phase resulting from the heating from 15°C to 65°C and calculation of the remaining volume for the gaseous phase;

(c) calculation of the partial pressure of the compressed gas at 65°C considering the volumetric expansion of the liquid phase;
Note: The compressibility factor of the compressed gas at 15°C and 65°C shall be considered.

(d) calculation of the vapour pressure of the liquid at 65°C;

(e) the total pressure is the sum of the vapour pressure of the liquid and the partial pressure of the compressed gas at 65°C;

(f) consideration of the solubility of the compressed gas at 65°C in the liquid phase.

The test pressure of the cylinders or pressure drums shall not be less than the calculated total pressure minus 100 kPa (1bar).
If the solubility of the compressed gas in the liquid phase is not known for the calculation, the test pressure can be calculated without taking the gas solubility (subparagraph (f)) into account.

(4) The minimum test pressure shall be in accordance with P200 for the propellant but shall not be less than 20 bar.

Additional requirement:
Cylinders and pressure drums shall not be offered for transport when connected with spray application equipment such as a hose and wand assembly.


Special packing provision PP97:
For fire-extinguishing agents assigned to UN 3500 the maximum test period for periodic inspection shall be 10 years. They may be transported in tubes of a maximum water capacity of 450 L conforming to the applicable requirements of chapter 6.2.