Yes, if the PS of the compressed air is greater than 0,5 bar. The PS of com- pressed air and internal volume of the tank determine the category according to the table 2 of Annex II.
Reason:
Slurry tankers are not excluded from the scope of the PED due to Article 1 paragraph 2 (s). They are not tanks intended for carriage of dangerous goods.
Note:
“Slurry tanker” is used in farms to fertilize the fields with liquid manure. It is a tank on wheels usually pulled by a tractor in the fields and from one field to another. Compressed air facilitates the emptying of the tank.
See also PED Guideline A-02.