For CE mark, PED,  the Group selection is required.  You have to tell us group based on the fluid handled in the system for each equipment. For example
FFE- Shell side - steam and tube side process fluid i.e. Nitric acid 
Condenser - Shell - Nitric acid, Tube cooling water. 
Hold up receivers for distillate and concentrate- Nitric acid. 

Following is the group list.  Please confirm w.r.t. the same.

Group-I
--------
Explosive
Extremely flammable
Highly flammable
Flammable
Very toxic
Toxic
Oxidising

Group-II
----------
Others

In each case you should tell us the Fluid type i.e. Liquid or Gas.

Please confirm at the earliest   

             