Is there any relationship between trim no. specified in API 600 and leakage rate specified by DIN 3230-3 or any other standards in a globe or gate valve.
here is a simple look at the most common leakage classes and how valves are tested to establish that leakage rate.
ANSI CLASS         Class III         
Maximum Seat Leakage     0.1% of rated valve capacity      Test Conditions
Air or water @ 50 - 125 F.               45 - 60 psig or Maximum operating differential pressure whichever is less
ANSI                    Class IV              Maximum Seat Leakage    0.01% of rated valve capacity     Test Conditions   
Air or water @ 50 - 125 F.               45 - 60 psig or Maximum operating differential pressure whichever is less
ANSI                     Class VI                  Maximum Seat Leakage     1" Port Diameter        
0.15 ml per minute or 1 bubble per minute    
Test Conditions   
Air or Nitrogen @ 50 - 125 F          50 psig or Maximum operating differential pressure whichever is less
Simplified Chart for most popular leakage classes. For complete specifications refer to ANSI/FCI 70-2
This should at least give you a start on leakage classifications.

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