Trim No. and Leakage Rate in Globe / Gate valves 1

[670206]

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?
Thanks.

 

[V150]

TRIM NO ACCORDING TO API LIKE 1,5,8 ETC ARE RELATED TO DIFFERENCE IN HARDNESS / TO AVOID GALLING + SERVICE TEMPERATURE. NOT SURE IF RELATED TO LEAKAGE

 

[RXH]

There is no relationship between the trim number and the leakage rate. The trim number simply defines the materials of the two mating surfaces.

Leakage rate is determined by: type of seating i.e, soft-seated or metal-seated; type of valve i.e. gate, check, high performance butterfly, etc; surface finish; and other factors.

 

[PVRV]

Take a look at :

API 6A/598

for leakage rates.

 

[valvetech]

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.