I would like to know CVN number for X70 grade Pipeline (PSL2) by using G.9 Battelle two-curve method - Approach -3(API 5L).

Dear all,

I would like to know CVN number for X70 grade Pipeline (PSL2) by using G.9 Battelle two-curve method - Approach -3(API 5L).

The Issue is related to arresting the propagation of a crack due to ductile fracture in the event that a crack/fracture/rupture occurs. For example, such crack may be initiated at an inclusion in the pipe metal, or at some point of mechanical damage or some other cause.

The issue has nothing to do with controlled blowdown of the pipeline, nor the metal temperature during controlled blowdown.
Approach 4 as set out in G10 of API 5L  states, and I quote
" is suited for fluids that exhibit single-phase behaviour during depressuring"  
We all agree that liquid will form during depressuring, and hence Approach 4 is NOT applicable ( and not acceptable to Engineering).
Only Approach 3 is suitable as it is clearly stated in API 5L and I quote, 
"it is suited for fluids that exhibit single-phase decompression behaviour and for rich gases that decompress into the two-phase boundary"
No other method in API 5L is suited to rich gases which form liquid during decompression.

Please any one can help me ...

Thanks and Regards,

Maheswara Reddy Kambam