Charpy Impact test temperature 2

[AshaPatel]

I want to know what will be the Charpy Impact test temperature for API 5L X65M PSL2 material. This material is for subsea pipeline application. Design condition is Max. 80 degree centigrade and Min. is -29 degree centigrade. Pl. guide me if anybody have some inputs for the CVN test temperature.

 

[metengr]

If you cannot CVN impact test the material, I would suggest the following;

1. Review ASME B31.3
2. API 5L X65 material is listed and follows Curve A for minimum service temperature with impact exemption requirements.

 

[AshaPatel]

Thank you very much metengr. As per ASME B31.3 Curve B, Impact test to be exempted for -20 degree centi grade design temperature with the consideration of Plates shall be manufactured by thermo-mechanical controlled rolled process or supplied in the quenched and tempered condition and weld seam shall be fully normalized after the seam has been cooled to a temperature below 593°C (1100°F). Let me confirm my understanding is correct? Also guide me for DWT (Drop Weight Tear Test) test. what will be the test temp. for DWT test (-29 degree is min. design temp) or it is also exempted if impact test is exempted.

 

[weldstan]

What Code does this pipe come under; B31.3, B31.4, B31.8, other??

 

[AshaPatel]

the pipe code is API 5L, material grade is X65M PSL-2

 

[weldstan]

What Design Construction Code? These are the Codes which determine if impact testing is required at the minimum design temperature as per metengr.

 

[AshaPatel]

Design code is DNV-OS-F101 & Pipe Material specification and manufacturing code is API 5L, Material grade is X65M PSL2.

 

[SJones]

If you are using DNV-OS-F101, why can't you get the Charpy test temperature from Table 7-5 on page 114, or if supplementary F requirements are being applied, Table 7-23 on page 135? You will note that the test temperature is a function of the pipe wall thickness and pipeline minimum design temperature. Thus, you might like to question the derivation of -29 deg C in your case, since it smacks of someone simply looking at the lowest temperature without impact testing in ASME, as opposed to an engineering based derivation of minimum design temperature.

For DWT, DNV requires production of a transition curve, so there will be a range of test temperatures that will straddle the minimum design temperature.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

All answers are personal opinions only and are in no way connected with any employer.

 

[weldstan]

Thank you Steve.

 

[AshaPatel]

Thank you SJones for guiding me on perfect way to get the impact test temp. for low temp. service requirement.