API 6X application component

[bawest47232]

Should API 6X apply to a pressure controlling/containing component in the wellbore? For instance a position shaft used on a gate valve? The shaft is a solid piece and while it sees wellbore pressure, there is not a pressure differential through the shaft except at the seals on the bonnet.

API 6X does not allow for the use of compressive stress or buckling calculations. However these would be the correct stresses to apply for this situation

ASMR allows buckling calculations in viii div 2 under combined loading. Why would 6X not allow the same design calculations for the same situation?

API 6X is only for specific components such as bonnets, bodies and end connections. Should the the ram shafts be designed in accordance is 6X?

Disclaimer, I am not well versed in this situation so, I'm sorry if I'm wasting your time asking and if my terminology is wrong.

 

[NRP99]

Read note provided under-API 6X-4.1 Failure modes para 4.1-Application. The buckling failure mode is outside the scope of the API 6X but can be evaluated using the ASME BPVC since the API 6X requirements are similar to BPVC.

All envisaged failure modes are need to be addressed by design engineer/Analysis engineer irrespective of the code requirements.