Number of pressure cycles in valves for fatigue

[raton]

Hi All.
I have a question regarding the number or cycles for a valve during a pressure fatigue test

I have in front of me a technical specification where the number of pressurization cycles depending at pressure test (based on the MAWP) are:

68.000 pressure cycles @ 1,5 MAWP
175 pressure cycles @ 1,2 MAWP
35 pressure cycles @ MAWP

Do you know if there is any standard or rule with the above values or do you think that those values are specific for a manufacturer?

Thank you very much for your help

Jaime