The link
advertising for sale of the standards also gives a summary of the content.
I am not familiar with the detailed text of the documents, but for any valve leakage test worldwide you can ask yourself the question: when is it necessary that any specific valve conforms to(do not give more leakage than allowed) when tested after a certain leakage test?
Obviously when the valve is new, ideally all the time. If you have the safety of the installation (and operators) in mind you usually set down a maintenance and check scedule to ensure that the valves do not give (unreasonable) leakages above the selected test level, or alternatively have detection methodes giving alarm or maintenenance or service indication if leakage reaches a certain limit.
One side is the test methode description, the other side is the QA procedures for the plant describing how to locally apply the test as part of the total safety concept for the plant and process.
Use the following thought experiment: the neibour competing plant goes broke and want to sell you very cheap a lot of valves just put into service, but used, and qualified to the leakage test from two weeks to one year ago.
If you need the valves, how would you qualify the valves? And to what test criteria? What does your companys QA say?
And now the key question: how are you sure your own installed valves is better on leakage than the ones you considered buying and wanted to test before installation?