are API issues codes or standards ? 3

[engahmedbahgat]

hi all, I'm asking about API issues , especially in piping work as API 5D, API 6D, API 598 and so on. are these issues can be considered codes or standards or some issues are codes and other ones are standards ??
thank you in advance

 

[DekDee]

Rather interesting - this is how B31 started out

American National Standard Code for Pressure Piping.