What is a proper procedure or better say method statement for pickling and passivating in stainless steel and duplex stainless steel pipes?

a380 standard

I thinks for pickling and passivation on S.S and Duplex steels requirements to be followed is standard A380.

Thanks so much for the help Guru!

 A380 standard requirements to be followed for pickling and passivation on S.S and Duplex steels