NACE SP0170 is a standard practice document titled: The standard provides structured mitigation methods to protect these materials from PTA SCC, which can occur during the temporary cessation of operations in a refinery. A shutdown, according to the standard, includes the actual downtime period and the contiguous periods required to shut down and start up the equipment.
NACE SP0170 PDF: Protecting Refinery Equipment from Polythionic Acid Stress Corrosion Cracking nace sp0170 pdf