As of 2025, the official NACE SP0170 PDF 2021 costs approximately $150–$250 for members (less if you join AMPP). For a piece of equipment that costs millions, this is a trivial investment.
NACE SP0170 PDF 2021 has significant implications for industries that use equipment and components in petroleum refining and petrochemical environments. Some key implications include:
PTA is not typically present during normal refinery operations. Instead, it forms during shutdowns or turnarounds when the following sequence occurs: nace sp0170 pdf 2021
: To prevent the formation of polythionic acids ( H2SxO6cap H sub 2 cap S sub x cap O sub 6
The standard provides specific mitigation methods to protect equipment—such as heaters, tubes, and reactors—during the downtime, shutdown, and startup phases of refinery operations. PTA SCC occurs when sulfide corrosion products react with oxygen and water to form polythionic acids, which can rapidly cause cracking in sensitized austenitic alloys. As of 2025, the official NACE SP0170 PDF
The NACE SP0170 standard, specifically the 2021 version, provides guidelines and best practices for the application of impressed current cathodic protection (ICCP) systems. These systems are designed to protect steel water storage tanks from corrosion. The standard covers various aspects, including:
NACE SP0170 is an industry standard practice officially titled Some key implications include: PTA is not typically
This method focuses on environmental control. The standard defines as using a flow of an inert gas, specifically dry nitrogen , to remove oxygen from the equipment. By eliminating oxygen, the formation of polythionic acid is chemically blocked. However, the equipment must be maintained under a positive pressure of dry nitrogen, and the gas must indeed remain dry, as moisture is the other necessary component for acid formation.