Nace Rp0472 - Pdf
Essential for pressure vessels, heat exchangers, and piping exposed to wet cap H sub 2 cap S (sour service) in refining units. Key Updates:
NACE RP0472 (now updated to NACE SP0472 ) is the essential standard for preventing environmental cracking in carbon steel weldments used in petroleum refining. It specifically targets "P-1" steels (those with a tensile strength ≤ 70,000 psi). The standard focuses on two primary cracking mechanisms: Hydrogen Stress Cracking (HSC): Controlled by limiting the of the weld deposit and the heat-affected zone (HAZ). Alkaline Stress Corrosion Cracking (ASCC): Prevented primarily through Post-Weld Heat Treatment (PWHT) to reduce residual tensile stresses. Key Technical Requirements Hardness Limit: The standard specifies a maximum weld deposit hardness of (Brinell). HAZ Control: nace rp0472 pdf
Provides guidelines to prevent environmental cracking (e.g., sulfide stress cracking, hydrogen-induced cracking, stress corrosion cracking) in carbon steel weldments used in wet H₂S (sour) service and other corrosive refinery environments. Essential for pressure vessels, heat exchangers, and piping
The standard provides essential guidelines for producing weldments in that can resist environmental cracking in corrosive refinery settings. It primarily addresses two major cracking threats: The standard focuses on two primary cracking mechanisms:
