Used in the construction of refinery piping where "sour" (high H2Scap H sub 2 cap S ) crude is processed.
To address these vulnerabilities, the National Association of Corrosion Engineers (NACE)—now part of AMPP (The Association for Materials Protection and Performance)—developed (now designated as NACE SP0472 ). This standard establishes strict guidelines for controlling weld hardness to prevent cracking in specific refinery environments.
Testing is typically performed using portable Brinell or Rockwell testers on actual production welds.
Elevating the temperature of the steel before welding slows down the cooling rate, preventing the formation of brittle martensite.
Methods include portable Brinell hardness testers or ultrasonic contact impedance (UCI) systems for field verification. Relationship with NACE MR0103 and MR0175
Are you an ASME or API member? Your library might have a reciprocal agreement with AMPP. Check your member portal for "Standards Access."
NACE RP0472 is a standard recommended practice titled "Methods and Controls to Prevent In-Service Environmental Cracking of Carbon Steel Weldments in Corrosive Petroleum Refining Environments" . First approved in 1972, it has been revised several times, with the most recent editions being RP0472-95, RP0472-2000, and RP0472-2005. It was later re-designated as (Standard Practice) around 2010, with a further revision in 2015.
If you need a legitimate copy for your work or company QA/QC manual, here are your options:
Once you have your legitimate PDF, here is a 5-step field checklist derived directly from the standard:
Essential Guide to NACE RP0472 (SP0472): Methods and Controls to Prevent In-Service Cracking of Carbon Steel Welds in Corrosive Environments
Stress Corrosion Cracking (SCC)
By strictly adhering to the guidelines set forth in NACE SP0472, refining operations can drastically reduce the risk of catastrophic environmental cracking, ensuring long-term asset integrity and personnel safety.
It relieves residual tensile stresses induced by the welding process. Weld Procedure Qualification (WPQR) and Testing