NACE Standards MR0103 vs MR0175
NACE MR0175 and NACE MR0103 are both standards that provide requirements for metallic materials used in the oil and gas industry. A primary difference between the two is the intended environment for use, with MR0175 for upstream extraction operations and MR0103 for downstream refinery environments
NACE MR0103 was developed as a downstream refinery specific standard for sour service metallic materials in 2003 (the 03 in MR0103).
NACE MR0175 which applies to only oil and gas production, or upstream activities was introduced in 1975 (the 75 in MR0175).
NACE MR0103 applies to downstream refining environments which are generally a high pH sour service environment with low chloride ion concentrations. High pH is primarily due to lower concentrations of CO2 as compared to upstream operations.
NACE MR0175 applies to upstream drilling and production environments which are generally a low pH sour service environment with high chloride ion concentrations. Low pH is primarily due to the increased concentration of CO2 as compared to downstream operations.
Previous to the introduction of MR0103 the industry widely used MR0175 to specify requirements for downstream refinery applications even though it had been recognized that refining environments were outside its scope. Confusion still exists in the industry as a result of the historical use of MR0175 and end users, industry organizations, and manufacturers in many cases still need to update their engineering specifications to properly apply the MR0103 standard for refinery environments.
