FerroPipe meets the requirements of sour gas service per NACE MR0175. National Association for Corrosion engineers– NACE is the material (CS or SS) used in specific application/service where high corrosion occur due to sulfur/hydrogen embrittlment. e.g. generally NACE material is used in salty environment i.e. offshore equipments .
NACE pipe can be supplied in two specifications that provide guidance on reducing the risk of in-service cracking, one of these also being an ISO standard. The major difference between these two primary specifications is the definition the environmental and service conditions for sour service.
The first standard, ANSI/NACE MR0175/ISO 15156, Petroleum and natural gas industries – Materials for use in H2S-containing environments in oil and gas production, is intended for offshore
Applications and NACE MR0103, Materials Resistant to sulphide stress cracking in corrosive petroleum refining environments, for onshore process plant. The latter specification refers to a recommended practice document for controlling welding activities to ensure a low and acceptable weldment hardness; NACE SP0472, Methods and controls to prevent in-service environmental cracking of carbon steel weldments in corrosive petroleum refining environments.
Both MR0175 and MR0103 have virtually identical requirements for specifying parent metal properties of carbon steels for sour service; the principal additional requirement being a maximum hardness. All steels that have been cold-worked must be stress relief heat treated to ensure the hardness is less than 22HRC (Rockwell hardness, equivalent to 248Hv or 235HB). Carbon steels other than P1 can be used provided that their hardness is also less than 22HRC.