What is NACE bolting?
What is NACE bolting?
NACE bolting is a term used for bolts that are in compliance with NACE MR0175. NACE MR0175 is an international standard that provides the requirements for metallic materials exposed to H2S in oil and gas production environments. NACE MR0175 is identical to ISO 15156. ANSI / NACE MR0175 / ISO 15156 lists the requirements for carbon steels, low alloys and corrosion resistant alloy exposed to H2S in oil and gas exploration and production environments.
Bolt compliance to NACE MR0175 sometimes can be confusing confusion, for example flange bolts are not in direct contact with the transport fluids, however a leak may expose them to H2S. NACE MR0175 / ISO 15156 -2 section A.2.2.4 addresses this matter by stating “Bolting that can be exposed directly to a sour environment, or that is buried, insulated, equipped with flange protectors or otherwise denied direct atmospheric exposure or direct open seawater exposure, shall conform to the general requirements of A.2.1.”