scope:

This recommended practice (RP) discusses environmentally assisted cracking of carbon steel equipment in amine treating units. Amine stress corrosion cracking and sulfide stress cracking of stainless steels in amine units is beyond the scope of this document, although there have been isolated reports of such problems. This RP provides guidelines for carbon steel construction materials including their fabrication, inspection, and repair to help assure safe and reliable operation. The carbon steels referred to in this document are defined by the ASTM designation system, or are equivalent materials contained in other recognized codes or standards. Welded construction is considered the primary method of fabricating and joining amine unit equipment. See terms 3.6 and 3.7 for the definitions of weld and weldment.

This document is based on current engineering practices and insights from industry experience. Older amine units may not conform exactly to the information contained in this RP, but this does not imply that such units are operating in an unsafe or unreliable manner. No two amine units are alike, and the specific strategies to avoid cracking in a unit will be customized to that unit. Each user company is responsible for safe and reliable unit operation.

Rotating equipment is specifically excluded from the API 945 scope. However, API 610 on centrifugal pumps does have a table that recommends PWHT of all welds in amine services.