The 2016 edition was officially re-designated as (formerly RP0391) and is maintained by Task Group TG 372. The change from "RP" (Recommended Practice) to "SP" (Standard Practice) reflects NACE International's broader standardization efforts. According to the official NACE Store , the current active standard is NACE SP0391-2016 , and all previous editions (including RP0391-2001 and RP0391-91) are now listed as historical versions.
Key topics typically covered in RP 0391: nace rp 0391 pdf
Guidance on fluid velocity limits, turbulence mitigation, and geometry. The 2016 edition was officially re-designated as (formerly