Definition(s)
NU
Non-upset tubing connection.
Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards
NU
API Spec 5B non-upset tubing connection.
Source: API SPEC 5CT, Specification for Casing and Tubing, Upstream Segment, Ninth Edition, July 2011 (Errata September 2012). Global Standards