Angle between the axis of a spiral-wound element (e.g. armour wires) and a line parallel to the longitudinal axis of the umbilical.
Source: API SPEC 17E, Specification for Subsea Umbilicals, Upstream Segment, Fourth Edition, October 2010. Global Standards
Angle between the axis of a spiral wound element (for example, armour wires) and a line parallel to the flexible pipe longitudinal axis.
Source: API SPEC 17J, Specification for Unbonded Flexible Pipe, Third Edition, July 2008. Global Standards