A flexible hose assembly used to convey high-pressure drilling liquids between the top of the mud standpipe and the rotary swivel.
Source: API SPEC 7K, Drilling and Well Servicing Equipment Upstream Segment, Fifth Edition, June 2010 (August 2010). Global Standards
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards