See Choke and Kill Lines.
Source: API RP 16Q, Recommended Practice for Design, Selection, Operation and Maintenance of Marine Drilling Riser Systems, First Edition, November 1993 (Reaffirmed August 2001). Global Standards
The high-pressure piping between the pumps and BOP outlets or wellhead outlets.
Source: API RP 59, Recommended Practice for Well Control Operations, Second Edition, May 2006. Global Standards
A high-pressure line from the mud pumps to a connection below a BOP that allows fluid to be pumped into the well or annulus with the BOP closed during well control operations.
Source: API SPEC 16D, Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment, Upstream Segment, Second Edition, July 2004. Global Standards
High-pressure line between the mud pump and the blowout preventer to facilitate the pumping of fluid into the hole to overcome well pressure with the preventers closed.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards
External conduit arranged laterally along the riser pipe and used for circulation of fluids into and out of the wellbore to control well pressurelanding joint riser joint temporarily attached above the telescopic joint used to land the BOP stack on the wellhead when the telescopic joint is collapsed and pinned.
Source: ISO 13624-1:2009, Petroleum and natural gas industries – Drilling and production equipment – Part 1:Design and operation of marine drilling riser equipment. Global Standards