A valve that employs a rotating ball to open or close the flow passage.
Source: API RP 64, Recommended Practice for Diverter Systems Equipment and Operations, Second Edition, November 2001 (March 1, 2007). Global Standards
ball-shaped valve with conduit port and 90 degree rotation. Normally full port with minor pressure loss.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards