Definition(s)
Lower Kelly Cock
Also called drill-stem safety valve, see drill-stem safety valve.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards
Oil & Gas Drilling Glossary - IADCLexicon.org
Also called drill-stem safety valve, see drill-stem safety valve.
Source: IADC UBO / MPD Glossary, December 2011. Global Standards