Control devices
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
In drilling operations in fields where high pressures, lost circulation, or other conditions exist which could result in blowouts, lessee shall install an approved gate valve or other controlling device which is in proper working condition for use until the well is completed. At all times preventative measures must be taken in all well operations to maintain proper control of subsurface strata.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.