Granted Patent
Utility
US 5,316,086 · App. 07/990,639
Combination well casing pressure relief and kill valve apparatus
Inventor:
Edward E. DeMoss
Patented Case
View Patent ↗
Granted: May 31, 1994
Filed: Dec 14, 1992
Inventor
Edward E. DeMoss
Assignee (at issue)
Halliburton
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.