ALEXANDRIA, Va., March 12 -- United States Patent no. 12,247,669, issued on March 11, was assigned to National Oilwell Varco LP (Houston).
"Valve assembly for well systems" was invented by James W. Weir (Cypress, Texas) and Jonathan Lewis Buelow (Houston).
According to the abstract* released by the U.S. Patent & Trademark Office: "A valve for a well system including a valve housing including a first housing port, a second housing port, and a bore, a piston received in the bore and including a first end, a second end, and an annular flange including a first annular surface and a second annular surface both of which are in fluid communication with the second housing port, a piston seal disposed in the outer surface of the piston and in seal...