ALEXANDRIA, Va., June 4 -- United States Patent no. 12,320,439, issued on June 3, was assigned to SPM Oil & Gas Inc. (Forth Worth, Texas).
"Dart valve" was invented by Justin Poehls (Glen Rose, Texas) and David Figgs (Fort Worth, Texas).
According to the abstract* released by the U.S. Patent & Trademark Office: "A dart valve comprises a valve housing. The valve housing comprises a valve inlet, a valve outlet, a housing wall and an aperture extending through the housing wall between the valve inlet and valve outlet. The dart valve further comprises a valve cartridge. The valve cartridge comprises a cartridge housing configured to allow fluid to flow therethrough from a cartridge inlet to a cartridge outlet; and a valve plunger slidably mou...