HYDRIL

WELL-DRILLING MACHINERY AND TOOLS-NAMELY, [ HYDRAULIC-FEED ROTARY TABLES, BEING WELL-DRILLING TOOLS EACH OF WHICH COMPRISES A ROTATABLE TABLE WITH APERTURE IN CENTER FOR CONTAINING THE END OF A SECTION OF PIPE AND MEANS FOR GRIPPING THE PIPE FOR ROTATING THE TABLE AND FOR ELEVATING OR DEPRESSING SAME BY A HYDRAULIC ELEVATOR; DRAW WORKS, ] TOOL JOINTS, [ UNDERREAMERS; CORE WORKING BARRELS; ] SAFETY JOINTS, [ BEING WELL-DRILLING TOOLS ] EACH OF WHICH COMPRISES A SECTION INSERTABLE IN A STRING OF PIPE SECTIONS CAPABLE OF BEING DISCONNECTED AT WILL TO PERMIT RAISING OF THAT PORTION OF THE PIPE WHICH IS ABOVE IT; [ CORE BITS, ] FISHING TOOLS; GAS-PRESSURE-CONTROL VALVES, BEING WELL-DRILLING TOOLS EACH OF WHICH COMPRISES A SECTION PROVIDED WITH A VALVE, USUALLY OF THE BALL AND SOCKET TYPE, FOR THE PURPOSE OF CONTROLLING THE PASSAGE OF GAS [ ; MUD PUMPS, STEAM ENGINES, HYDRAULIC TURBINES, STEAM TURBINES, OIL PUMPS AND PARTS THEREOF, WATER PUMPS AND PARTS THEREOF, STEAM CONDENSERS, INTERNAL-COMBUSTION ENGINES AND PARTS THEREOF ]