7 parts of machines for oil and gas well drilling, fracturing, stimulation, production and flow processing systems, namely, christmas trees, wellheads, tubing heads, tubing hangers and casing hangers; pumps being machines for oil and gas well drilling, fracturing, stimulation, production and flow processing; truck, trailer and skid-mounted pumps for oil and gas well drilling, fracturing, stimulation, production and flow processing; manifolds being machines for oil and gas well drilling, fracturing, stimulation, production and flow processing; truck, trailer and skid-mounted manifolds for oil and gas well drilling, fracturing, stimulation, production and flow processing; parts of machines for oil and gas well drilling, fracturing, stimulation, production and flow processing systems, namely, flow control valves, gate valves, plug valves, check valves, and butterfly valves; power operated pneumatic, electric and hydraulic valve actuators; parts of machines for oil and gas well drilling, fracturing, stimulation, production and flow processing systems, namely, pressure relief valves, chokes, choke manifolds, and choke and kill manifolds; hydraulic and electrohydraulic controls for operating oil and gas well drilling, fracturing, stimulation, production and flow processing system components; hydraulic power units; machines for separating oil, gas, water and/or solids from well fluids; machines for separating sand and particulates from well fluids; parts of machines for oil and gas well drilling, fracturing, stimulation, production and flow processing systems, namely, swivel joints, articulated frac arms, and articulated frac arm manifolds; automatic greasing systems for valves; seal assemblies being parts of machines; packoffs being parts of machines