7 [ Back pressure valves as parts of machines; Ball valves being parts of machines; Hydraulic engines and motors; ] Hydraulic pumps; [ Hydraulic valve actuators; Lubricating pumps; Machine elements not for land vehicles, namely, pneumatic ball transfer units; Machine parts, namely, cylinders; Pneumatic air preparation equipment, namely, airline filters, lubricators, and regulators, all being parts of machines; Pumps for machines; Valves being parts of machines operated pneumatically and by air; Valves being parts of agricultural machines; Valves as machine components; ] Machine parts, namely, joints and joint parts for connecting sliding strips, plates and guides