41 Training in the use, operation and repair of machines, namely, pumps, rotary pumps, piston pumps, single-phase and multi-phase pumps, single-stage and multi-stage pumps, axial pumps, radial pumps, pumps for liquids, gases, solid materials and mixtures thereof, pumps for petroleum, gases, pulp, water and granular materials, mixers, agitators, conveyors; and educational services, namely, conducting training classes in the repair and maintenance of installations consisting of machines, namely, of pumps, rotary pumps, piston pumps, installations consisting of single-phase and multi-phase pumps, single-stage and multi-stage pumps, axial pumps, radial pumps, installations consisting of pumps for liquids, gases, solid materials and mixtures thereof, installations consisting of pumps for petroleum, gases, pulp, water and granular materials, and installations consisting of mixers, agitators, conveyors