37 Installation, maintenance, reconditioning, and repair of transformers, transformer components in the nature of padmount transformers, substation transformers, pole mount transformers, dry type transformers, switchgear, pad mount electrical switches, switchboards, and electrical transfer switches, and other power-generating electrical equipment, such as bushings, surge arresters, pressure release devices, temperature gauges, pressure gauges, liquid level gauges, oil drain valves, line hardware, spade connectors, and gaskets