11 Burners; gas safety shut-off valves; air valves for steam heating installations; gas level controlling valves in tanks; regulating accessories for water or gas apparatus and pipes, namely, gas filters, ball valves, safety shut-off valves, pressure switches, pressure regulators, valve proving apparatus, namely, control unit, pressure sensor, pressure switch, pump, automatic burner controls; safety accessories for gas apparatus and pipes, namely, gas filters, ball valves, safety shut-off valves, pressure switches, pressure regulators, valve proving apparatus, namely, control unit, pressure sensor, pressure switch, pump, automatic burner controls; regulating and safety accessories for gas pipes, namely, gas filters, ball valves, safety shut-off valves, pressure switches, pressure regulators, valve proving apparatus, namely, control unit, pressure sensor, pressure switch, pump, automatic burner controls; regulating and safety accessories for gas apparatus, namely, gas filters, ball valves, safety shut-off valves, pressure switches, pressure regulators, valve proving apparatus, namely, control unit, pressure sensor, pressure switch, pump, automatic burner controls; thermostatic valves as parts of heating installations