Pressure reduction plant for the distribution of fuel gas to a distribution network, said plant including three or more valve assemblies (10; 10a, 10b, 10c) arranged in parallel with each other and each valve assembly (10; 10a, 10b, 10c) including a pressure reducer (20; 20a, 20b, 20c), a pilot valve (30; 30a, 30b, 30c) and a pressure reducer device pneumatically connected to the respective pressure reducer (20; 20a, 20b, 20c) and to the respective pilot valve (30; 30a, 30b, 30c), in which: - each of said pressure reducers (20; 20a, 20b, 20c) is interposed between a supply line (4; 4a, 4b, 4c) and a delivery line to reduce the pressure of said fuel gas from the supply pressure (pa) present in said supply lines (4; 4a, 4b, 4c) to the delivery pressure (pm) present in said delivery line when said pressure reducer (20; 20a, 20b, 20c) is opened by a control pressure (pc); - each of said pilot valves (30; 30a, 30b, 30c) is configured to be closed by said delivery pressure (pm) and to transmit said control pressure (pc) to the respective pressure reducer (20; 20a, 20b, 20c) when said delivery pressure (pm) reaches the calibration value (pt, pt') of said pilot valves (30; 30a, 30b, 30c), there also being present: - derivation conduits each configured to transmit said delivery pressure (pm) from said delivery line to a respective pressure reducer (20; 20a, 20b, 20c), to a respective pilot valve (30; 30a, 30b, 30c) and to a respective pressure reducer device; - command lines each configured to transmit said control pressure (pc) from a respective pilot valve (30; 30a, 30b, 30c) to a respective pressure reducer (20; 20a, 20b, 20c), characterised in that each of said valve assemblies (10; 10a, 10b, 10c) further comprises a respective pressure reducer device, wherein any one of said pilot valves of any one of said valve assemblies (10; 10a, 10b, 10c) can be configured with a calibration value (pt') greater than the calibration value (pt) of all the remaining pilot valves (30b, 30c) belonging to the remaining valve assemblies (10; 10a, 10b, 10c) in such a way that said pilot valve controls all the pressure reducers (20; 20a, 20b, 20c) with the same control pressure, all said command lines are connected to each other via a single control line and each of said command lines communicates with said control line via a shut-off valve, wherein maneuvering the shut-off valves it is possible to isolate each valve assembly (10; 10a, 10b, 10c) from the other valve assemblies (10; 10a, 10b, 10c). - each of said pressure reducers (20; 20a, 20b, 20c) is interposed between a supply line (4; 4a, 4b, 4c) and a delivery line to reduce the pressure of said fuel gas from the supply pressure (pa) present in said supply lines (4; 4a, 4b, 4c) to the delivery pressure (pm) present in said delivery line when said pressure reducer (20; 20a, 20b, 20c) is opened by a control pressure (pc); - each of said pilot valves (30; 30a, 30b, 30c) is configured to be closed by said delivery pressure (pm) and to transmit said control pressure (pc) to the respective pressure reducer (20; 20a, 20b, 20c) when said delivery pressure (pm) reaches the calibration value (pt, pt') of said pilot valves (30; 30a, 30b, 30c), - derivation conduits each configured to transmit said delivery pressure (pm) from said delivery line to a respective pressure reducer (20; 20a, 20b, 20c), to a respective pilot valve (30; 30a, 30b, 30c) and to a respective pressure reducer device; - command lines each configured to transmit said control pressure (pc) from a respective pilot valve (30; 30a, 30b, 30c) to a respective pressure reducer (20; 20a, 20b, 20c),