Pressure reducing plant with two or more lines operating in parallel

A pressure reduction plant for the distribution of fuel gas to a distribution network, said plant including three or more valve assemblies arranged in parallel with each other and each valve assembly including a pressure reducer, a pilot valve and a pressure reducer device pneumatically connected to the respective pressure reducer and to the respective pilot valve, in which:

• each of said pressure reducers is interposed between a supply line and a delivery line to reduce a pressure of said fuel gas from a supply pressure present in said supply lines to a delivery pressure present in said delivery line when said pressure reducer is opened by a control pressure;
• each of said pilot valves is configured to be closed by said delivery pressure and to transmit said control pressure to the respective pressure reducer when said delivery pressure reaches a calibration value of said pilot valves,
• there also being present:
• derivation conduits each configured to transmit said delivery pressure from said delivery line to a respective pressure reducer, to a respective pilot valve and to a respective pressure reducer device;
• command lines each configured to transmit said control pressure from a respective pilot valve to a respective pressure reducer,
• wherein said pressure reduction plant includes:
• three or more valve assemblies;
• a shut-off valve for each command line;
• a single control line;
• and
• each of said valve assemblies includes:
• only one pressure reducer,
• only one respective pilot valve and
• only one respective pressure reducer device, all said command lines are connected to each other via said single control line, the single control line being isolated from the supply line of each of the three or more valve assemblies so that during operation of the pressure reduction plant, the fuel gas cannot pass from the supply line associated with one of the three or more valve assemblies, through the single control line and into one of the command lines;
• and
• each of said command lines communicates with said control line via said respective shut-off valve, wherein by maneuvering the shut-off valves it is possible to isolate each valve assembly from the other valve assembly,
• wherein any one of said pilot valves of any one of said valve assemblies can be configured with the calibration value greater than the calibration value of all the remaining pilot valves belonging to the remaining valve assemblies in such a way that said pilot valve with the greater calibration value controls all the pressure reducers with the same control pressure.