WO2016128811A1

WO2016128811A1 - System for operating and controlling valves

Info

Publication number: WO2016128811A1
Application number: PCT/IB2015/059039
Authority: WO
Inventors: Ivano DANIELE; Andrea GAGGIOTTI
Original assignee: Navalimpianti Spa
Priority date: 2014-11-25
Filing date: 2015-11-23
Publication date: 2016-08-18

Abstract

System for operating and controlling valves (1) intended to control an electro-hydraulic system on board a vessel, each valve (1) comprising at least one actuating unit (11) for regulating the operation thereof. The system comprising at least two power units (21, 31), of which a first power unit (21) and a second power unit (31), which power units (21, 31) are connected to the actuating units (11) of each valve (1). The first power unit (21) and the actuating units (11) are connected through a series connection, namely there being provided a single transmission line (4) intended to connect in series the first power unit (21) to said actuating units (11), which transmission line (4) is intended to transmit at least the power signal. The second power unit (31) and the actuating units (11) being connected through a series connection, namely there being provided a single transmission line (4) intended to connect in series the second power unit (31) to said actuating units (11), which transmission line (4) is intended to transmit at least the power signal. The first power unit (21) and the second power unit (31) being placed at the ends of the transmission line (4), there being provided breaking members (111,112, 113, 114, 115, 116, 117, 118, 121, 131) for the transmission line (4) between each actuating unit (11) and the following one, as well as between the first power unit (21) and the actuating unit (11) directly connected thereto and between the second power unit (31) and the actuating unit (11) directly connected thereto, such that each actuating unit (11) provides an input breaking member and an output breaking member. Moreover each breaking member (111, 112, 113, 114,115, 116, 117, 118, 121, 131) is intended to open or close said transmission line (4) and the first power unit (21) being directly connected to the second power unit (31).

Description

System for operating and controlling valves.

The present invention relates to a system for operating and controlling valves intended to the control of an electro-hydraulic system on board a vessel, each valve comprising at least one actuating unit for regulating the operation thereof.

The system of the present invention comprises at least two power units, of which a first power unit and a second power unit, which power units are connected to the actuating units of each valve.

The one just described is one of the possible configurations of systems for operating and controlling valves of hydraulic systems, with a particular reference to systems installed on board vessels.

As all the apparatuses on board vessels, such systems have to meet particular safety requirements, in particular in case of failure they have to allow at least a part of the system to operate until the first available berth.

With a particular reference to systems for operating valves of the hydraulic system, the systems known in the prior art provide to use a control board that autonomously handles one or more valves and which can be automatic or controlled by an operator such to regulate the operation of the valves .

Preferably the control board acts on an electric control unit that transmits control signals to the valve, such to regulate the opening and closure thereo .

A possible configuration of systems known in the prior art provide a "star" connection, that is each valve is connected, through its control unit, to the main board through a dedicated cable.

However such configuration mainly provides to use a considerable amount of connection cables , which obviously has direct consequences on rises in costs.

Moreover due to the fact that regulations, which have to be met by vessels, provide the vessel to be divided into compartments, a main requirement is that a failure, for example a fire, has to limit the damages to the compartment where such failure takes place, without causing malfunctions in adjacent compartments.

Therefore by using the "star" configuration it is necessary to have a control board for each compartment, but such solution, in addition to cause costs to rise, is often impracticable since it is not always possible to install control boards in all the vessel compartments.

Moreover the installation of control boards in specific compartments, such as for example the compartments placed under the water line of the vessel, is difficult since such boards, still on the basis of the current regulations, have to show further safety characteristics, that make maintenance and inspection procedures thereof particularly difficult.

Finally because fires are the main reason of failures in the systems known in prior art, a known solution is to make the valves and the components of the system as ire-resistant.

However it is not possible to guarantee the proper operation of valves since at high temperatures the employed electronics has malfunctions that compromise the valve control .

The use of electronics not affected by rises in temperature would require too high costs.

Therefore there is the unsatisfied need in the prior art to provide a system for operating and controlling valves of an hydraulic system on board a vessel that solves the drawbacks and malfunctions just described, without requiring a high rise of costs and that is in compliance with current regulations in the marine field.

The present invention achieves the above objects by providing a system as described hereinbefore wherein the first power unit and the actuating units are connected through a series connection, namely there being provided a single transmission line intended to connect in series the first power unit to the actuating units, which transmission line is intended to transmit at least the power signal .

Similarly the second power unit and the actuating units are connected through a series connection, namely said second power unit being connected to one end of the single transmission line said first unit being connected at the other end of the same transmission line which is intended to connect in series said first power unit to the actuating units, which transmission line is intended to transmit at least the power signal. The first power unit and the second power unit are thus placed at the opposite ends of the transmission line .

There are further provided breaking members between each actuating unit and the following one, as well as between the first power unit and the actuating unit directly connected thereto and between the second power unit and the actuating unit directly connected thereto, such that each actuating unit provides an input breaking member and an output breaking member.

Each breaking member is intended to open or close the transmission line, preventing at least the power signal from being transmitted.

Finally the first power unit is directly connected to the second power unit.

Unlike systems known in the prior art, such configuration in series allows a ring system and not a star system to be obtained that requires a single connection between the power unit and each individual valve, through its actuating unit.

The presence of a second power unit obviously allows the power signal to be transmitted by both the ends of the transmission line, such to power all the actuating units in case of a break of the line.

As it will be disclosed below the system of the present invention is particularly efficient in detecting the failure and in maintaining the valve as operating in case of malfunctions or failures on the line or of the components.

According to a possible embodiment, the breaking members are provided into each individual actuating unit .

Each input breaking member is therefore composed of a primary input breaking member and a secondary input breaking member and each output breaking member is composed of a primary output breaking member and a secondary output breaking member.

Moreover each actuating unit has a diagnostic unit intended to detect the integrity of the transmission line, the diagnostic unit being connected to the transmission line through the secondary input and output breaking members .

The activation or deactivation of the secondary input and output breaking members allows the diagnostic unit to be connected or disconnected from the transmission line and it has advantages as regards failure detection and in restoring the system power, with advantages that will be described more clearly below.

In order to optimally meet the requirements of the current regulations, the first power unit and the second power unit are electrically connected, but they are placed in two different control units.

According to a preferred embodiment, the first power unit is contained in a first main unit which comprises processing means for executing a first logic program and the second power unit is contained in a second main unit, which comprises processing means for executing said first logic program.

The first main unit is connected to the second main unit both directly and through the connection in series of the actuating units.

Therefore it is clear how the second main unit is the so called "hot spare" of the first main unit, namely two units that communicate and that are identical instant by instant.

The ring network just described allows therefore the required safety standards to be maintained by limiting costs, components and installation time.

Obviously there is a physical limit for the number of valves that can be controlled by a pair of main units, we suppose that such number is about equal to fifty valves for each ring for a maximum of 7 rings corresponding to a maximum of 350 valves for a pair of main units.

Therefore a further advantage of the system of the present invention appears that is its modularity: it is possible to design two or more systems as described before, such to handle all the valves of the vessel, without requiring too much material or unsatisfactory installation and operating time.

According to a possible variant embodiment, each actuating unit comprises processing members for executing a second logic program.

The actuating units can be intelligent and carry out predetermined and specific actions depending on how they are programmed.

They can further provide information to the main units about the opration of the valve to which they are associated. According to such con iguration the actuating units are preferably connected in series to the main units not only as regards power, but also as regards data communication.

For this reason in order to facilitate the installation of the system of the present invention, as well as in order to optimize spaces within the vessel, the transmission line is intended to transmit the power signal and a signal containing information.

According to one embodiment, each actuating unit is connected to said transmission line through mechanical/electrical connection elements composed alternatively of cable entries IP68 and connection with internal terminal block with screw connection or with plug connector.

From what disclosed up to now it is clear how the system of the present invention, in addition to have the described adavantages , can be configured for implementing a method that allows, in case of failure on the transmission line or of one of the system components, the functionalities of the valves to be quickly restored.

For this reason the processing means of the main units and of the actuating units can be programmed such to execute specific steps directed at isolating the malfunctioning part, guaranteeing efficiency of the remaining part of the system.

According to a preferred embodiment, the execution of the first and/or second logic program provides the following steps: a) detecting possible signal transmission breaks on the transmission line,

b) opening the breaking members and breaking the power signal ,

c) the first power unit and the second power unit sending the power signal by to the directly connected actuating units, closing the input breaking member of the actuating unit directly connected to the first power unit and the input breaking member of the actuating unit directly connected to the second power unit,

d) the actuating units directly connected to the first and second power units sending a signal to the following actuating unit, intended to detect the integrity of the transmission line,

e) if breaking is detected isolating the following actuating unit,

f) if breaking is not detected propagating the power signal to the following actuating unit,

g) closing the output breaking member of the actuating unit directly connected to the first power unit and the output breaking member of the actuating unit directly connected to the second power unit.

Such execution steps are repeated for each actuating unit till detecting the one nearest to the failure on the line.

Such method will be more clear by the description of some embodiments annexed to the present patent application, but it is clear that the isolation of only the actuating unit having the failure or placed near the failure is achieved.

The ring configuration allows the actuating units preceding the failure to be properly powered by the first power unit and the actuating units following the failure to be properly powered by the second actuating unit .

Moreover diagnostic about the integrity of the line performed by an actuating unit towards the following actuating unit is preferably carried out by transmitting a low voltage signal.

Such aspect, together with the characteristic of making "intelligent" actuating units allows the system to be restored more quickly: after failure detection the transmission of the power signal is stopped, the system is started again and it quickly operates electronics of the actuating units carrying out the diagnosis and allows the failure to be isolated.

Therefore the line is restored safely, efficiently and it allows a minimum number of actuating units to be isolated, guaranteeing the proper operation of the remaining ones till the first available berth.

Considering the advantageous characteristics described, according to a possible embodiment of the disclosed method, step c) provides to close the secondary input breaking member of the actuating units directly connected to the first and second power units, as well as the first power unit and the second power unit sending the power signal to the directly connected actuating units.

According to such embodiment step d) provides the actuating units directly connected to the first and second power units to send a signal, through the diagnostic unit, to the following actuating unit, intended to detect the integrity of the transmission line.

Step e) provides to open the primary output breaking member and to close the primary input breaking member if breaking is detected, consequently isolating the following actuating unit.

Then step f) provides to close the primary output breaking members of the actuating units directly connected to the first and second power units if breaking is not detected, consequently propagating the power signal to the following actuating unit.

Advantageously the main units can have all the instruments known in the computer field.

In particular the first main unit and the second unit can comprise a display unit and an input/output interface .

Therefore firstly it will be possible to obtain a feedback about the operation of each individual valve and to intervene in order to regulate the operation thereof .

Obviously the system of the present invention is both automatically and manually operated, namely an operator can intervene in any moment and with different priority levels for handling the execution of the method disclosed above.

Moreover it is possible to provide inputs and outputs for connecting the main unit to a computer such to program it by means of an external unit.

On the basis of the described aspects, advantageously the transmission line can be composed of a single transmission line connecting all the components of the system.

As an alternative the transmission line can be composed of a first transmission line intended to connect in series the first power unit to the actuating units and of a second transmission line intended to connect in series the second power unit to the actuating units.

According to a preferred embodiment, each actuating unit is connected to the transmission line through mechanical/electrical connection elements composed of a first part of a plug connector cooperating with a corresponding second part of a plug connector .

The first part of the connector being fastened to the ends of the transmission line, while the second part is fastened to the actuating unit.

Such particular configuration allows each actuating unit to be quickly and independently connected and disconnected from the transmission line.

In case of maintenance therefore it will be possible to disconnect the actuating unit and to inspect it, possibly in a location more suitable than the installation place.

Moreover in combination with the characteristics of the system, such aspect is particularly advantageous since it is possible to disconnect and inspect an actuating unit, the system detects the breaking on the transmission line and it handles the disconnection of the actuating unit exactly as a normal failure, by restoring the proper operation of the system, isolating the valve associated to the disconnected actuating unit .

In order to optimize the implementation of such characteristic, preferably each actuating unit is composed of an outer case intended to house the processing means for executing the second logic program and which has the second part of the plug connector for the upstream and downstream connection thereof to the transmission line.

Moreover the outer case provides members for the connection to the corresponding valve.

Thus a modular element is obtained, which holds the control electronics of the valve and which can be removed independently from the valve and from the transmission line.

These and other characteristics and advantages of the present invention will be more clear from the following description of some embodiments shown in the annexed drawings wherein:

Figs, la and lb are two schematic diagrams of the system of the present invention;

Figs. 2a to 2e are the execution steps carried out by the system of the present invention for detecting failures on the transmission line;

Figs. 3a and 3b are a possible embodiment of the actuating unit of the system of the present invention. It is specified that the figures shows some embodiments of the system of the present invention, but such embodiments have to be considered merely for illustrative purposes and for better understanding the advantages and characteristics of the system of the present invention.

Such embodiments therefore have not to be considered as a limitation of the inventive concept of the present invention that is to provide a fault tolerant system for operating and controlling valves, namely that guarantees within a relatively short time the functionality of the system in case of failure on the transmission line or of a component.

Figure la shows a schematic block diagram of the system for operating and controlling valves 1 intended to the control of an electrohydraulic system on board a vessel according to the present invention.

Each valve 1 comprises at least one actuating unit 11 for regulating the operation thereof, the valve 1 being electrically connected thereto for receiving control signals.

The system comprises at least two power units 21 and 31, of which a first power unit 21 and a second power unit 31, which are connected to the actuating units 11 of each valve 1.

Particularly the first power unit 21 and the actuating units 11 are connected through a series connection, namely there being provided a single transmission line 4 intended to connect in series the first power unit 21 to the actuating units 11, which transmission line 4 is intended to transmit at least the power signal .

Similarly also the second power unit 31 and the actuating units 11 are connected through a series connection, through the transmission line 4.

As it results from figure la the first power unit 21 and the second power unit 31 are placed at the ends of the transmission line 4.

It is specified that the transmission line 4 can be composed of a single cable connecting the first power unit 21 to the second power unit 31 by connecting each individual actuating unit 11.

As an alternative it is possible to provide the transmission line 4 to be composed of a first transmission line intended to connect in series the first power unit 21 to the actuating units 11 and of a second transmission line intended to connect in series the second power unit 31 to the actuating units 11.

There are further provided breaking members 111, 112, 113, 114, 115, 116, 117, 118, 121 and 131 between each actuating unit 11 and the following one, as well as between the first power unit 21 and the actuating unit 11 directly connected thereto and between the second power unit 31 and the actuating unit 11 directly connected thereto, such that each actuating unit 11 provides an input breaking member 111, 113, 115, 117 and an output breaking member 112, 114, 116, 118 each breaking member being intended to open or close the transmission line 4.

Moreover the first power unit 21 is directly connected to the second power unit 31.

With a particular reference to the figure the first power unit 21 has a connection 5 with the second power unit 31, which can be made in any manner, but preferably it is made through an optical fiber cable.

According to a possible embodiment it is possible to provide a further connection cable 51 between the first power unit 21 and the second power unit 31, intended to transmit a data signal .

As it will be disclosed below such cable allows the ring related to data transmission to be closed.

Morevoer the breaking members 121 and 131 activate or deactivate the connection of the first 21 and second

31 power unit to the following actuating units 11 respectively.

Figure la further shows a preferred embodiment of the system of the present invention, according to which the first power unit 21 is contained in a first main unit 2 which comprises processing means 22 for executing a first logic program.

Similarly the second power unit 31 is contained in a second main unit 3, which comprises processing means

32 for executing the same logic program.

As it results from figure la the first main unit 2 is connected to the second main unit 3 both directly, through the connection 5, and through the connection in series of the actuating units 11.

Advantageously each actuating unit 11 comprises processing means 119 for executing a second logic program. As it clearly results from the arrangement of figure la, the actuating units 11 therefore are intelligent and the logic program loaded therein can be about both the activation/deactivation of the breaking members , and about the detection of operating parameters of the valve 1 to which they are associated.

Thus the main units 21 and 31 are updated instant by instant about the operation of the whole system.

In particular, as it will be disclosed below, the first main unit 21 has information about the operation of the whole system, while the second main unit 31 is a real copy of the unit 21, which is updated istant by instant too, a kind of hot spare for the unit 21.

Since the actuating units interact with the main units 21 and 31 both through power signals and through signals containing information about the operation condition of the system, preferably the transmission line 4 is intended to transmit the power signal and a signal containing information.

A possible embodiment of the system according to the present invention is shown in figure lb.

Such embodiment has all the characteristics described up to now, the breaking members 111, 112, 113, 114, 115, 116, 117, 118, 121, 131 are always provided within each individual actuating unit 11, but each input breaking member is composed of a primary input breaking member 1111 and a secondary input breaking member 1112 and each output breaking member is composed of a primary output breaking member 1121 and a secondary output breaking member 1122. Each actuating unit 11 has a diagnostic unit, that can be integrated into the unit 119, intended to detect the integrity of the transmission line 4.

The diagnostic unit for example can be composed of an electrical analysis circuitry connecting the two secondary breaking members 1112 and 1122.

Obviously the diagnostic unit is connected to the transmission line 4 through the secondary input 1112 and output 1122 breaking members.

Figures 2a to 2e show the operation of the system of the present invention, that is the behavior of the several components of the system depending on the executions of the logic programs loaded into the main units 2 and 3 and the actuating units 11.

With a particular reference to the figures it is specified that, for illustrative simplicity purposes, the symbols, that is circles, showing the several breaking members 111, 112, 113, 114, 115, 116, 117, 118 121 and 131 are considered as open if they are white, that is not filled, as an alternative they are considered as closed if are black.

In figure 2a the system is in the normal operating conditions, the power signal is transmitted on the transmission line 4, the breaking member 121 is closed and it transmits the power signal to the actuating units 11.

The breaking member 131 is open since in the normal operating condition the system is powered only by the first main unit 2.

As an alternative, due to matters of distribution of the load of current and due to safety reasons, it is possible to work with the breaking members 121 and 131 closed, by keeping the powers coming from the power units 21 and 31 separated: half of the valves 1 are powered on one side and the other half on the other side .

Such variant does not change the behavior of the system in case of failure on the transmission line 4, it is simply an operating management choice.

The main unit 2 receives information instant by instant about the operation of the transmission line 4 and of the several components , such to detect the proper operation and the system maintains the configuration of figure 2a till such operation is the same.

Figure 2b shows the behavior of the system at the moment immediately preceding the detection of a failure, denoted by 8, for example a shortcircuit on the transmission line 4.

All the breaking members 111, 112, 113, 114, 115,

116, 117, 118, 131 and 131 are immediately opened and the transmission of the power signal is stopped, isolating the line.

Then, figure 2c, the breaking members 121 and 131 are closed and the power signal is transmitted both by the first main unit 2 and by the second main unit 3 to the directly connected actuating units 11.

Therefore the input breaking members 111 and 117 of such actuating units are also closed, such that the valves 1 associated thereto can be powered and operated.

Afterwards, figure 2d, the following actuating units 11 carry out a diagnostic about the line downstream of the breaking members 112 and 118 and, in case of proper operation of the transmission line 4, they close such breaking members .

Diagnostic preferably is carried out by sending a low voltage signal intended to estimate electrical parameters determing the state of the transmission line.

For example resistance values of the cable can be used, in case of too much high values or of values equal to zero, the system detects the presence of an open circuit or or a shortcircuit downstream of the closed breaking members.

In the particular case of figure 2d the output breaking member 112 is closed and the diagnostic signal is transmitted which detects the absence of downstream failures therefore also the output breaking member 112 and the input breaking member 113 are closed.

On the other side, once the electrical analysis circuitry is inserted, the failure related to the downstream circuit, that is to the actuating unit 11 having the breaking members 115 and 116, is detected.

The breaking member 118 remains open and it does not propagate the power signal of the second main unit 3.

On the other side, figure 2e, the diagnostic proceeds as described above, the breaking members 114 and 116 are closed. Thus the failure remains isolated and the actuating units 11 closest to the failure remain with the breaking members 115 and 118 open.

Anyway such actuating units are powered by the power signal transmitted from the main units 2 and 3 and accordingly they can operate the valves 1 connected thereto .

The same behavior occurs also in the case of the variant embodiment of figure lb.

In this case the step about the closure of the input breaking members 111 and 117, provides to close the secondary input breaking members 1112 and 1172 and the secondary output breaking members 1122 and 1182.

The primary input breaking members 1111 and 1171 are closed and the power signal is transmitted to the actuating units directly connected to the first and second power units.

The diagnostic unit is connected to the transmission line 4 by means of all the secondary breaking members being closed and therefore it can transmit a signal intended to detect the integrity of the transmission line 4 to the following actuating unit .

In case of no failure detection, also the primary output breaking members 1121 and 1181 are closed and the power signal is transmitted to the following actuating unit.

In case the failure is detected the primary output breaking member upstream of the failure remains open, such to isolate the actuating unit following the ailure .

According to a possible embodiment of the system of the present invention, at least the first main unit comprises a display unit and an input/output interface.

The input/output interface allows a user to program the system such to set or modify its behavior and moreover the display unit allows what happens to the several valves 1 to be displayed in real-time.

Thus all the interventions known in the prior art are possible, intended to modify or program the operation of the main units 2 and 3, therefore the system can by automatically and/or manually operated.

Different intervention priority levels can be preferably defined for the system of the present invention.

For example the system architecture can be designed such to provide to the user possible external connections, there is a predetermined control hierarchy for guaranteeing safey of vessels and the priority of the most important controls. Preferably a tested logic is followed, which is organized as follows, in increasing order of priority:

a) Automatic control: under ideal conditions, automation will control the valve system through a graphical monitoring displayed through the display unit. This is the lowest priority level, known also as normal operating mode.

b) External control systems: an external command will have the priority over the automation system. The proper execution of the command has to be guaranteed by disabling the lower control levels.

c) Control panel on board the vessel : such control panels are preferably placed on the main external control panel where it is possible to monitor the state of the system involved in information about the valves. From here it is possible to transmit a command to each valve whose priority is higher than any of the lower levels .

d) ESD (Group command) such command is the highest remote priority level without physically reaching the node. Such level usually is assigned to safety measures that require an emergency intervention on the valve and it has a priority higher than any of the lower levels. It is compulsory to keep such priority active for all the duration of the command such to avoid any possible critical damage to the vessel.

e) local level command: the local command takes place near each individual actuating unit. It directly acts on it and it excludes any type of remote command. Preferably in order to activate such local command the user will have to push "man on site" button, that will return back in the remote position upon its release.

The only way to keep such button on the local position will be through a manual lock.

Figures 3a and 3b show a possible embodiment of the actuating unit 11 of the system according to the present invention.

According to such arrangement each actuating unit

11 is connected to the transmission line 4 through mechanical/electrical connection elements 6 composed of a first part 61 of a plug connector cooperating with a corresponding second part 62 of a plug connector.

The first part 61 is fastened to the ends of the transmission line 4 according to any manner known in the prior art, while the second part 62 is fastened to the actuating unit 11.

As it is clear from the figures annexed to the present patent application, the actuating unit 11 is easily and quickly removable from the transmission line 4, by simply disconnecting the first part 61 from the second part 62.

According to a possible variant embodiment it is possible to provide a sensor intended to detect the connection of the first part 61 to the second part 62, emitting an alarm signal when they are disconnected.

As an alternative or in combination with such characteristic, it is possible to provide a command via software that warns the system that the user disconnects the actuating unit 11 from the transmission line 4.

For safety reasons it is possible to provide two screws 611 engaging into corresponding seats provided in the body of the second part 62 in order to couple the first part 61 to the second part 62.

Figure 3b shows a possible implementation of the first part 61, composed of a cable gland 612 fitted into a support body 613 intended to support a wiring member 614.

The cables of the transmission line 4 are inserted into the cable gland 612 and connected to the member 614 which is coupled to the second part 62.

Finally with a particular reference to figure 3a, each actuating unit 11 is composed of an outer case 7 intended to house the processing means for executing the second logic program, which outer case has the second part 62 of the plug connector for the upstream and downstream connection thereof to the transmission line 4.

Moreover the outer case 7 has members 71 for the connection to the corresponding valve.

Claims

1. System for operating and controlling valves (1) intended to control an electro-hydraulic system on board a vessel, each valve (1) comprising at least one actuating unit (11) for regulating the operation thereof,

the system comprising at least two power units (21, 31) , of which a first power unit (21) and a second power unit (31) , which power units (21, 31) are connected to the actuating units (11) of each valve (1) ,

characterized in that

the actuating units (11) are connected in series with each other by a transmission line (4) , which transmission line (4) is intended to transmit at least the power signal and it comprises a first and a second end, the first power unit (21) being connected in series with said actuating units (11) by the connection to the first one of said two ends of the transmission line (4)

and the second power unit (31) being connected in series to the actuating units (11) by the connection of said second power unit (31) to the second of said ends of the transmission line (4) ,

the first power unit (21) and the second power unit (31) being placed at the ends of the transmission line (4) ,

there being provided breaking members (111, 112, 113, 114, 115, 116, 117, 118, 121, 131) for the transmission line (4) between each actuating unit (11) and the following one, as well as between the first power unit (21) and the actuating unit (11) directly connected thereto and between the second power unit (31) and the actuating unit (11) directly connected thereto, such that each actuating unit (11) provides an input breaking member and an output breaking member, each breaking member (111, 112, 113, 114, 115, 116, 117, 118, 121, 131) being intended to open or close said transmission line (4) ,

and the first power unit (21) being further directly connected to the second power unit (31) .

2. System according to claim 1, wherein said breaking members (111, 112, 113, 114, 115, 116, 117, 118, 121, 131) are provided within each individual actuating unit (11) ,

each input breaking member being composed of a primary input breaking member and a secondary input breaking member and each output breaking member being composed of a primary output breaking member and a secondary output breaking member,

each actuating unit (11) having a diagnostic unit intended to detect the integrity of the transmission line (4) ,

said diagnostic unit being connected to said transmission line (4) through said secondary input and output breaking members .

3. System according to claim 1 or claim 2, wherein the first power unit (21) is contained in a first main unit (2) , which first main unit (2) comprises processing means (22) for executing a first logic program,

the second power unit (31) being contained in a second main unit (3) , which second main unit (3) comprises processing means (32) for executing said first logic program,

the first main unit (2) being connected to the second main unit (3) both directly and through the connection in series of said actuating units (11) .

4. System according to claim 1, wherein each actuating unit (11) comprises processing means (119) for executing a second logic program.

5. System according to claim 3, wherein said transmission line (4) is intended to transmit the power signal and a signal containing information.

6. System according to one or more of the preceding claims, wherein the execution of the first and/or second logic program provides the following steps :

a) detecting possible signal transmission breaks on the transmission line (4) ,

b) opening the breaking members (111, 112, 113, 114, 115, 116, 117, 118, 121, 131) and breaking the power signal ,

c) closing the input breaking member (111) of the actuating unit (11) directly connected to the first power unit (21) and the input breaking member (117) of the actuating unit (11) directly connected to the second power unit (31) and the first power unit (21) and the second power unit (31) sending the power signal to the directly connected actuating units (11) ,

d) the actuating units (11) directly connected to the first and second power units sending a signal to the following actuating unit (11) , intended to detect the integrity of the transmission line (4) ,

e) if breaking is detected isolating the following actuating unit (11) ,

f) if breaking is not detected propagating the power signal to the following actuating unit (11) ,

g) closing the output breaking member (112) of the actuating unit (11) directly connected to the first power unit (21) and the output breaking member (118) of the actuating unit (11) directly connected to the second power unit (31) .

7. System according to claim 6 wherein step c) provides to close the secondary input breaking member of the actuating units (11) directly connected to the first and second power units (21) and the first power unit (21) and the second power unit (31) sending the power signal to the directly connected actuating units (11) ,

step d) providing the actuating units (11) directly connected to the first and second power units to send a signal, through the diagnostic unit, to the following actuating unit (11) , intended to detect the integrity of the transmission line (4) ,

step e) providing to open the primary output breaking member and to close the primary input breaking member if breaking is detected, consequently isolating the following actuating unit (11) , step f) providing to close the primary output breaking members of the actuating units (11) directly connected to the first (21) and second (31) power units if breaking is not detected, consequently propagating the power signal to the following actuating unit (11) .

8. System according to one or more of the preceding claims, wherein at least said first main unit (2) comprises a display unit and an input/output interface .

9. System according to one or more of the preceding claims, wherein said transmission line (4) is composed of a first transmission line intended to connect in series the first power unit (21) to the actuating units (11) and of a second transmission line intended to connect in series the second power unit (31) to the actuating units (11) .

10. System according to one or more of the preceding claims, wherein each actuating unit (11) is connected to said transmission line (4) through mechanical/electrical connection elements composed of a first part (61) of a plug connector (6) cooperating with a corresponding second part (62) of a plug connector, the first part (61) being fastened to the ends of said transmission line (4) and the second part (62) being fastened to the actuating unit (11) .

11. System according to one or more of the preceding claims, wherein each actuating unit (11) is connected to said transmission line (4) through mechanical/electrical connection elements composed alternatively of cable entries IP68 and connection with internal terminal block with screw connection or with plug connector .

12. System according to one or more of the preceding claims, wherein each actuating unit (11) is composed of an outer case (7) intended to house said processing means for executing said second logic program, which outer case (7) has said second part (62) of the plug connector (6) for the upstream and downstream connection thereof to the transmission line (4),

said outer case (7) providing members (71) for the connection to the corresponding valve (1) .