US20120160186A1

US20120160186A1 - Device for controlling the supply of fuel gas to a burner , in particular for water heater appliances

Info

Publication number: US20120160186A1
Application number: US13/326,100
Authority: US
Inventors: Gianpiero Turrin
Original assignee: Sit La Precisa SpA
Current assignee: ITALIANA TECNOMECCANICA SpA Soc; Sit La Precisa SpA
Priority date: 2010-12-27
Filing date: 2011-12-14
Publication date: 2012-06-28
Also published as: ITPD20100393A1; AU2011254070A1; IT1403356B1; CA2762742A1

Abstract

A device for controlling a gas supply to a burner includes a main duct, which is provided with at least one main valve including a valve seat and associated shutter with a control for opening the seat in opposition to a resilient recall member. A pilot duct leads from the main duct to supply a pilot burner, the main duct includes a magnetic thermoelectric safety unit which is manually or automatically armed, acting on the pilot duct to enable gas to flow to the pilot burner when armed. The pilot duct includes a pressure regulator having a shutter with a membrane control, the membrane subject to pressure regulated by the regulator and to a calibration pressure determined in a calibration chamber of the regulator. The device includes a fluid connector between the calibration chamber and the main valve to provide a pressure signal correlated with the gas supply pressure.

Description

FIELD OF THE INVENTION

The present invention relates to a device for controlling the supply of fuel gas to a burner. The invention is applied in particular, although not exclusively, in the sector of devices for the multi-function control of the supply of fuel gases to valve units designed for uses in heating appliances, in particular domestic water heater appliances.

BACKGROUND

In a typical known solution with respect to these devices, a magnetic safety unit with a pilot and a thermocouple is associated with a relative manual arming system and with at least one valve having a mechanical or electrical operator for controlling a gas supply to a main burner directly or indirectly (servo-assisted system).
In these applications, it is also known to provide a pilot duct through which a predetermined flow of gas, correlated with the pressure regulated by a pressure regulator disposed in the pilot duct, is supplied in order to supply the pilot burner flame.
As a result, the flow supplied to the pilot burner is the same during both operation of the pilot burner alone, when the main gas throughput is intercepted, and during operation of the main burner.
It would be preferable, however, to reduce the rate of flow in the rest phases of the pilot burner, when only the pilot flame is ignited, with a view to efficient saving of fuel gas (with the pilot introducing less energy into the system), while at the same time ensuring a higher flow of gas to the pilot to facilitate ignition of the main burner.
The object of the present invention is to provide a device for controlling the supply of fuel gas to a main burner, in particular for water heater appliances, which is structurally and functionally designed to ensure levels of flow to the pilot burner which are appropriate for the various operating stages, with more efficient fuel consumption when only the pilot burner is ignited.
This object is achieved by a device for controlling the supply of fuel gas to a burner embodied in accordance with the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages and features of the present invention will become clear from the following detailed description of preferred embodiments thereof, given with reference to the appended drawings which are provided purely by way of non-limiting example and in which:

FIG. 1 is a diagrammatic view in longitudinal section of a first embodiment of the control device of the invention;

FIG. 2 is a similar view to FIG. 1 of a second embodiment of the control device of the invention;

FIG. 3 is a similar view to the preceding Figures of a third embodiment of the control device of the invention;

FIG. 4 is a similar view to the preceding Figures of a fourth embodiment of the control device of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference, first, to FIG. 1, a device for controlling the supply of fuel gas to a burner of a domestic water heater embodied in accordance with the present invention, is shown overall by 1.
The device 1 comprises a valve unit disposed in a main gas supply duct 2 between a gas inlet section 3 and an outlet section 4 where the gas is supplied to a main burner 4 a.
A main valve, shown overall by 5, is disposed along the main duct 2. The valve 5 comprises a valve seat 5 a associated with a respective shutter 5 b, for instance with membrane control 5 c for the opening of the seat 5 a in opposition to a respective resilient recall member such as a respective spring 5 d.
The valve 5 acts as an on/off valve for the safe closure of the main gas channel, as will be described in detail below.
The valve 5 may be associated with an electrovalve for controlling the servo-assisted circuit, shown by 7, disposed to open and close an auxiliary duct 8 for driving the servo-circuit, which forms the take-up duct for the pressure signal to be transferred to the drive chamber of the servo-circuit. The membrane 5 c acts directly on a control stem 5 e of the shutter 5 b which is in turn urged to close the seat by the spring 5 d.
One side of the membrane 5 c defines a drive chamber 10 which communicates with the main duct 2, upstream of the valve 5, via the duct 8.
More particularly, the duct 8 has a first portion 8 a, extending upstream of the electrovalve 7, and a second portion 8 b, prolonging the first, extending downstream of the electrovalve 7 and communicating with the chamber 10. A throttle 30 is provided in the duct portion 8 b.
The drive chamber 10 is connected to the main duct 2, downstream of the valve seat 5 a of the valve 5, by a respective discharge duct 28 in which a pressure regulator, shown overall by 32, is provided. The regulator is a membrane pressure regulator, known per se, in which one side of the membrane defines a drive chamber 33 communicating, by means of a portion 28 a of the duct 28, with the main duct 2 (downstream of the valve 5) and is also able to intercept the output section of the other portion 28 b of the duct 28 communicating with the drive chamber 10. The opposite side of the membrane is urged by a calibration spring 35 disposed in a chamber open to atmosphere via an opening 36. The pressure regulator 32 is designed to react to the supply pressure variations and to compensate them and return the pressure to a calibration value predetermined by regulation of the spring 35.
The pressure regulator 32 may also be designed with a pressure modulation function, for instance as a modulating regulator of electromagnetic type (by means of a motor, linear actuator) or of pneumatic (membrane) type.
At the location of the electrovalve 7, the relative portion of the duct 8 may be opened and closed at will by an electromagnet 11, of on/off type with resilient recall, acting on a shutter member 12 associated with the throughput section of the duct 8 which may be displaced to and from a position intercepting the throughput section.
The valve unit of the device of the invention comprises an auxiliary gas line, branching from the main line, via which a pilot burner 16 is supplied. The auxiliary line has a pilot duct 16 a which branches from the main duct 2 in order to supply the pilot burner 16.
Starting from the inlet section, in the main duct 2, there is a first section 18′ prolonged by a second section 18″ via an interposed valve seat 18, on which a magnetic thermoelectric safety unit with manual arming 20 (or, as an alternative, with an automatic arming system) acts, this unit including a shutter 18 a which is held in the position opening the seat 18 by the excitation of the magnetic unit generated by the voltage of a thermocouple (not shown) when there is a flame at the pilot burner 16.
The section 18″ communicates with the main duct 2, downstream of the seat 18, and with the drive duct 8.
The section 18″, extending downstream of the seat 18, is also connected with the pilot duct 16 a via an interposed valve seat 20 a.
A shutter 20 b rigid with the control stem 20 c of a knob member 20 d of the magnetic unit acts on the valve seat 20 a.
The drawing shows a top view of the knob 20 d illustrating the operating positions which may be selected (OFF, PILOT, ON).
The knob member 20 d is connected to the actuator stem 20 c to carry out the manual arming of the safety unit, in a manner known per se, in which, in the arming position (PILOT), the ignition of an ignition member (not shown, for instance of piezoelectric type) associated with the pilot burner 16, is simultaneously controlled. The knob 20 d may also be switched to the closed position (OFF) in which the valve seats 18 and 20 a are intercepted by the corresponding shutters of the magnetic safety unit.
A pressure regulator 40, with membrane control, designed to regulate the pressure of the gas and therefore the flow supplied to the pilot burner 16 operates in the pilot duct 16 a.
The pressure regulator 40 includes a servovalve forming a valve seat 40 a cooperating with a shutter shown diagrammatically at 40 b, whose control stem 40 c is rigidly connected to a control membrane 41 for its control. The membrane 41 is subject on one hand to the pressure regulated by the regulator device and on the other hand to a pressure established in a calibration chamber 42 of the regulator and to the resilient force of a spring 43.
According to the invention, a connection duct 45 is provided and brings the calibration chamber 42 into fluid communication with a section of the main duct 2 downstream of the valve 5, i.e. in a valve portion subject to a gas pressure when the shutters 12 and 5 are in the open position.
As an alternative, it is possible for the connection duct 45 to bring the chamber 42 into fluid communication with a section of the portion 8 b of the duct 8 disposed downstream of the electrovalve 7.
The pressure signal downstream of the valve 5 (or in the above-mentioned alternative version, in the section 8 b of the drive duct), is supplied to the calibration chamber 42 via the duct 45.
It is possible, as a result of the provision of the connection duct 45, to obtain two separate pressure (and therefore flow) levels in the gas supplied via the pilot duct.
A first pressure level is generated in the pilot duct when the valve 5 is in the closed condition (with the valve 7 closed).
At this stage, as no gas is passing through the electrovalve 7, no pressure correlated with the supply pressure is determined in the main duct downstream of the valve 5 (or, in the above-mentioned alternative version, in the portion 8 b of the duct 8) and the regulator therefore determines a pressure correlated solely with the resilient force of the spring 43 which causes a first level of supply flow to the pilot burner to maintain the pilot flame (the main burner is not activated).
The subsequent opening of the valve seat 5, by excitation of the electrovalve 7, causes, in the main duct downstream of the valve 5 (or, in the above-mentioned alternative version, in the portion 8 b of the duct 8), a pressure signal equal to or correlated with the supply pressure in the main duct, which signal, transferred by means of the duct 45 to the calibration chamber 42, determines a second pressure level regulated by the regulator, greater than the first level, and such as to enable the ignition of the main burner to which the gas flow is supplied after opening of the main duct 2.
It is thus possible to obtain a so-called ‘two-stage’ pilot burner 16, with a first reduced flow level designed solely to maintain the pilot burner flame, and a second higher flow level designed to ignite the main burner.
FIG. 2 shows a second embodiment of the device of the invention, in which details similar to those of the previous embodiment bear the same reference numerals.
In this embodiment, the control device is applied to a valve of thermostat type, of the so-called ‘thermo-mechanical thermostat’ type, in which the valve seat 5 a obtained in the main duct 2 is associated with a corresponding shutter 5 b controlled by a thermo-mechanical actuator 50. A valve unit of this type is disclosed in Italian Patent Application PD2000A000138, in the name of the Applicants, whose specification is understood to be fully included here for any detail which is not described in detail below.
The above-mentioned actuator comprises a member 51 sensitive to water temperature variations which is disposed in contact with the water to be heated and is connected in operation to the shutter 5 b of the valve. As a result of the thermal expansion of this member, a displacement correlated with the variation of the water temperature is generated, by a bi-stable elastic device 52, with respect to the control stem 5 c of the shutter, as a result of which the shutter is caused to close the corresponding valve seat to intercept the flow of gas when a predetermined temperature value is exceeded.
In this embodiment, the device of the invention connects the calibration chamber 42, by means of the duct 45, with a section of the main duct 2 disposed downstream of the valve seat 5 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above.
FIG. 3 shows a third embodiment of the device of the invention, in which details similar to those of the previous embodiments bear the same reference numerals.
In this embodiment, the control device is applied to a valve unit in which a pair of main servo- valves 5, 6 are provided in cascade with one another and a draught switch 55 of pneumatic type is disposed in the combustion fume discharge duct 56. A valve unit of this type is disclosed in Italian Patent Application PD2010A000385, in the name of the Applicants, whose specification is understood to be fully included here for any detail which is not described in detail below.
Similarly to the previous embodiment, the device of the invention connects the calibration chamber 42, by means of the duct 45, with the section of the main duct 2 disposed downstream of the valve seat 6 a of the servo-valve 6 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above.
FIG. 4 shows a fourth embodiment of the device of the invention, in which details similar to those of the previous embodiments bear the same reference numerals.
This embodiment differs from the preceding embodiment chiefly in that it includes a draught switch 55 with a motor-driven actuator 60, as shown diagrammatically in the corresponding Figure. Similarly to the previous embodiment, the calibration chamber 42 of the regulator is connected, via the duct 45, with the section of the main duct 2 disposed downstream of the valve seat 6 a of the servo-valve 6 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above.
The invention thus achieves the above-mentioned objects and also achieves the advantages listed with respect to known solutions. It should in particular be noted that it is possible, as a result of the invention, substantially to reduce the energy introduced into the system by the pilot burner during the “rest” stage in which no gas passes through the main duct in the direction of the main burner.
A device for controlling the supply of fuel gas to a burner, in particular for water heater appliances

SPECIFICATION

The present invention relates to a device for controlling the supply of fuel gas to a burner in accordance with the features set out in the preamble of claim 1. The invention is applied in particular, although not exclusively, in the sector of devices for the multi-function control of the supply of fuel gases to valve units designed for uses in heating appliances, in particular domestic water heater appliances.
In a typical known solution with respect to these devices, a magnetic safety unit with a pilot and a thermocouple is associated with a relative manual arming system and with at least one valve having a mechanical or electrical operator for controlling a gas supply to a main burner directly or indirectly (servo-assisted system).
In these applications, it is also known to provide a pilot duct through which a predetermined flow of gas, correlated with the pressure regulated by a pressure regulator disposed in the pilot duct, is supplied in order to supply the pilot burner flame.
As a result, the flow supplied to the pilot burner is the same during both operation of the pilot burner alone, when the main gas throughput is intercepted, and during operation of the main burner.
It would be preferable, however, to reduce the rate of flow in the rest phases of the pilot burner, when only the pilot flame is ignited, with a view to efficient saving of fuel gas (with the pilot introducing less energy into the system), while at the same time ensuring a higher flow of gas to the pilot to facilitate ignition of the main burner.
The object of the present invention is to provide a device for controlling the supply of fuel gas to a main burner, in particular for water heater appliances, which is structurally and functionally designed to ensure levels of flow to the pilot burner which are appropriate for the various operating stages, with more efficient fuel consumption when only the pilot burner is ignited.
This object is achieved by a device for controlling the supply of fuel gas to a burner embodied in accordance with the appended claims.
Other advantages and features of the present invention will become clear from the following detailed description of preferred embodiments thereof, given with reference to the appended drawings which are provided purely by way of non-limiting example and in which:
FIG. 1 is a diagrammatic view in longitudinal section of a first embodiment of the control device of the invention;
FIG. 2 is a similar view to FIG. 1 of a second embodiment of the control device of the invention;
FIG. 3 is a similar view to the preceding Figures of a third embodiment of the control device of the invention;
FIG. 4 is a similar view to the preceding Figures of a fourth embodiment of the control device of the invention.
With reference, first, to FIG. 1, a device for controlling the supply of fuel gas to a burner of a domestic water heater embodied in accordance with the present invention, is shown overall by 1.
The device 1 comprises a valve unit disposed in a main gas supply duct 2 between a gas inlet section 3 and an outlet section 4 where the gas is supplied to a main burner 4 a.
A main valve, shown overall by 5, is disposed along the main duct 2. The valve 5 comprises a valve seat 5 a associated with a respective shutter 5 b, for instance with membrane control 5 c for the opening of the seat 5 a in opposition to a respective resilient recall means such as a respective spring 5 d.
The valve 5 acts as an on/off valve for the safe closure of the main gas channel, as will be described in detail below.
The valve 5 may be associated with an electrovalve for controlling the servo-assisted circuit, shown by 7, disposed to open and close an auxiliary duct 8 for driving the servo-circuit, which forms the take-up duct for the pressure signal to be transferred to the drive chamber of the servo-circuit. The membrane 5 c acts directly on a control stem 5 e of the shutter 5 b which is in turn urged to close the seat by the spring 5 d.
One side of the membrane 5 c defines a drive chamber 10 which communicates is with the main duct 2, upstream of the valve 5, via the duct 8.
More particularly, the duct 8 has a first portion 8 a, extending upstream of the electrovalve 7, and a second portion 8 b, prolonging the first, extending downstream of the electrovalve 7 and communicating with the chamber 10. A throttle 30 is provided in the duct portion 8 b.
The drive chamber 10 is connected to the main duct 2, downstream of the valve seat 5 a of the valve 5, by a respective discharge duct 28 in which a pressure regulator, shown overall by 32, is provided. The regulator is a membrane pressure regulator, known per se, in which one side of the membrane defines a drive chamber 33 communicating, by means of a portion 28 a of the duct 28, with the main duct 2 (downstream of the valve 5) and is also able to intercept the output section of the other portion 28 b of the duct 28 communicating with the drive chamber 10. The opposite side of the membrane is urged by a calibration spring 35 disposed in a chamber open to atmosphere via an opening 36. The pressure regulator 32 is designed to react to the supply pressure variations and to compensate them and return the pressure to a calibration value predetermined by regulation of the spring 35.
The pressure regulator 32 may also be designed with a pressure modulation function, for instance as a modulating regulator of electromagnetic type (by means of a motor, linear actuator) or of pneumatic (membrane) type.
At the location of the electrovalve 7, the relative portion of the duct 8 may be opened and closed at will by an electromagnet 11, of on/off type with resilient recall, acting on a shutter member 12 associated with the throughput section of the duct 8 which may be displaced to and from a position intercepting the throughput section.
The valve unit of the device of the invention comprises an auxiliary gas line, branching from the main line, via which a pilot burner 16 is supplied. The auxiliary line has a pilot duct 16 a which branches from the main duct 2 in order to supply the pilot burner 16.
Starting from the inlet section, in the main duct 2, there is a first section 18′ prolonged by a second section 18″ via an interposed valve seat 18, on which a magnetic thermoelectric safety unit with manual arming 20 (or, as an alternative, with an automatic arming system) acts, this unit including a shutter 18 a which is held in the position opening the seat 18 by the excitation of the magnetic unit generated by the voltage of a thermocouple (not shown) when there is a flame at the pilot burner 16.
The section 18″ communicates with the main duct 2, downstream of the seat 18, and with the drive duct 8.
The section 18″, extending downstream of the seat 18, is also connected with the pilot duct 16 a via an interposed valve seat 20 a.
A shutter 20 b rigid with the control stem 20 c of a knob member 20 d of the magnetic unit acts on the valve seat 20 a.
The drawing shows a top view of the knob 20 d illustrating the operating positions which may be selected (OFF, PILOT, ON).
The knob member 20 d is connected to the actuator stem 20 c to carry out the manual arming of the safety unit, in a manner known per se, in which, in the arming position (PILOT), the ignition of an ignition member (not shown, for instance of piezoelectric type) associated with the pilot burner 16, is simultaneously controlled. The knob 20 d may also be switched to the closed position (OFF) in which the valve seats 18 and 20 a are intercepted by the corresponding shutters of the magnetic safety unit.
A pressure regulator 40, with membrane control, designed to regulate the pressure of the gas and therefore the flow supplied to the pilot burner 16 operates in the pilot duct 16 a.
The pressure regulator 40 includes a servovalve forming a valve seat 40 a cooperating with a shutter shown diagrammatically at 40 b, whose control stem 40 c is rigidly connected to a control membrane 41 for its control. The membrane 41 is subject on one hand to the pressure regulated by the regulator device and on the other hand to a pressure established in a calibration chamber 42 of the regulator and to the resilient force of a spring 43. According to the invention, a connection duct 45 is provided and brings the calibration chamber 42 into fluid communication with a section of the main duct 2 downstream of the valve 5, i.e. in a valve portion subject to a gas pressure when the shutters 12 and 5 are in the open position.
As an alternative, it is possible for the connection duct 45 to bring the chamber 42 into fluid communication with a section of the portion 8 b of the duct 8 disposed downstream of the electrovalve 7.
The pressure signal downstream of the valve 5 (or in the above-mentioned alternative version, in the section 8 b of the drive duct), is supplied to the calibration chamber 42 via the duct 45.
It is possible, as a result of the provision of the connection duct 45, to obtain two separate pressure (and therefore flow) levels in the gas supplied via the pilot duct.
A first pressure level is generated in the pilot duct when the valve 5 is in the closed condition (with the valve 7 closed).
At this stage, as no gas is passing through the electrovalve 7, no pressure correlated with the supply pressure is determined in the main duct downstream of the valve 5 (or, in the above-mentioned alternative version, in the portion 8 b of the duct 8) and the regulator therefore determines a pressure correlated solely with the resilient force of the spring 43 which causes a first level of supply flow to the pilot burner to maintain the pilot flame (the main burner is not activated).
The subsequent opening of the valve seat 5, by excitation of the electrovalve 7, causes, in the main duct downstream of the valve 5 (or, in the above-mentioned alternative version, in the portion 8 b of the duct 8), a pressure signal equal to or correlated with the supply pressure in the main duct, which signal, transferred by means of the duct 45 to the calibration chamber 42, determines a second pressure level regulated by the regulator, greater than the first level, and such as to enable the ignition of the main burner to which the gas flow is supplied after opening of the main duct 2.
It is thus possible to obtain a so-called ‘two-stage’ pilot burner 16, with a first reduced flow level designed solely to maintain the pilot burner flame, and a second higher flow level designed to ignite the main burner.
FIG. 2 shows a second embodiment of the device of the invention, in which details similar to those of the previous embodiment bear the same reference numerals.
In this embodiment, the control device is applied to a valve of thermostat type, of the so-called ‘thermo-mechanical thermostat’ type, in which the valve seat 5 a obtained in the main duct 2 is associated with a corresponding shutter 5 b controlled by a thermo-mechanical actuator 50. A valve unit of this type is disclosed in Italian Patent Application PD2000A000138, in the name of the Applicants, whose specification is understood to be fully included here for any detail which is not described in detail below.
The above-mentioned actuator comprises a member 51 sensitive to water temperature variations which is disposed in contact with the water to be heated and is connected in operation to the shutter 5 b of the valve. As a result of the thermal expansion of this member, a displacement correlated with the variation of the water temperature is generated, by a bi-stable elastic device 52, with respect to the control stem 5 c of the shutter, as a result of which the shutter is caused to close the corresponding valve seat to intercept the flow of gas when a predetermined temperature value is exceeded.
In this embodiment, the device of the invention connects the calibration chamber 42, by means of the duct 45, with a section of the main duct 2 disposed downstream of the valve seat 5 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above. FIG. 3 shows a third embodiment of the device of the invention, in which details similar to those of the previous embodiments bear the same reference numerals.
In this embodiment, the control device is applied to a valve unit in which a pair of main servo- valves 5, 6 are provided in cascade with one another and a draught switch 55 of pneumatic type is disposed in the combustion fume discharge duct 56. A valve unit of this type is disclosed in Italian Patent Application PD2010A000385, in the name of the Applicants, whose specification is understood to be fully included here for any detail which is not described in detail below.
Similarly to the previous embodiment, the device of the invention connects the calibration chamber 42, by means of the duct 45, with the section of the main duct 2 disposed downstream of the valve seat 6 a of the servo-valve 6 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above.
FIG. 4 shows a fourth embodiment of the device of the invention, in which details similar to those of the previous embodiments bear the same reference numerals.
This embodiment differs from the preceding embodiment chiefly in that it includes a draught switch 55 with a motor-driven actuator 60, as shown diagrammatically in the corresponding Figure. Similarly to the previous embodiment, the calibration chamber 42 of the regulator is connected, via the duct 45, with the section of the main duct 2 disposed downstream of the valve seat 6 a of the servo-valve 6 with respect to the direction of the flow of gas, thus obtaining the two-stage pilot function described above.
The invention thus achieves the above-mentioned objects and also achieves the advantages listed with respect to known solutions. It should in particular be noted that it is possible, as a result of the invention, substantially to reduce the energy introduced into the system by the pilot burner during the “rest” stage in which no gas passes through the main duct in the direction of the main burner.

Claims

1. A device for controlling the supply of fuel gas to a burner comprising:

a main duct for supplying the gas between an inlet section and an outlet section,

the main duct being provided with at least one main valve including a respective valve seat associated with a corresponding shutter with a respective control for opening of the seat in opposition to a respective resilient recall member,

a pilot duct for supplying a pilot burner leading from the main duct upstream of at least the one main valve,

the main duct being provided, upstream of at least the one main valve, with a magnetic thermoelectric safety unit with a manually armed switch or with an automatic arming system, which acts on the pilot duct to enable the gas to flow to the pilot burner when the unit is armed,

the pilot duct being provided with a pressure regulator having a shutter with a membrane control, the membrane being subject on one hand to the pressure regulated by the regulator and on the other hand to a calibration pressure determined in a calibration chamber of the regulator, a calibration spring being provided in the chamber and acting on the membrane, and

a fluid connector between the calibration chamber of the pressure regulator and at least the one main valve, in order to supply to the calibration chamber a pressure signal correlated with the gas supply pressure when supplied to the main duct such that the pressure regulated by the regulator can be regulated at least to a first level, when there is no gas supply in the main duct, and to a second level, greater than the first level, when gas is being supplied in the main duct, the flow of gas supplied to the pilot duct being correlated with the respective levels of the pressure signal supplied to the calibration chamber.

2. The device according to claim 1, wherein the fluid connector comprises a connection duct extending between the calibration chamber and a section of the main supply duct downstream of the valve seat of at least the one main valve with respect to the direction of flow of the gas, the pressure signal supplied to the calibration chamber corresponding to the gas supply pressure obtained through the main valve.

3. The device according to claim 1, wherein at least the one main valve comprises a respective control electrovalve with a mechanical or electric operator to control opening/closing of the main valve, the electrovalve configured to open/close a drive duct of a respective servo-assisted drive circuit so as indirectly to control, by the membrane control, the respective shutter of the corresponding valve, the respective duct of the drive circuit bringing the main duct into fluid communication with a respective drive chamber of the main valve, one side of the membrane of the membrane control being subject to pressure in the respective drive chamber, the fluid connector comprising a duct connecting the calibration chamber of the pressure regulator and a section of the drive duct of the valve, the section being disposed between the electrovalve and the drive chamber.

4. The according to claim 2, wherein the pressure signal supplied to the calibration chamber of the regulator, by the connection duct, is correlated with a regulated gas supply pressure supplied to the burner when the main valve is in an open position.

5. The device according to claim 3, wherein the pressure signal supplied to the calibration chamber of the regulator, by the connection duct, is correlated with a regulated gas supply pressure supplied to the burner when the main valve is in an open position.