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Title:
A METHOD FOR SIGNALLING A LOSS OF LIQUID IN A PORTION OF HYDRAULIC CIRCUIT SUPPLIED BY A SUPPLY OF LIQUID
Document Type and Number:
WIPO Patent Application WO/2015/170246
Kind Code:
A1
Abstract:
A method for signalling a loss of liquid in a portion of hydraulic circuit supplied by a supply of liquid, and a relative system. The method, starting from a condition in which the supply of liquid to the portion of hydraulic circuit is interrupted, comprises verifying periodically if the pressure value of the liquid contained in the portion of hydraulic circuit is lower than a minimum pressure value, and if this is true enables supplying liquid to the portion of hydraulic circuit and carrying out following steps: calculating the overall volume of the liquid which has transited through the portion of hydraulic circuit and if equal to or higher than a maximum volume value, then interrupting supply of liquid to the portion of hydraulic circuit, signalling a loss of liquid and halting the carrying out of the method; periodically verifying whether the flow rate of the liquid transiting through the portion of hydraulic circuit is lower than a minimum flow rate value or if the pressure value of the liquid contained in the portion of hydraulic circuit is greater than a maximum pressure value, and if this is true interrupting supply of liquid to the portion of hydraulic circuit and repeating the method.

Inventors:
TOSTI MATTEO (IT)
LUPINI PAOLO (IT)
CECCHINI STEFANO (IT)
Application Number:
PCT/IB2015/053266
Publication Date:
November 12, 2015
Filing Date:
May 05, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TOSTI MATTEO (IT)
LUPINI PAOLO (IT)
CECCHINI STEFANO (IT)
International Classes:
E03B7/07; G01M3/28
Foreign References:
US20040050790A12004-03-18
KR100942811B12010-02-18
US20040050790A12004-03-18
Other References:
See also references of EP 3140464A1
Attorney, Agent or Firm:
DALL'OLIO, Daniele et al. (Via Delle Armi 1, Bologna, IT)
Download PDF:
Claims:
CLAIMS

1) A method for signalling a leakage of liquid in a portion of a hydraulic circuit (1) supplied by a liquid supply, which portion of hydraulic circuit (1) is arranged upstream of one or more users (U), wherein the method, starting from a condition in which the liquid supply to the portion of hydraulic circuit (1) is interrupted, is characterised in that it comprises a first step that includes periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1) is lower than a minimum pressure value, and if this is true carrying out a second step which includes enabling supply of liquid to the portion of hydraulic circuit (1 ) and carrying out following steps:

- a third step which includes calculating the overall volume of the liquid which has passed through the portion of hydraulic circuit (1) and if it is equal to or greater than a maximum volume value, carrying out a fourth step which includes interrupting the supply of liquid to the portion of hydraulic portion (1), signalling a loss of liquid and stopping the carrying out of the method;

- a fifth step including periodically verifying if the flow rate value of the liquid transiting through the portion of hydraulic circuit (1) is lower than a minimum flow rate value or periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1) is greater than a maximum pressure value, and if this is true, carrying out a sixth step which includes interrupting supply of liquid to the portion of hydraulic circuit (1) and repeating the method.

2) The method of claim 1 , wherein if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value, the method comprises a seventh step which includes verifying if in a first predetermined time interval the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is reduced by at least a first entity, and if this is true, carrying out an eighth step which includes signalling a loss of liquid and stopping the carrying out of the method.

3) The method of claim 2, wherein the seventh step includes verifying if the variation in the pressure value of the liquid in the portion of hydraulic circuit (1) in the first predetermined time interval is greater than a minimum value of pressure variation.

4) The method of claim 2, wherein the seventh step includes verifying if the variation in the pressure value of the liquid in the portion of hydraulic circuit (1) in the first predetermined time interval is lower than a maximum value of pressure variation.

5) The method of any one of the preceding claims from 2 to 4, wherein if in the seventh step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) reduced by the at least a first entity in the first predetermined time interval, before carrying out the eighth step, the method comprises following steps:

- a ninth step including incrementing a counter;

- a tenth step including verifying if the value of the counter is equal to a limit value, and if this is true, carrying out the eighth step otherwise repeating the method.

6) The method of claim 5, wherein if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value, the method comprises an eleventh step which includes verifying if a time that has passed since a last time the ninth step has been carried out is shorter than a second predetermined time interval; if in the eleventh step the time that has passed since the last time in which the ninth step has been carried out is equal to or greater than the second predetermined time interval, zeroing the counter and repeating the method, otherwise, if in the seventh step the liquid pressure value in the portion of hydraulic circuit (1) is reduced by the at least a first entity of the first predetermined time interval, carrying out the ninth step and the tenth step.

7) The method of claim 1 , wherein if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to the minimum pressure value, the method comprises a twelfth step which includes verifying if the volume value of the liquid that has transited through the portion of hydraulic circuit (1) is lower than a minimum volume value, and if this is true, carrying out a thirteenth step which includes signalling a loss of liquid and stopping the carrying out of the method otherwise repeating the method.

8) The method of any one of the preceding claims, wherein following the second step the method comprises a step of periodically verifying if in a third predetermined time interval the liquid flow rate value transiting through the portion of hydraulic circuit (1) is reduced by at least a second entity or the pressure value of the liquid transiting through the portion of hydraulic circuit (1) increases by at least a third entity, and if this is true zeroing the already- calculated overall volume of the liquid that has transited through the portion of hydraulic circuit (1) and repeating the method successively of the second step.

9) The method of any one of the preceding claims, wherein if in the third step the overall volume of the liquid that has transited towards the portion of hydraulic circuit (1) is equal to or greater than the maximum volume value, before carrying out the fourth step the method comprises, in order, following steps:

- storing a first flow rate value of the liquid transiting through the portion of hydraulic circuit (1);

- interrupting supply of liquid to the portion of hydraulic circuit (1) and, after a fourth predetermined time interval, enabling supply of liquid to the portion of hydraulic circuit (1);

- verifying if the liquid flow rate value transiting through the portion of hydraulic circuit (1) is lower than the first liquid flow rate value, and if this is true zeroing the already-calculated overall volume of the liquid that has transited through the portion of hydraulic circuit (1) and repeating the method successively of the second step otherwise carrying out the fourth step.

10) A method for signalling a loss of liquid in a portion of a hydraulic circuit (1) supplied by a liquid supply, which portion of hydraulic circuit (1) is arranged upstream of one or more users (U), wherein the method, starting from a condition in which the liquid supply to the portion of hydraulic circuit (1 ) is interrupted, is characterised in that it comprises a first step that includes periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value; if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value, carrying out a second step which includes enabling supply of liquid to the portion of hydraulic circuit (1 ) and a fifth step including periodically verifying if the flow rate value of the liquid transiting through the portion of hydraulic circuit (1 ) is lower than a minimum flow rate value or periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is greater than a maximum pressure value, and if this is true, carrying out a sixth step which includes interrupting liquid supply to the portion of hydraulic circuit (1 ) and repeating the method; if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value, carrying out one of the following steps, alternative to one another:

- if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value, the method comprises a seventh step which includes verifying if in a first predetermined time interval the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is reduced by at least a first entity, and if this is true, carrying out an eighth step which includes signalling a loss of liquid and stopping the carrying out of the method;

- if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to the minimum pressure value, carrying out a twelfth step which includes verifying if the volume value of the liquid that has transited through the portion of hydraulic circuit (1 ) is lower than a minimum volume value, and if this is true, carrying out a thirteenth step which includes signalling a loss of liquid and stopping the carrying out of the method otherwise repeating the method.

11) The method of claim 10, wherein the seventh step includes verifying if the variation in the pressure value of the liquid in the portion of hydraulic circuit (1) in the first predetermined time interval is greater than a minimum value of pressure variation.

12) The method of claim 10, wherein the seventh step includes verifying if the variation in the pressure value of the liquid contained in the portion of hydraulic circuit (1) in the first predetermined time interval is lower than a minimum value of pressure variation.

13) A system (100) for signalling a loss of liquid in a portion of hydraulic circuit (1) supplied by a supply of liquid, comprising: a valve (2) that is mobile between an open position (A), for enabling supply of liquid to the portion of hydraulic circuit (1), and a closed position (B), for interrupting supply of liquid to the portion of hydraulic circuit (1 ); first detecting means (3) arranged downstream of the valve (2), for detecting a pressure of liquid contained in the portion of hydraulic circuit (1); signalling means (7) for signalling a liquid loss; a control unit (5) connected to the valve (2), to the first detecting means (3) and to the signalling means (7) for receiving the data detected by the first detecting means (3) and for commanding the valve (2), between the open position (A) and the closed position (B), and the signalling means (7); the system (100) being characterised in that it comprise a tank (6) of liquid in fluid communication with the portion of hydraulic circuit (1). 14) The system (100) of claim 13, comprising second detecting means (4) arranged downstream of the valve (2) for detecting the liquid flow rate value which transits through the portion of hydraulic circuit (1) or the value of a volume which transits through the portion of hydraulic circuit (1 ).

Description:
A METHOD FOR SIGNALLING A LOSS OF LIQUID IN A PORTION OF HYDRAULIC CIRCUIT SUPPLIED BY A SUPPLY OF LIQUID

FIELD OF THE INVENTION

The present invention relates to technical sector concerning loss of liquids in hydraulic circuits. In particular, the present invention relates to a method for signalling a loss of liquid in a portion of hydraulic circuit supplied by a supply of liquid (i.e. a liquid source) and a relative system.

DESCRIPTION OF THE PRIOR ART

A portion of a hydraulic circuit is generally supplied by a liquid supply and arranged upstream of one or more users: for example, the portion of hydraulic circuit can be a domestic or industrial hydraulic plant arranged downstream of the water counter.

Document US 2004/050790 discloses a method for signalling a loss of liquid in a portion of hydraulic circuit supplied by a supply of liquid. The system comprises: a valve mobile between an open position, to enable supply of liquid to the portion of hydraulic circuit, and a closed position, for interrupting supply of liquid to the portion of hydraulic circuit; a pressure sensor arranged downstream of the valve to detect the pressure of the liquid contained in the portion of hydraulic circuit; a LED for signalling, when lit, a loss of liquid from the portion of hydraulic circuit; a control unit which receives the data detected by the pressure sensor and which commands the valve, between the open position and the closed position, and the lighting/extinguishing of the LED.

The above known system for signalling a loss of liquid includes, starting from a condition in which the valve is in the open position, the control unit periodically comparing the data detected by the pressure sensor with a reference pressure value. In a case in which, for example, the pressure of the liquid detected by the pressure sensor is lower than the reference pressure value, it is presumed that there is a loss of liquid in the portion of hydraulic circuit: the control unit commands the movement of the valve into the closed position and the lighting of the LED for signalling the loss of liquid.

SUMMARY OF THE INVENTION

In the light of the foregoing, the aim of the present invention is to disclose a method for signalling a loss of liquid in a portion of hydraulic circuit that provides an alternative to what is described in the foregoing, and a relative system.

The above aim has been obtained with a method in accordance with, respectively claim 1 and claim 8 and with a system according to claim 13.

BRIEF DESCRIPTION OF THE DRAWINGS Specific embodiments of the invention will be described in the following part of the present description, according to what is set out in the claims and with the aid of the accompanying tables of drawings, in which:

- figures 1 and 2 illustrate an embodiment of a system of the present invention, able to implement an embodiment of the method, also an object of the present invention, in which the valve is respectively in the closed position and the open position;

- figures 3 and 4 illustrate a further embodiment of a system object of the present invention, able to implement a further embodiment of the method, also object of the present invention, in which the valve is respectively in the closed position and the open position;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying tables of drawings, (1 ) denotes in its entirety a portion of a hydraulic circuit supplied by a liquid supply and arranged upstream of one or more users (U). The portion of hydraulic circuit (1) can be, for example, a domestic or industrial hydraulic plant arranged downstream of the water counter. In a first embodiment, the method, starting from a condition in which the liquid supply to the portion of hydraulic circuit (1 ) is interrupted, comprises a first step that includes periodically verifying (continuously or with a predetermined frequency) if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value, and if this is true carrying out a second step which includes enabling supply of liquid to the portion of hydraulic circuit (1 ) and carrying out following steps:

- a third step which includes calculating the overall volume of the liquid which has passed (i.e. transited over time) through the portion of hydraulic circuit (1) and if it is equal to or greater than a maximum volume value, carrying out a fourth step which includes interrupting the supply of liquid to the portion of hydraulic portion (1 ), signalling a loss of liquid and stopping the carrying out of the method;

- a fifth step including periodically verifying (continuously or with a predetermined frequency) if the flow rate value of the liquid transiting through the portion of hydraulic circuit (1 ) (i.e. the instantaneous volume value which transits through the portion of hydraulic circuit (1 )) is lower than a minimum flow rate value or periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is greater than a maximum pressure value, and if this is true, carrying out a sixth step which includes interrupting supply of liquid to the portion of hydraulic circuit (1 ) and repeating the method starting from the first step.

The above method includes starting from a condition in which the supply of liquid to the portion of hydraulic circuit (1 ) is interrupted. This supply of liquid is enabled only in a case in which the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value: this condition is determined by effect of either a request for liquid by one or more users (U) or by effect of a loss of liquid.

In a case where the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value, following a request for liquid by a user (U), the method includes continuing supply of liquid to the portion of hydraulic circuit (1) as long as the request for liquid by the user (U) continues, i.e. up to when the flow rate value of the liquid transiting through the portion of hydraulic circuit (1) is equal to or greater than the minimum flow rate value or up to when the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or lower than the maximum pressure value.

In a case where request for liquid by a user (U) is such that the overall volume of the liquid that has transited through the portion of hydraulic liquid (1) is equal to or greater than the maximum volume value, a loss of liquid is signalled as the maximum volume value has been reached: for example, a user might have left a stopcock on or it has simply reached the limit and this is signalled.

In a case in which, on the other hand, the pressure value of the liquid in the portion of hydraulic circuit (1) is lower than a minimum value caused by a loss of liquid (for example breakage of a tube), the method comprises continuing supply of liquid to the portion of hydraulic circuit (1 ) up to when the overall volume of the liquid that has transited through the portion of hydraulic circuit (1 ) is equal to or greater than the maximum volume value.

Thus the disclosed method enables signalling a liquid loss by exploiting a calculation of the overall volume of liquid that has transited through the portion of hydraulic circuit (1). In particular, the calculation of the overall volume is made possible by the fact that each time the method is repeated starting from the first step, the calculation of the overall volume newly begins, starting from zero.

With reference to the known system, as described in the preamble of the present patent application, it signals a loss of liquid by comparing the pressure value of the liquid contained in the portion of hydraulic circuit with a reference pressure value. Supposing, for example, that there are four users downstream of the portion of hydraulic circuit, it is clear that the minimum pressure of the liquid in the portion of hydraulic circuit occurs when all the users require liquid. Therefore the known system will have to set the reference pressure value so that it is lower than the minimum pressure, so as to ensure that all the users can require liquid at the same time without the valve being commanded into the closed position. A liquid loss is not necessarily of an entity such as to determine a drop in the pressure below the reference pressure, especially if it has been set at a low value as a high number of users is known downstream of the portion of hydraulic circuit. The known method therefore might not be able to detect a loss of liquid.

The proposed method is advantageously more reliable than the known method, as it is based on a calculation of the overall volume in the above- described way.

The third step and the fifth step are preferably carried out at the same time. In this case, for example, the third step is carried out continuously over time and the fifth step is carried out periodically at the same time as the third step.

The third step and the fifth step are alternatively carried out alternatingly. In this case, for example, the third step might be carried out for a predetermined time interval (for example 10 seconds) and, following the predetermined time interval of 10 seconds, in a case in which the fourth step has not been carried out, the carrying out of the third step is interrupted and the fifth step begins for a further predetermined time interval (for example 5 seconds). In a case in which the sixth step has not been carried out, after the predetermined time interval of 5 seconds, the fifth step is interrupted and the third step is newly commenced, and so on.

The minimum pressure value, the maximum volume value, the minimum flow rate value and the maximum pressure value can each be set manually or automatically. In particular, the maximum volume value can be set automatically on the basis of the preceding consumption of liquid (on the historical basis of the liquid collections). The maximum volume value can be a fixed value over time or variable over time. It is implicit that in a case in which there are not losses of liquid and liquid is not requested by one or more users (U), the volume of liquid transiting through the portion of hydraulic circuit (1) is nil. For this reason, the fifth step preferably includes verifying if the flow value of the liquid that has transited through the portion of hydraulic circuit (1) is nil.

In the first step, for each outlet of liquid from the portion of hydraulic circuit (1), by effect of a collection by a user or a loss of liquid, a reduction of the pressure in the portion of hydraulic circuit (1 ) is verified. As described above, if liquid is not requested by a user (U) and the pressure value of the liquid contained in the portion of hydraulic circuit (1) is lower than the minimum pressure value, the drop in pressure is imputable to a loss of liquid: this loss of liquid is of such an entity as to determine a drop in pressure of the liquid contained in the portion of hydraulic circuit (1) below the minimum pressure value and, therefore the loss of liquid is of a medium/large entity. However, the fact that the pressure of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value does not confirm that there are no liquid losses. In fact, there might be liquid losses of such small entities (such as for example a drip or a leak) so as not to determine the drop in pressure in the liquid in the portion of hydraulic circuit (1) below the minimum pressure value. In particular, specific method embodiments proposed (as described in the following) are able to detect, before reaching the minimum pressure value or on reaching the limit, the presence of the liquid losses of modest entity.

In particular, preferably, if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value, the method comprises a seventh step which includes verifying if in a first predetermined time interval the pressure value of the liquid contained in the portion of hydraulic circuit (1) is reduced by at least a first entity (i.e. the difference between the pressure of the liquid contained in the portion of hydraulic circuit (1) calculated at the end of the first predetermined time interval is lower than the pressure in the first predetermined interval), and if this is true, carrying out an eighth step which includes signalling a loss of liquid and stopping the carrying out of the method. If the seventh step is negative, repeat the method starting from the first step.

The embodiment of the method advantageously enables detecting the losses of modest entity. In fact, in a case in which there is a modest loss, this does not determine the drop in pressure in the liquid in the portion of hydraulic circuit (1) below the minimum pressure value but determines a slow and moderate drop in the pressure of the liquid contained in the portion of hydraulic circuit (1 ); the method advantageously enables detecting the slow drop in the pressure of the liquid contained in the portion of hydraulic circuit (1) and signalling losses of even modest entity.

According to a specific embodiment, the seventh step preferably includes verifying if the variation in the pressure value of the liquid in the portion of hydraulic circuit (1) in the first predetermined time interval is greater than a minimum value of pressure variation. In this specific embodiment, it is therefore evaluated whether in the first predetermined time interval (for example in the order of minutes/hours) there is a variation in pressure at least equal to the minimum pressure variation value.

In accordance with a further specific embodiment, the detecting of an eventual loss of liquid of modest entity is based on the calculation of the pressure derivative. In particular, the seventh step preferably includes verifying if the variation in the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) in the first predetermined time interval is lower than a minimum value of pressure variation. In fact, in a case of a loss of a modest entity the derivative of the pressure is significantly lower than that obtained in a case where a user takes liquid: in this case, if the velocity with which the pressure decreases is lower than the maximum value of pressure variation, the method is able to attribute the reduction of pressure to a loss of liquid of modest entity rather than to a collection of liquid by a user.

If in the seventh step the liquid pressure value in the portion of hydraulic circuit (1 ) is reduced by the at least a first entity of the first predetermined time interval, before carrying out the eighth step the method preferably comprises following steps: a ninth step including incrementing a counter (the counter is predisposed to count the events relating to liquid loss of modest entity); a tenth step which includes verifying if a value of the counter is equal to a limit value, and if this is true, carrying out the eighth step otherwise repeating the method starting from the first step.

In a case where liquid losses of a modest entity are verified, the use of the counter advantageously enables signalling the liquid losses of modest entity only when they are verified in a greater number than the set limit value.

If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value, the method preferably comprises an eleventh step which includes verifying if a time that has passed since a last time the ninth step has been carried out is shorter than a second predetermined time interval. If in the eleventh step the time that has passed since the last time in which the ninth step has been carried out is equal to or greater than the second predetermined time interval, zeroing the counter (i.e. the counter predisposed for counting the events relating to liquid loss of modest entity) and repeating the method starting from the first step, otherwise, if in the seventh step the liquid pressure value in the portion of hydraulic circuit (1 ) is reduced by the at least a first entity in the first predetermined time interval, carrying out the ninth step and the tenth step.

The eleventh step enables zeroing the counter in a case in which the time that has passed since the last time in which the ninth step has been carried out is equal to or greater than the second predetermined time interval. In this way, if a sufficiently long time has passed since the last time in which a liquid loss of a modest entity has been detected (i.e. a time equal to or greater than the second predetermined time interval), the count of the liquid loss restarts from zero. In the case of liquid loss of modest entity, the method advantageously enables not signalling it as liquid loss of the sporadic events of liquid loss of small entity. The eleventh step is preferably carried out before the seventh step. In this case the seventh step is carried out only in a case in which the time that has passed since the last time in which the ninth step has been carried out is less than the second predetermined time interval. Alternatively the eleventh step can be carried out at the same time as the seventh step.

If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value, the method preferably comprises a step which includes verifying if the volume of liquid that has transited through the portion of hydraulic circuit (1 ) is lower than a minimum volume value. If in the seventh step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is reduced by the at least a first entity in the first predetermined time interval, and the volume of liquid that has transited through the portion of hydraulic circuit (1 ) is lower than the minimum volume value, carrying out the eighth step otherwise repeating the method. This embodiment is a further variant with the aim of detecting losses of small entity.

In the following a further embodiment of the method for signalling losses of liquid of modest entity is described. This embodiment is alternative to the embodiments described in the foregoing.

In accordance with the further embodiment of the method for detecting losses of modest entity, if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to the minimum pressure value, the method preferably comprises a twelfth step which includes verifying if the volume value of the liquid that has transited through the portion of hydraulic circuit (1 ) is lower than a minimum volume value, and if this is true, carrying out a thirteenth step which includes signalling a loss of liquid and stopping the carrying out of the method otherwise repeating the method starting from the first step.

The twelfth step enables, in the case of liquid losses of a modest entity, signalling a liquid loss only in a case in which as well as the drop in pressure the volume of liquid that has transited through the portion of hydraulic circuit (1) is lower than the minimum volume value (it can be set manually or automatically).

It is implicit that in a case in which there are not losses of liquid and liquid is not requested by one or more users (U), the volume of liquid that has transited through the portion of hydraulic circuit (1) is nil. For this reason, the twelfth step preferably includes verifying if the volume of liquid that has transited through the portion of hydraulic circuit (1) is nil.

This embodiment can include a step, if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to the minimum pressure value and before carrying out the thirteenth step, incrementing a relative counter and verifying if it is equal to a relative limit value. If the above is confirmed, the thirteenth step is carried out.

All the above-described embodiments can include, in a case in which the counter is not equal to the limit value, enabling supply to the portion of hydraulic circuit (1) for a certain time so as to return the pressure of the liquid contained in the portion of hydraulic circuit (1) to above the minimum pressure value and to repeat the method starting from the first step.

When the method carries out the eighth step or the thirteenth step which include signalling a loss of liquid (in the case of losses of small entity), a person can intervene to deactivate the alarm signal (for example an optical or acoustic signal) and verify the cause thereof. In a case where after a certain period of time the person has not deactivated the alarm signal, the supply of liquid to the portion of hydraulic circuit (1) is blocked until a manual reset is performed by the person.

Following the second step the method preferably comprises a step of periodically verifying if in a third predetermined time interval the liquid flow rate value transiting through the portion of hydraulic circuit (1) is reduced by at least a second entity or the pressure value of the liquid transiting through the portion of hydraulic circuit (1) increases by at least a third entity, and if this is true zeroing the already-calculated overall volume of the liquid that has transited through the portion of hydraulic circuit (1 ) and repeating the method from the second step onwards.

The second step includes enabling the supply of liquid to the portion of hydraulic circuit (1 ) on in a case in which the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value: this condition is determined, as already mentioned in the foregoing, in a case in which there is a request for liquid by one or more users (U) or there is a loss of liquid. It is supposed that a liquid loss determines a liquid flow which transits through the portion of hydraulic circuit (1) that is constant over time, or possibly which grows.

Thus, in a case in which the second predetermined liquid volume value which transits through the portion of hydraulic circuit (1 ) is reduced by at least a second entity or the pressure value of the liquid transiting through the portion of hydraulic circuit (1 ) increases by at least a third entity, a loss of liquid in the portion of hydraulic circuit (1 ) can be excluded, and be imputed to a request for liquid by one or more users (U).

For example, supposing having four users (U) downstream of the portion of hydraulic circuit (1 ) and that two of these are requesting liquid, as soon as the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than the minimum pressure value, liquid supply is enabled. At this point the calculation of the overall volume begins. However, if a user (U) ceases requesting liquid, the liquid flow rate value transiting is probably not lower than the minimum flow rate (this condition occurs presumably if no user (U) requests liquid) but a drop in flow rate is detected: in this case the step of zeroing the already-calculated overall volume of the liquid that has transited through the portion of hydraulic circuit (1 ) is carried out, and the method is repeated successively to the second step. If in the third step the overall volume of the liquid that has transited through the portion of hydraulic circuit (1) is equal to or greater than the maximum volume value, then preferably before carrying out the fourth step the method preferably comprises, in order, the following steps: memorising a first liquid flow rate value which transits through the portion of hydraulic circuit (1 ); interrupting the supply of liquid of the portion of hydraulic circuit (1) and, after a fourth predetermined time interval, enabling the supply of liquid to the portion of hydraulic circuit (1 ); verifying if the liquid flow rate value transiting through the portion of hydraulic circuit (1) is lower than the first liquid flow rate value, and if this is true zeroing the already-calculated overall volume of the liquid that has transited through the portion of hydraulic circuit (1) and repeating the method successively to the second step otherwise carrying out the fourth step.

This embodiment of the method advantageously enables, in a case in which there is a user requesting an amount of liquid such as to reach the maximum liquid volume, preventing a signalling a loss of liquid which in effect has not been verified by modulating (done by a person) the liquid flow rate transiting through the portion of hydraulic circuit (1).

For example, supposing that liquid from a tap has been requested for a long period of time, it might occur that the volume of the liquid that has transited through the portion of hydraulic circuit (1) is equal to or greater than the maximum volume value. In this case the method interrupts the supply of liquid for a fourth predetermined time interval and if the person closes the tap for a greater time than the fourth predetermined time interval (known to him or her) the method is able to comprehend that the user device is requesting liquid and there is not a loss of liquid. Consequently the method newly enables supply of liquid and does not signal any liquid loss.

In the case of loss of liquid of a medium/large entity, when the fourth step is verified and a loss of liquid is signalled, the method preferably includes blocking supply of liquid until a user resets it manually.

A further preferred embodiment of the method of the present invention described, alternative to the embodiments of the method described above. The same reference numerals are used to denote the same steps.

The method, starting from a condition in which the liquid supply to the portion of hydraulic circuit (1 ) is interrupted, comprises a first step that includes periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value. If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is lower than a minimum pressure value, carrying out a second step which includes enabling supply of liquid to the portion of hydraulic circuit (1 ) and a fifth step including periodically verifying if the flow rate value of the liquid transiting through the portion of hydraulic circuit (1 ) is lower than a minimum flow rate value or periodically verifying if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is greater than a maximum pressure value, and if this is true, carrying out a sixth step which includes interrupting liquid supply to the portion of hydraulic circuit (1 ) and repeating the method starting from the first step. If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value, the method includes carrying out one of the following steps, alternative to one another: - if the pressure value of the liquid contained in the portion of hydraulic circuit

(1 ) is equal to or greater than the minimum pressure value, the method comprises a seventh step which includes verifying if in a first predetermined time interval the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is reduced by at least a first entity, and if this is true, carrying out an eighth step which includes signalling a loss of liquid and stopping the carrying out of the method;

- if the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) is equal to the minimum pressure value, carrying out a twelfth step which includes verifying if the volume value of the liquid that has transited through the portion of hydraulic circuit (1 ) is lower than a minimum volume value, and if this is true, carrying out a thirteenth step which includes signalling a loss of liquid and stopping the carrying out of the method otherwise repeating the method.

This embodiment of the method advantageously enables signalling loss o liquid of modest entity. The fact that the pressure of the liquid contained in the portion of hydraulic circuit (1 ) is equal to or greater than the minimum pressure value does not enabling confirming that there are no liquid losses: there might be liquid losses of such low amounts (such as for example a drip) so as not to determine the drop in pressure in the liquid in the portion of hydraulic circuit (1) below the minimum pressure value.

The above embodiment of the method advantageously enables detecting the losses of modest entity. This method is clearly alternative with respect to the method of the known system. As mentioned, the known system enables detecting only losses of significant entity: in particular it enables detecting liquid losses which are such as to determine a drop in the pressure below the reference pressure, wherein reference pressure has been set at a low value as a high number of users is downstream of the portion of hydraulic circuit.

According to a specific embodiment, the seventh step preferably includes verifying if the variation in the pressure value of the liquid in the portion of hydraulic circuit (1) in the first predetermined time interval is greater than a minimum value of pressure variation. In this specific embodiment, it is evaluated whether in the first predetermined time interval (for example in the order of seconds) there is a variation in pressure at least equal to the minimum pressure variation value.

In accordance with a further specific embodiment, the detecting of an eventual loss of liquid of modest entity is based on the calculation of the pressure derivative. In particular, the seventh step preferably includes verifying if the variation in the pressure value of the liquid contained in the portion of hydraulic circuit (1 ) in the first predetermined time interval is lower than a minimum value of pressure variation. In fact, in a case of a loss of a modest entity the derivative of the pressure is significantly lower than that obtained in a case where a user takes liquid: in this case, if the velocity with which the pressure decreases is lower than the maximum value of pressure variation, the method is able to attribute the reduction of pressure to a loss of liquid of modest entity rather than to a collection of liquid by a user. If in the seventh step the liquid pressure value in the portion of hydraulic circuit

(1) is reduced by the at least a first entity in the first predetermined time interval, before carrying out the eighth step, the method preferably comprises following steps: a ninth step including incrementing a counter (the counter is predisposed to count the events relating to liquid loss of modest entity); a tenth step which includes verifying if a value of the counter is equal to a limit value, and if this is true, carrying out the eighth step otherwise repeating the method starting from the first step. In a case where liquid losses of a modest entity are verified, the use of the counter enables signalling the liquid losses of modest entity only in a moment in which they are verified in a greater number than the set limit value.

If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value, the method preferably comprises an eleventh step which includes verifying if a time that has passed since a last time the ninth step has been carried out is shorter than a second predetermined time interval. If in the eleventh step the time that has passed since the last time in which the ninth step has been carried out is equal to or greater than the second predetermined time interval, zeroing the counter (i.e. the counter predisposed for counting the events relating to liquid loss of modest entity) and repeating the method starting from the first step, otherwise, if in the seventh step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is reduced by the at least a first entity in the first predetermined time interval, carrying out the ninth step and the tenth step.

The eleventh step enables, in a case in which the time that has passed since the last time in which the ninth step has been carried out is equal to or greater than the second predetermined time interval, zeroing the counter. In this way, if a sufficiently long time has passed since the last time in which a liquid loss of a modest entity has been detected (i.e. a time equal to or greater than the second predetermined time interval) the count of the liquid loss restarts from zero. In the case of liquid loss of modest entity, the method advantageously enables not signalling as a liquid loss those sporadic events of liquid loss of small entity.

The eleventh step is preferably carried out before the seventh step. In this case the seventh step is carried out only in a case in which the time that has passed since the last time in which the ninth step has been carried out is less than the second predetermined time interval. Alternatively the eleventh step can be carried out at the same time as the seventh step.

If in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to or greater than the minimum pressure value, the method can preferably comprise a step which includes verifying if the volume of liquid that has transited through the portion of hydraulic circuit (1) is lower than a minimum volume value. If in the seventh step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is reduced by the at least a first entity in the first predetermined time interval and the volume of liquid that has transited through the portion of hydraulic circuit (1) is lower than the minimum volume value, the eighth step can be carried out otherwise the method can be repeated. This embodiment is a further variant with the aim of detecting losses of small entity.

Further, the method can comprise, if in the first step the pressure value of the liquid contained in the portion of hydraulic circuit (1) is equal to the minimum pressure value, before carrying out the thirteenth step, incrementing a relative counter and verifying if it is equal to a relative limit value. If the above is confirmed, the thirteenth step is carried out, otherwise the portion of hydraulic circuit (1) is supplied in such a way as to return the pressure of the liquid above the minimum pressure value and the method is repeated.

When the method carries out the eighth step or the thirteenth step which include signalling a loss of liquid (in the case of losses of small entity), a person can intervene to deactivate the alarm signal (for example an optical or acoustic signal) and verify the cause thereof. In a case where after a certain period of time the person has not deactivated the alarm signal, the supply of liquid to the hydraulic circuit (1) is blocked until a manual reset is performed by the person.

With reference to figures 1 and 2, a first embodiment is described of a system for signalling a loss of liquid in a portion of hydraulic circuit (1) served by a supply of liquid. This first embodiment is able to implement some embodiments of the method as described above: in particular, it is able to implement the embodiments of the method which do not require detection of the value of the flow rate of the liquid which transits through the portion of hydraulic circuit (1).

This embodiment of the system (100) comprises: a valve (2) mobile between an open position (A), for enabling supply of liquid to the portion of hydraulic circuit (1), and a closed position (B) for interrupting supply of liquid to the portion of hydraulic circuit (1); first detecting means (3) arranged downstream of the valve (2) so as to detect the pressure of the liquid contained in the portion of hydraulic circuit (1); signalling means (7) for signalling a liquid loss; a control unit (5) connected to the valve (2), to the first detecting means (3) and to the signalling means (7), for receiving the data detected by the first detecting means (3) and for commanding the valve (2) between the open position (A) and the closed position (B), and the signalling means (7). The system ( 00) further comprises a tank (6) of liquid in fluid communication with the portion of hydraulic circuit (1).

The use of a tank (6) of liquid advantageously enables an instantaneous response of the system ( 00) on request of liquid by one or more users (U).

In a further embodiment (figures 3 and 4) the system (100) can comprise second detecting means (4) arranged downstream of the valve (2) for detecting the liquid flow rate value which transits through the portion of hydraulic circuit (1) or the value of a volume which transits through the portion of hydraulic circuit (1). This embodiment of the system (100) is able to implement any embodiment of the method of the present invention.

With reference to figures 1 and 3, the system (100) is illustrated in which the valve (2) is in the closed position (B). In this case, a request for liquid by the user (U) is in a first instant satisfied by the liquid contained in the portion of hydraulic circuit (1) and in the tank (6) (figures 1 and 3). The use of the tank (6) of liquid advantageously enables an instantaneous response of the system (100) on request of liquid by one or more users (U). Subsequently, at an instant in which the pressure value of the liquid contained in the portion of hydraulic circuit (1) is lower than the minimum pressure value, the control unit (5) commands the valve (2) into the open position (A) so that supply of liquid to the portion of hydraulic circuit (1) is enables (figures 2 and 4).

The valve (2) can be a mono-stable or bi-stable valve (2). The first detecting means (3) can be a pressure sensor or a mechanical pressure switch. The second detecting means (4) are embodied by a volumetric meter or a flow rate meter.

The second detecting means (4) are preferably arranged in proximity of the valve (2). The tank (6) (for example a bladder tank) is preferably arranged upstream of the second detecting means (4).

The signalling means (7) can be of an acoustic and/or a visual type. Further, the signalling means (7) can be differentiated on the basis of type of liquid loss (losses of medium/large entity or losses of modest entity). The control unit (5) can be supplied by means of a battery internal of the control unit (5).

The system (100) might comprise a display for displaying data (for example the historical data relating to losses of liquid or the graph relating to the progress of the volume of liquid dispensed over time). The system (100) can further comprise input means (for example pulsating) for entering parameters of the system (100) by a user person and/or for resetting the system (100) following a block due to signalling of a liquid loss.