Valve for pressurized fluids

Abstract

Valve for pressurized fluids comprising a valve body (2) including an outflow pipe, a valve seat which is arranged along said outflow pipe, a first shutter (5) and a second shutter (6) configured thereby opening and closing said valve seat and a driving member (7) connected to said second shutter and configured to actuate said first shutter and said second shutter thereby opening and closing said valve seat; wherein said first shutter defines a compensation chamber therein a portion of said second shutter is received thereby supporting said first shutter with sliding capacity along an actuation axis, said first shutter including a communication channel which connects said compensation chamber with an outlet (1b), said driving member being configured to move said second shutter in the opening direction, releasing said communication channel and, once said communication channel has been opened, pulling said first shutter in the opening direction.

Description

[0001] Valve for pressurized fluids

[0002] DESCRIPTION

[0003] Technical scope

[0004] The present invention concerns a valve for pressurized fluids, in particular valves for pressurized H2.

[0005] Technological background

[0006] In the field of hydrogen storage and distribution systems, the technical difficulties arising from the need to operate at high operating pressures are known.

[0007] An aspect that may be critical concerns in particular the opening and closing phases of shut-off valves intended for use in distribution systems or in association with hydrogen tanks and cylinders or other fluids intended to be stored at high pressure. The valves for such applications, such as for example that described in CN114321391A, typically include an inlet pipe, an outlet pipe and a shutter capable of intercepting a passage between the two pipes.

[0008] The shutter is actuated by means of a rod which is connected to a control member, for example manual, i.e. formed by a rotating handwheel.

[0009] The high operating pressures make the conditions under which the sealing members must operate particularly critical. In particular, the seal at the rod to which the control member is connected must be able to withstand the stresses deriving from the action of the flow of pressurized liguid during its passage between inlet and outlet, as well as those that are determined during the opening and closing of the shutter.

[0010] A known solution provides for dividing the shutter into a main shutter and an auxiliary shutter that opens and closes an orifice in the main shutter.

[0011] Some examples of this type of valves are reported in US3624753A, US2015 / 267837A1, US3211419A.

[0012] Another aspect, described in patent US6491056B2, concerns the fractionation of the fluid flow rate between inlet and outlet of a valve, to differentiate the flow between a test phase and a phase of use of a fire-fighting device. In this case, the auxiliary shutter allows the passage of a reduced fluid flow rate, thereby allowing the operation of the fire-fighting device to be verified without wasting the fluid for extinguishing.

[0013] Therefore, in the technical field of reference, there remains the need to have a valve for pressurized fluids, in particular for H2, which is improved both from the point of view of the conformation of the shutter and the characteristics of the flow it determines, and of the materials used to make the actuator.

[0014] Description of the invention The problem underlying the present invention is to make available a valve for pressurized liquids that is structurally and functionally designed to overcome, at least in part, the limits set out above with reference to the prior art.

[0015] Within the scope of this problem, it is an object of the invention to provide a valve for pressurized fluids that is easy to implement, within a relatively simple embodiment.

[0016] A further object of the invention is to make available a valve whose use does not cause excessive stresses on the sealing elements and in general on the movable components of the valve.

[0017] Another object of the present invention is to provide a reliable and durable valve. Finally, an additional object of the invention is to provide a valve that is particularly stable during use.

[0018] In a first aspect thereof, this problem is at least in part solved and one or more of these objects are at least in part achieved by a valve for pressurized fluids comprising a valve body including an inlet, an outlet and an outflow duct putting said inlet in hydraulic communication with said outlet.

[0019] The valve further comprises a valve seat, which is arranged along said outflow pipe, a first shutter and a second shutter. Preferably, the first shutter and / or the second shutter is / are configured so as to open and close said valve seat by moving away and towards respectively, along an actuation axis, an abutment surface defined in said valve seat.

[0020] The valve comprises an driving member, which is preferably connected to said second shutter. Preferably, the driving member is configured to actuate said first shutter and / or said second shutter thereby opening and closing said valve seat.

[0021] Preferably, said first shutter defines a compensation chamber therein a portion of said second shutter is received thereby supporting said first shutter with sliding capacity along said actuation axis.

[0022] Preferably, the first shutter includes a communication channel which connects the compensation chamber with the outlet of the valve.

[0023] The communication channel advantageously defines a passage section with extension that is smaller than a corresponding passage section of said outflow duct in the region of said valve seat.

[0024] The driving member is preferably configured to move said second shutter in the opening direction, freeing said communication channel and, once said communication channel is opened, pulling said first shutter in the opening direction, away from said abutment surface.

[0025] Preferably, said first shutter comprises at least one passage configured to put said compensation chamber in hydraulic communication with said inlet.

[0026] Advantageously, the valve according to the present invention allows to pass from a condition of no flow through the outflow duct of the valve to a flow condition, passing through a compensation phase in which the opening movement takes place with respect to surfaces of reduced extension, thus allowing to limit the forces involved in this phase. The torque that must be applied to obtain the opening of the valve seat is therefore reduced compared to the known solutions, consequently reducing the stresses deriving from the opening cycles of the valve.

[0027] The sliding capacity of the first shutter with respect to the second shutter allows to then obtain the complete opening of the valve seat once a balance of the pressures has been reached within the valve seat, thereby limiting the forces necessary to open the valve to the only frictions of contact between the actuation parts.

[0028] The presence of the passage configured to put the compensation chamber in hydraulic communication with the inlet allows to optimally balance the pressures in the valve seat when opening the valve.

[0029] The present invention may also have one or more of the following preferred features in addition to those mentioned above.

[0030] Preferably, the first shutter comprises a main body, which is preferably substantially cylindrical and therein said compensation chamber is defined, and a shutter end which tapers towards a vertex defined at said actuation axis.

[0031] These shapes make it possible to optimise the overall dimensions, make the structure easy to assemble and optimise the flows during the opening phases of the valve.

[0032] Preferably, said communication channel is positioned at said vertex, making the structure more symmetrical and allowing an isostatic constraint system to be provided.

[0033] In some embodiments, the second shutter comprises a connection end which is rotatably connected to said driving member.

[0034] Thanks to this feature, the rotation of the shutter during opening and closing is avoided, thus limiting wear and the stresses in general.

[0035] Preferably, the driving member is connected to said valve body by means of a thread so as to convert a rotational motion of said driving member into a translational motion along said actuation axis. Advantageously, said connection end is configured to disengage said second shutter from the rotational motion of said driving member during said translational motion along said actuation axis.

[0036] In this way, the actuation of the valve can be carried out simply by means of a handwheel, a generic device or tool or by means of a motorized rotating actuation system.

[0037] Preferably, said second shutter comprises a rod and a head, said head includes a closure element which is configured to close said communication channel. This structure also contributes to improving the isostaticity of the closure system.

[0038] In some embodiments said rod and said connection end have a substantially cylindrical shape, said connection end having a diameter greater than said rod and, wherein said rod comprises a shoulder which is integral therewith, which extends in an annular manner around said rod.

[0039] Preferably, a sealing element is present.

[0040] In some embodiments the valve seat comprises a first actuation section wherein the driving member is movable. Preferably said sealing element is connected to said driving member so that said driving member is sealingly housed in said first actuation section.

[0041] The sealing element is preferably positioned between said shoulder and said first shutter. Preferably, said sealing element is movable along said actuation axis, between said shoulder and said first shutter. In some embodiments, the sealing element comprises a striking body, which is arranged near said shoulder and a pair of lips which extend in a divergent manner from said abutment member, thereby a pressurized fluid in said valve seat tends to urge said lips away from each other.

[0042] In this way, the characteristics of the valve, in particular the presence of the two shutters, can be suitably exploited to guarantee an optimal seal during opening.

[0043] According to a further aspect, said sealing element comprises a reinforcement element which is arranged between said lips. Preferably, the abutment member and said lips are made from plastics material and said reinforcement element is made from metal material.

[0044] Thanks to these characteristics it is possible to improve the strength of the sealing element and in general the reliability of the valve.

[0045] Preferably, said first shutter is elastically deformable thereby allowing the insertion of a portion of said second shutter in said compensation chamber.

[0046] Preferably, said portion of said second shutter is said head of said second shutter. Advantageously, the first shutter is elastically deformable for the said first shutter to fit in said second shutter by insertion of the head in the compensation chamber. In some embodiments the first shutter is made from plastics material. In this way, the realization of the valve and the assembly operation thereof can be simplified.

[0047] In some embodiments the passage is in the form of a slot which extends substantially parallel to said actuation axis.

[0048] In this way, a simple realization of the structure is allowed, which can therefore be advantageously obtained in plastic material.

[0049] Preferably, the pressurized fluid considered is pressurized H2, in the gaseous and / or liquid state depending on the thermal condition.

[0050] Preferably, said valve is usable at high pressures, in particular at pressures comprised between 0 bar and 300 bar or 400 bar, alternatively between 50 bar and 300 bar or 400 bar, more preferably between 100 bar and 300 bar, even more preferably at 300 bar.

[0051] The characteristics and advantages of the invention will become clearer from the detailed description of a preferred embodiment example thereof, illustrated by way of non-limiting example, with reference to the appended drawings wherein:

[0052] - figure 1 is a perspective view of a valve according to the invention;

[0053] - figure 2 is an exploded perspective view of a valve according to figure 1;

[0054] - figure 3 is a view in transparency of said figure 2;

[0055] - figure 4 is a side view of an exploded section of said valve;

[0056] - figure 5 is a perspective sectional view of an exploded view of a detail of said valve;

[0057] - figure 6 is a sectional side view of said valve;

[0058] - figures 6a, 6b and 6c are three detailed views, according to a cross section, of the valve seat of the valve of the present invention;

[0059] - figure 7 is a perspective view of an exploded view of a detail of said valve; and

[0060] - figure 8 is a perspective view in transparency of a detail of said valve.

[0061] With reference to the annexed figures, 1 indicates overall a valve in accordance with the present invention.

[0062] Figure 1 shows a valve 1 for pressurized fluids which typically comprises a valve body 2 including an outflow pipe 3, visible e.g. in figure 4, which is extended between an inlet la, which is arranged to be hydraulic connected with a container containing a pressurized fluid, such as for example a gas cylinder, and an outlet lb which is arranged to be hydraulic connected with a device apt to receive said fluid.

[0063] In some embodiments, as can be observed for example in figure 6, the outlet lb comprises two portions: a first portion 11a, configured to connect the valve 1, for example, with a piping, and a second portion lib, thereatan abutment surface for a valve shutter is defined, as will be illustrated in greater detail below. Preferably, both portions have a cylindrical shape, with the first portion 11a having a diameter greater than the second portion lib. The outlet lb may also comprise a connecting portion 11c which is arranged between said first 11a and said second lib portion.

[0064] The inlet la is configured as an inlet channel 111b, preferably also cylindrical in shape. The inlet channel 111b is configured to let the valve 1 be connected to a coupling adapter of a pressurized container, e.g. either by a threaded connection or by placing it around the inlet channel 111b at the outer walls 112b thereof.

[0065] The valve 1 comprises, in its most general embodiments, a valve body 2 housing an outflow pipe 3, extending between said inlet la and said outlet lb, and a valve seat 4 arranged in the outflow pipe 3 itself. Note that the valve seat 4 defines a first zone 3a of the outflow pipe 3 upstream of the valve seat 4 and a second zone 3b downstream of the valve seat 4.

[0066] The valve 1 also comprises a first shutter 5 and a second shutter 6 configured thereby opening and closing said valve seat 4, and an driving member 7 apt to move with respect to said valve seat 4 along an axis X, also indicated below as the actuation axis X. The driving member 7 allows shifting the first and the second shutter 5, 6 to open and close said valve seat 4 stopping against an abutment surface 12, in the ways described in greater detail below.

[0067] As visible in figures 4, 5 and 6, the first shutter 5 defines a compensation chamber 5a that houses a portion of said second shutter 6, also identified below as head 6b, providing a movement capacity of the latter along the axis X. In other words, the connection between the first shutter 5 and the second shutter 6 is made so that the first shutter 5 can make limited movements with respect to the second shutter 6 along the direction defined by the axis X.

[0068] As can be observed from figures 4, 5 and 6, the first shutter 5 comprises a main body 5e, which is substantially cylindrical and therein a compensation chamber 5a is defined, and a shutter end 5d which tapers towards a vertex, the vertex being defined at said actuation axis X. Advantageously, the shutter end 5d has a substantially conical shape.

[0069] The first shutter 5 further defines a communication channel 5b which connects the compensation chamber 5a with said second zone 3b, i.e. that downstream of the valve seat 4.

[0070] The communication channel 5b is preferably positioned at the vertex of said conical shutter end 5d. In some embodiments the compensation chamber 5a has a discoidal shape, with rounded outer walls. An access portion 5g extending between the compensation chamber 5a and a base 5h of the main body 5e is also defined on the main body 5e. Preferably, the access portion 5g also has a substantially cylindrical shape.

[0071] As can be observed from figures 4, 5, 6, 6a, 6b and 6c, in preferred embodiments the second shutter 6 comprises a rod 6a and a head 6b with a frustoconical shape, which is housed in the compensation chamber 5a and configured to close the communication channel 5b.

[0072] In some embodiments, the head 6b has a decreasing diameter towards the abutment surface 12. The rod 6a has a cylindrical shape with a diameter that is smaller than that of the head 6b at a connecting section between the head 6b and the rod 6a.

[0073] Preferably, the head 6b includes a closure element 6c, in the form of a protrusion, which is configured to be partially inserted into said communication channel 5b to close it when said head 6b abuts on said first shutter 5.

[0074] According to the embodiments reported in the figures, the closure element 6c is a conical element, integral with said head 6b which has a greater base diameter equal to the diameter of said communication channel 5b, so as to ensure its closure when the valve 1 is closed.

[0075] Advantageously, the frustoconical shape of the head 6b facilitates the insertion of the head 6b into the first shutter 5 through the access portion 5g.

[0076] Note that the second shutter 6, once the head 6b, or more generally a relative connection portion, is housed in the compensation chamber 5a, can perform limited movements along the actuation axis X inside the compensation chamber 5a. The movements are however constrained by the first shutter 5.

[0077] In fact, the compensation chamber 5a comprises an abutment 5c apt to stop the head 6b when the second shutter 6 moves along the actuation axis X.

[0078] This allows the first shutter 5 to be pulled by translation of the driving member 7 to fully open the valve seat 4.

[0079] The abutment 5c is preferably made as an annular recess wherein a head portion 6b is housed, the head portion 6b being distal from the end of the head 6b intended to abut on the first shutter 5. Once the head portion 6b abuts the main body 5e at the abutment 5c, the second shutter 6 is movable along a second stretch, moving the first shutter 5 along the actuation axis X and fully opening the valve 1.

[0080] In some embodiments the first shutter 5 is made from plastics material.

[0081] Preferably, the first shutter 5 further comprises at least one passage 5f, and more preferably a plurality of passages, which are made on the main body 5e configured to put the compensation chamber in hydraulic communication with the inlet la, or more generally with the first zone 3a.

[0082] Preferably, the main body 5e comprises an outer side surface 57.

[0083] The passages 5f can be made in the form of a slot and can extend substantially parallel to the actuation axis X.

[0084] For this purpose, slots can be defined in said first shutter 5 which put the chamber 5a in hydraulic communication with the first zone 3a.

[0085] Furthermore, the passages 5f, preferably in the form of a slot, may extend up to the base 5h of the first shutter 5.

[0086] In preferred embodiments, such as the one illustrated in the figures, the passages 5f do not extend on the shutter end.

[0087] Preferably, the passages 5 are in the form of through slots which extend from the outer side surface 57 of the main body 5e up to the compensation chamber 5a and possibly up to the base 5h.

[0088] More generally, therefore, when the first shutter 5 is resting at the abutment surface 12, e.g. in the configuration of figure 6, the inlet la and the outlet lb can be put in hydraulic communication through the communication channel 5b, the compensation chamber 5a and the passages 5f.

[0089] Figures 6, 6a, 6b and 6c illustrate the different configurations that the two shutters assume during the opening of the valve.

[0090] In the closed valve condition, the communication channel 5b is obstructed by the second shutter 6.

[0091] Still from figure 6 it is possible to observe that the communication channel 5b defines a cross section with extension that is smaller than a corresponding cross section of the outflow duct 3.

[0092] The opening and closing of the valve is carried out through the driving member 7 which advantageously is configured to move with respect to said valve seat 4 between a closed position, in which the first shutter 5 closes the outflow pipe 3, leaving only the passage through the communication channel 5b defined, which is however in turn closed by the second shutter 6, preventing a flow of fluid in the outflow pipe 3, and an open position, wherein this passage is allowed.

[0093] This open position, illustrated in figure 6b, is however achieved through two operating phases.

[0094] In a first instant, the movement, with a first excursion, of the driving member 7 along the axis X, in the direction away from the abutment surface 12, determines a corresponding displacement of the second shutter 6 along the axis X , allowing a flow of fluid through the communication channel 5b and the compensation chamber 5a. According to some embodiments, the first shutter 5 comprises a communication surface 55 comprised in said compensation chamber 5a near the communication channel 5b and a surface distal 56 with respect to the communication channel 5b, substantially opposite to the communication surface 55.

[0095] Preferably, the area of the communication surface 55 is greater than the area of the distal surface 56; therefore, when the second shutter 6 is moved along the axis X with a first excursion of the actuator 7, opening the communication channel 5b, the shutter end 5d remains in contact with the abutment surface 12 since the force exerted on the communication surface 55 is greater than the force exerted on the distal surface 56.

[0096] Advantageously, the possibility of creating the balance of the forces as described above allows not to interpose further mechanical elements between the first shutter 5 and the second shutter 6, such as, for example, elastic elements, e.g. springs, aimed at maintaining the first shutter 5 in the closed position, while the second shutter 6 is moved to open the communication channel 5b, with the first excursion, so as to compensate for the pressure difference between the inlet la and the outlet lb.

[0097] Thanks to this compensation, the force exerted by the actuator 7 through the second shutter 6 on the first shutter 5, with the second excursion, does not cause the deformation or breakage of the latter, given the lower forces in play in an opening phase of the outflow channel 3.

[0098] According to some embodiments in which the passages 5f, preferably in the form of a slot, extend up to the base 5h of the first shutter 5, the force exerted on the communication surface 55 is added to the force exerted on the base 5h, in this way the second shutter 6, with the first excursion, can freely slide along the axis X without the first shutter 5 moving from the closed position. In this way, no further mechanical elements are necessary between the first shutter 5 and the second shutter 6, such as for example elastic elements, e.g. springs, aimed at maintaining the first shutter 5 in the closed position, while the second shutter 6 is moved to open the communication channel 5b.

[0099] As illustrated above, the first shutter 5 is movable along the axis X with a second excursion of the actuator 7, pulled by the second shutter 6, so as to achieve a flow of the fluid exiting from said valve 1.

[0100] Summarizing, in an opening phase, the driving member 7 and the second shutter move along said axis X away from the communication channel 5b and in general from the second zone 3b. By moving away from this zone 3b, the driving member 7 moves the second shutter 6 opening the communication channel 5b. The second shutter 6, by moving away from the abutment surface 12, travels a first section disengaged from the first shutter 5 and a second section moving, by pulling, also the first shutter 5 away from the abutment surface 12.

[0101] In order to transmit the movement of the driving member 7 to the second shutter 6, the latter may comprise a connection end 6d connectable with the driving member 7.

[0102] In some embodiments, the driving member 7 comprises a thread and said valve body 2 comprises a counter-thread such that a rotational movement of the driving member 7 is converted into a translational motion along the axis X. The connection end 6d is rotatably connected with the driving member 7 such that the rod 6a is disengaged from the rotational motion of the driving member 7 itself.

[0103] Preferably, the connection end 6d has a substantially cylindrical shape with a diameter greater than said rod 6a and, the rod 6a preferably comprises a shoulder 6e which is integral therewith, which preferably extends in an annular manner around said rod 6a.

[0104] With reference to figures 3 and 4, it can be observed that in preferred embodiments the valve seat 4 comprises three sections: a first actuation section 4a of cylindrical shape in which the driving member 7 is movable, a second sliding section 4b of cylindrical shape with a diameter that is smaller than the actuation section 4a, in which said first 5 and second 6 shutter are slidably housed, a flow section 4c also of cylindrical shape with a diameter greater than said sliding section 4a of which said first shutter 5 determines the opening or closing.

[0105] In fact, the flow section 4c faces the outlet lb and is fluid-dynamically connected thereto when the valve 1 is open.

[0106] When the valve 1 is closed, the first shutter 5 stops on the abutment surface 12 which is defined at said flow section 4c. In particular, when the valve 1 is closed, the first shutter 5 is in contact with a perimeter region of the second outlet portion lib at the flow section 4c.

[0107] The flow section 4c fluid-dynamically communicates with the inlet channel 111b.

[0108] Preferably, the main body 5e of the first shutter 5 is positioned mainly at the flow section 4c.

[0109] Preferably, the base 5h of the first shutter is positioned in the sliding section 4b. Preferably, the valve 1 comprises a sealing element 8.

[0110] Preferably, the sealing element 8 is connected to the driving member 7 such that the driving member 7 is sealingly housed in the first actuation section 4a.

[0111] According to some embodiments, the sealing element 8 is strikingly connected with the driving member 7 and is free to slide along the axis X around the driving member 7.

[0112] In preferred embodiments, between the shoulder 6e and the driving member 7, the valve 1 comprises a sealing element 8.

[0113] The sealing element 8 is positioned between said shoulder 6e and said second shutter 6. Preferably, a sealing volume 88 is defined between the sealing element 8 and the base 5h of the first shutter 5.

[0114] Preferably, said sealing element 8 is movable along said actuation axis X, between said shoulder 6e and said second shutter 6. In preferred embodiments, the sealing element 8 comprises an abutment member 8a, arranged near the shoulder 6e and a pair of lips 8b which extend in a divergent manner from the abutment member 8a, thereby a pressurized fluid in said valve seat 4 tends to urge them away.

[0115] In some embodiments there is further a reinforcement element 8c which is arranged between said lips 8b. Advantageously, the abutment member 8a and the lips 8b can be made from plastics material while the reinforcement element 8c is made from metal material.

[0116] Advantageously, when the valve 1 is closed, the presence of the sealing element 8, in particular of the sealing element 8 comprising the abutment member 8a and a pair of lips 8b, allows to keep the flow channel 4c, the compensation chamber 5a and the sealing volume 88 at the same pressure.

[0117] Indeed, it will be appreciated that, preferably, there are no by-passes between the outlet lb and the sealing volume 88, since the presence of the sealing element 8 substantially allows to eliminate the losses that could occur from the sealing volume 88, despite being subjected to high pressures, for example between 100 bar and 300 bar, preferably 300 bar.

[0118] According to some embodiments comprising the sealing element 8, in particular the sealing element 8 comprising the abutment member 8a and a pair of lips 8b, the pressure of the fluid at the inlet acts on the base 5h, on the communication surface 55 and on the distal surface 56 allowing the formation of a static balance between the forces such as not to require the presence of further mechanical elements between the first shutter 5 and the second shutter 6, such as for example elastic elements, e.g. springs. In this way the first shutter 5 remains in the closed position, while the second shutter 6 is moved, with the first excursion, to open the communication channel 5b.

[0119] The driving member 7 comprises a housing end 7a that abuts a wall of the valve seat 4 and comprises a connection opening 7b which is shaped thereby allowing the insertion of the connection end 6d while mounting said valve 1.

[0120] The shoulder 6e preferably has a diameter that abuts said wall of said valve seat 4 so as to remain in the housing end 7a once the rod 6a and the actuator 7 are inserted in the valve seat 4.

[0121] In order to be able to actuate the valve, the driving member 7 comprises an actuation portion 7c, illustrated in figure 5, couplable with a transmission member with a force that is suitable for passing the valve 1 from the open position to the closed position and vice versa.

[0122] The actuation portion 7c is preferably realized as a polygonal cavity obtained in the driving member 7 at an actuation end 7d distal to said connection end 6d.

[0123] At the polygonal cavity, the driving member 7 can have a reduction in diameter that creates a gap 77, visible in figure 6, between a wall of the actuation section 4a and a wall thereof, to allow an auxiliary guide 9 to be housed, preferably in self-lubricating material.

[0124] To seal the valve seat 4, the valve 1 may comprise a further sealing element 10 (figure 6) which connects the actuation end 7d with an edge of said valve body 2 and extends into the gap 77 between the auxiliary guide 9 and a wall of the valve body 2.

[0125] Obviously, a person skilled in the art may, in order to meet specific and contingent application requirements, make further modifications and variants, all falling within the scope of protection as defined by the following claims.

Claims

CLAIMS1. Valve (1) for pressurized fluids comprising a valve body (2) including an inlet (la), an outlet (lb) and an outflow pipe (3) putting said inlet (la) in hydraulic communication with said outlet (lb), said valve (1) further comprising:- a valve seat (4) arranged along said outflow pipe (3);- a first shutter (5) and a second shutter (6) which are configured thereby opening and closing said valve seat (4) by moving away and towards respectively, along an actuation axis (X), an abutment surface (12) defined in said valve seat (4); and- an driving member (7) connected to said second shutter (6) and configured to actuate said first shutter (5) and said second shutter (6) thereby opening and closing said valve seat (4); wherein said first shutter (5) defines a compensation chamber (5a) therein a portion of said second shutter (6) is received, thereby supporting said first shutter (5) with sliding capacity along said actuation axis (X), wherein said first shutter (5) comprises at least one passage (5f) configured to put said compensation chamber (5a) in hydraulic communication with said inlet (la) and further includes a communication channel (5b) connecting said compensation chamber (5a) with said outlet (la), wherein said communication channel (5b) defines a passage section with extension that is smaller than a corresponding passage section of said outflow pipe (3) in the region of said valve seat (4), said driving member (7) being configured to move said second shutter (6) in the opening direction, releasing said communication channel (5b) and, once said communication channel (5b) is open, pulling said first shutter (5) in the opening direction, away from said abutment surface (12).

2. Valve (1) according to the preceding claim, wherein said first shutter (5) comprises a main body (5e), which is preferably substantially cylindrical and therein said compensation chamber (5a) is defined, and a shutter end (5d) which tapers towards a vertex defined at said actuation axis (X).

3. Valve (1) according to claim 2, wherein said communication channel (5b) is positioned at said vertex.

4. Valve (1) according to any one of the preceding claims, wherein said second shutter (6) comprises a connection end (6d) which is rotatably connected to said driving member (7).

5. Valve (1) according to any one of the preceding claims, wherein said drivingmember (7) is connected to said valve body (2) by means of a thread so as to convert a rotational motion of said driving member (7) into a translational motion along said actuation axis (X), said connection end (6d) being configured to disengage said second shutter (6) from the rotational motion of said driving member (7) during said translational motion along said actuation axis (X).

6. Valve (1) according to any one of the preceding claims, wherein said second shutter (6) comprises a rod (6a) and a head (6b).

7. Valve according to claim 6, wherein said head (6b) includes a closure element (6c) which is configured to close said communication channel (5b).

8. Valve (1) according to claim 6 or 7, when dependent on claim 4, wherein said rod (6a) and said connection end (6d) have a substantially cylindrical shape, said connection end (6d) having a diameter greater than said rod (6a).

9. Valve according to any one of claims 6 to 8, wherein said rod (6a) comprises a shoulder (6e) which is integral therewith and which extends in an annular manner around said rod (6a).

10. Valve (1) according to any one of the preceding claims, comprising a sealing element (8).

11. Valve (1) according to claim 10, wherein said valve seat (4) comprises a first actuation section (4a) wherein said driving member (7) is movable, said sealing element (8) being connected to said driving member (7) so that said driving member (7) is sealingly housed in said first actuation section (4a).

12. Valve (1) according to claim 10 or 11, wherein said sealing element (8) is arranged between said actuator (7) and said first shutter (5).

13. Valve (1) according to claim 9 and any one of claims 10 to 12, wherein said sealing element (8) is arranged between said shoulder (6e) and said first shutter (5).

14. Valve (1) according to any one of claims 10 to 13, wherein said sealing element (8) comprises an abutment member (8a), and a pair of lips (8b) extending in a divergent manner from said abutment member (8a), thereby a pressurized fluid in said valve seat (4) tends to urge said lips (8b) away from each other.

15. Valve (1) according to claim 12 when dependent on claim 11, wherein said abutment member (8a) is arranged near said shoulder (6e).

16. Valve (1) according to claim 14, wherein said sealing element (8) comprises a reinforcement element (8c) which is arranged between said lips(8b).

17. Valve (1) according to claim 16, wherein said abutment member (8a) and said lips (8b) are made from plastics material and said reinforcement element (8c) is made from metal material.

18. Valve (1) according to any one of the preceding claims, when dependent on claim 6, wherein said first shutter (5) is elastically deformable for the said first shutter (5) to fit in said second shutter (6) by insertion of said head (6b) in said compensation chamber (5a).

19. Valve (1) according to any one of the preceding claims, wherein said first shutter (5) is made from plastics material.

20. Valve (1) according to any one of the preceding claims, wherein said valve (1) is configured to be used at pressures comprised between 0 bar and 400 bar.

21. Valve (1) according to any one of the preceding claims, wherein said at least one passage (5f) is in the form of a slot which extends substantially parallel to said actuation axis (X).

22. Valve (1) according to any one of the preceding claims, wherein said first shutter (5) comprises a base (5h), said at least one passage (5f) extending from said compensation chamber (5a) to said base (5h).

23. Valve (1) according to any one of the preceding claims, wherein said first shutter comprises an outer side surface (57) of the main body (5e).

24. Valve (1) according to claims 22 and 23, wherein said at least one passage (5f) extends from said compensation chamber (5a), up to said base (5h) and up to said outer side surface (57).

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