First reducing stage with low thermal conduction elements

Abstract

A first reducing stage for two-stage regulator assemblies includes a first chamber for a high-pressure breathable gas; a second chamber for the breathable gas at an intermediate pressure; a pressure reducing valve connecting the two chambers and having a valve seat with an opening for communication between the two chambers; and a plug cooperating with the valve seat and dynamically connected to a sensor exposed to water to the outer water pressure. The sensor is at least partly accommodated in a housing chamber defined by one or more elements cooperating to provide support and partial movement constraint to the sensor, and forming the housing chamber and/or at least part of the sensor. The one or more elements are made of a material or a combination of materials having thermal conductivity lower than a metal material, and mechanical properties that do not affect correct operation compared to metal materials.

Claims

1. A first reducing stage for two-stage regulator assemblies, comprising: a first chamber for a high-pressure breathable gas, the first chamber being adapted to be connected through an inlet to a high-pressure gas source; a second chamber for the breathable gas at an intermediate pressure, the second chamber having an outlet for the breathable gas at the intermediate-pressure and being adapted to be connected to a user of the breathable gas; and a pressure reducing valve connecting to each other the first chamber and the second chamber, the pressure reducing valve comprising a valve seat with an opening for communication between the first chamber and the second chamber, and a plug cooperating with the valve seat and movable from a position closing the opening to a position opening the opening, and vice versa, wherein the plug is dynamically connected to a sensor exposed to water and to a pressure of an environment outside the first chamber and the second chamber, the sensor comprising a mechanism transmitting a mechanical stress exerted on the sensor by the pressure of the environment outside the plug, wherein the sensor is at least partly accommodated in a housing chamber defined by one or more elements cooperating with each other to provide support and partial movement constraint to the sensor, and wherein the one or more elements forming the housing chamber and/or at least part of the sensor are made of a material or a combination of materials having thermal conductivity lower than the thermal conductivity of metal materials, the material or the combination of materials having mechanical properties such that use of the material or the combination of materials in place of the metal materials does not affect a correct operation of the first reducing stage.

2. The first reducing stage according to claim 1, wherein at least one of the one or more elements forming the housing chamber and/or the sensor are at least partially made of a non-metal substance.

3. The first reducing stage according to claim 2, wherein the non-metal substance is a plastic material selected from the group consisting of: Polyoxymethylene (POM) Acetal Resins, Synthetic polyamides (PA), Polyphenylene sulphide (PPS), Polybutylene terephthalate (PBT), Polyketone (PK), Liquid crystal polymer (LCP), Polyether ether ketone (PEEK), or a combination thereof.

4. The first reducing stage according to claim 2, wherein the non-metal substance is a plastic material comprising a fiber-reinforced polymer compound.

5. The first reducing stage according to claim 4, wherein the fiber-reinforced compound comprise reinforcing fibers in a volumetric percentage of up to 50% of total.

6. The first reducing stage according to claim 4, wherein the fiber-reinforced compounds comprises glass-based fibers, carbon fibers, or a combination thereof.

7. The first reducing stage according to claim 2, wherein the non-metal substance is a technopolymer.

8. The first reducing stage according to claim 1, wherein the sensor comprises a diaphragm with a preload adjusting mechanism.

9. The first stage according to claim 8, wherein the first reducing stage comprises one or more of the following elements: a sliding body and/or a membrane-locking body; or an adjustable stationary element for preload adjustment of the plug.

10. The first reducing stage according to claim 1, wherein the sensor and the housing chamber are of a cylinder/plunger type, wherein the sensor comprises two movable wall elements rigidly connected to each other, and spaced apart from each other due to mutual connecting members in parallel to a moving direction, one of the movable wall elements providing an interface with the external environment and another one of the movable wall elements providing an interface between the housing chamber of the two movable wall elements toward the second chamber, wherein the movable wall elements sealingly delimit, respectively towards the external environment and towards the second chamber, an interposition chamber which is insulated from the external environment and from the second chamber, the interposition chamber being a segment of the housing chamber with variable position and having an extension in a sliding direction of the two movable wall elements that corresponds essentially to a distance of the two movable wall elements from each other, wherein each of the movable wall elements is configured as a plunger housed in the housing chamber that operates as a cylinder, both plungers being sealingly guided along walls of the cylinders due to peripheral sealing gaskets, wherein both of the movable wall elements is arranged to move inside a respective cylinder in parallel orientation and in a direction of a cylinder axis, the cylinder axis being at least parallel or coaxial to a direction of movement of the plug between the two positions of opening and closing the opening of the valve seat, transmission members being a rod connecting the sensor to the plug, wherein an axis of the opening of the valve seat is coincident or parallel to the cylinder axis of the cylinder forming the housing chamber of the sensor, the plug being a sealing element mounted on a piston sliding in a cylindrical seat, the piston and the cylindrical seat being parallel or coincident with the axis of the opening of the valve seat and/or with the cylinder axis, wherein the first chamber, the second chamber, the housing chamber, the valve seat and/or the opening in the seat, the plug and a guide seat thereof, the two movable walls of the sensor, the rod connecting between the sensor and plug all have a rotational symmetry and are coaxial to each other, wherein the plug is combined with an elastic preload element adjustable via a preload adjusting member, wherein a preload adjusting member is combined with the sensor, the preload adjusting member being positioned inside the interposition chamber delimited by the two movable wall elements, wherein, between the two movable wall elements, a flexible membrane is placed and sealingly mounted by a threaded ring nut at an end of the housing chamber of the two movable wall elements, and wherein at least one or some or all of: the one or more bodies forming the housing chamber; the threaded ring nut for sealing the flexible membrane; the adjusting member of the elastic preload element; or the plunger interfacing with the external environment, are made of a material or a combination of materials having thermal conductivity lower than a thermal conductivity of a metal material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Additional advantages and features of a device according to the present invention will become evident from the following detailed description of embodiments of the same and, in particular, with reference to two common variants of pressure reduction apparatuses, in which:

[0051] FIG. 1 illustrates a diaphragm type and the double piston subtype according to the invention in sectional views; and

[0052] FIG. 2 illustrates a diaphragm type and the double piston subtype according to the invention in sectional views.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0053] The figures show one of the numerous possible embodiments, by way of non-limiting examples. The benefits of the present invention are also available not only from the two types of reducer presented herein but also from the many devices which include gas expansion chambers and moving elements subject to operating interference due to excessive cooling of the environment in which they operate.

[0054] FIG. 1 shows a diaphragm-type first stage according to the known art. In this type of first-stage reducing device of a two-stage dispensing assembly, a membrane 2402 is provided which seals an intermediate pressure chamber 2201 towards the outside environment, which membrane is held in position by the membrane locking nut 2107. The membrane 2402 cooperates on the side exposed to the external environment with a preload spring 2432, which is interposed between an adjustable stationary abutment, for example a threaded preload ring 2452, and a plate 2422 for supporting the membrane 2402 itself. On the side of the membrane 2402 facing the intermediate pressure chamber 2201, the membrane 2402 cooperates with a further plate 2331 which is connected to the shutter 2311 of the reduction valve between the intermediate pressure chamber 2201 and the high-pressure chamber 2101, which is fed from one or more inlets (not visible in the figure) for high-pressure gas. The plate 2331 is connected to the shutter 2311 by means of a rod 2321 which transmits to the shutter the force generated by the external pressure and by the spring 2432 on the membrane 2402. A further elastic element of preload 2451 acts on the shutter 2311.

[0055] In this embodiment, the membrane 2402 therefore has both the function of transmitting the pressure of the external environment to the shutter of the pressure reducing valve and the function of sealingly separate the intermediate pressure chamber from the external environment, that is, the fluids present in the intermediate pressure chamber from the outside fluid. The membrane 2402 is secured tightly between two annular clamping stops, one on the main body of the first stage and the other on the membrane locking nut, which cooperate with a peripheral annular band of the membrane itself.

[0056] Considering the multiplicity of elements that make up a diaphragm-type first pressure reducing stage in the form as described, which is only one of the possible implementations, an embodiment of the invention provides that at least one or some of the elements described are made with one or a combination of plastic materials having a high thermal insulation, i.e., low heat conduction.

[0057] A preferred embodiment comprises, among the elements with low thermal transmission, one or more of the following elements:

[0058] membrane locking nut 2107;

[0059] preload adjustment ring nut 2452 of the shutter 2311.

[0060] In this embodiment, at least one or some or all of said elements are made according to one or more of the innovative features of the invention.

[0061] In particular, it is the membrane locking nut which, if made of metal, transmits the cold generated in the main body of the first stage to the water above the membrane and around the spring. By replacing this element with one having low thermal conductivity, the water above the membrane and around the spring is affected in a much lesser way by the cooling so the regular operating time increases significantly.

[0062] FIG. 2 shows a double piston first stage reducer (subcase of the diaphragm-type first stage). The presence of two pistons can be found in the same FIG. 2, where there is a first piston 1104 exposed to the external environment with sealing to the environment and a second piston 1402 which cooperates with said first piston 1104, moving in common with it inside the housing chamber 1102.

[0063] A high-pressure chamber is made in the main body 1, the chamber having one or a plurality of inlets to connect a high-pressure breathing gas source, not shown in the figure and per se known as a high-pressure breathing gas supply cylinder. The seat 1301 of the reduction valve is located in the chamber 1101, which seat opens into the intermediate pressure chamber 1201, and the flow therethrough is regulated by the shutter 1311. The shutter 1311 is connected to a stem 1321, which ends at the opposite end with a plate 1331, inside the chamber 1201. The intermediate pressure chamber 1201 is provided with a plurality of outlets not shown in the figure.

[0064] At the top of the intermediate pressure chamber 1201, there is formed a threaded opening 1401 in the body 1 of the first stage, in which opening the block 1106 is screwed, sealed thanks to the gasket 1411. Inside the block 2 there is formed a cylindrical chamber 1102 for housing movable wall elements 1402, 1104. According to the preferred but not exclusive embodiment of FIG. 2, said movable wall elements 1402 and 1104 have a rotational symmetry and are in the form of a circular piston which is movable in the direction of its axis within a rectified section inside the cylindrical chamber 1102.

[0065] The movable wall elements 1402 and 1104 slide tightly thanks to peripheral annular seals 1422 and 1462 (the latter optional), along the rectified cylindrical wall. The stroke is limited at least on one side by an end-of-stroke stop in the form of a threaded ring 1105 which acts as a containment for one (in the absence of 1462 on 1104 the diaphragm is not optional) flexible diaphragm 1212, which is alternatively present to said annular gasket 1462, which flexible membrane, when present, adheres to the face of the mobile wall element 1104 facing towards the external environment and interfacing with it.

[0066] The opposite end of the stroke is limited by the abutment position of the shutter against a stop in the high-pressure chamber. The two end-of-stroke positions are axially spaced from each other, i.e., spaced one from the other in the direction of movement of the movable wall element 1402. The gasket 1422 is inserted in a toroidal groove provided in the skirt edge of the movable wall element. 1402.

[0067] An annular groove 1442 is formed on one face of the movable wall element 1402; this groove has the purpose of cooperating with a helical preload spring 1432. A preload ring 1452 which is screwed to the block 1106, inside the chamber 1102 at a certain axial distance from the movable wall element 1402, constitutes the stationary abutment against which the end of the helical spring 1432 abuts which is opposite to the one resting on the movable wall element 1402.

[0068] The rod 1321 which rigidly connects the movable wall element 1402 to the shutter 1311 passes through coaxial holes of the shutter 1311 itself, which forms the end of stoke stop of the piston in the cylindrical chamber 1102 in which said piston 1402 is housed. Advantageously, the rod 1321 is not mechanically connected to the movable wall element, but rests against it, optionally and preferably thanks to an end plate 1331.

[0069] Considering the multiplicity of elements that forms a first pressure reducing stage in the form as described, which is only one of the possible implementations, an embodiment of the invention provides that at least one or some of the elements described are made with one or a combination of plastic materials providing high thermal insulation, i.e., low heat conduction.

[0070] A preferred embodiment comprises, among the elements with low thermal transmission, one or more of the following elements:

[0071] sliding body 1106;

[0072] closing member 1105;

[0073] preload adjustment organ 1452 of the shutter 1311;

[0074] movable piston elements or pistons 1104 and/or 1402.

[0075] In this embodiment, at least one or some or all of said elements are made according to one or more of the innovative features of the invention. In particular, if both pistons are made of metal, the cold is transmitted to the membrane 1212, on which ice can form. The cold can also be transmitted from the main body 1 to the sliding body 1106 and from there to the ring 1105, resulting in the formation of ice all around. At the moment, when the membrane 1212 is covered by an important layer of ice, it would no longer be able to effectively transmit the ambient pressure to the upper piston. By replacing one or more of these components with equivalents made of low thermal conductivity material, the already considerable resistance to cold of this system is further increased.