DESCRIPTION

Technical field of the invention

The present invention relates to a multi

selector valve for use in "Oil and Gas" field, which collects the flows coming from the well

lines and enables the analysis of the parameters of each single supply line, by selectively deflecting each flow to be analyzed. The flow isolation is obtained by means of an innovative selector and sealing organ .

Background art

As known, in the production of oil, natural gas and other fluids, valves are necessary in any operation because of the need to direct the flow of fluids (gas, water and oil) between wells, pumps, tanks and refineries. In general, the development of oil and gas comprises drilling, production (supply of surface fluids), treatment of various oil and gas mixtures and transportation to oil refineries and gas outlets. Generally, the fluids coming from the wells are transported in a in central collection point, in order to further combine or separate them for subsequent processes such as refining, gas sale, etc. In addition, tests are often required for each flow to ensure the quality of the fluids produced. As a result, the production of each well is generally directed to a collection point which directs the products of the well to various test and/or production destination. In order to do so, in general pipes or system of pipes and multi selector valves are used in order to direct the flows to the desired positions and to drive more inlets to a single destination.

Such technique is known and can be derived for example from document US2012216887 Al, in which a multi-selector valve is described comprising a flow fitting pivotally arranged in order that the flow can be aligned by rotation with each of the plurality of inlet openings. Another example of known multi-selector valves applied in the "Oil and Gas" field is described in document CN105179749. Finally, document US2017/0219105A1 describes a multi-selector valve applied to internal combustion engines, therefore outside the scope of interest of the present invention.

In the known solutions, moreover, the fittings of the multi-selector valves are based on the technology that puts cylindrical surfaces in contact with each other, i.e. a first convex cylindrical surface (SEAT) is pre- loaded against a second concave cylindrical surface (BODY) between the selector element and each supply line. Generally the multi-selector valves are provided with a single soft convex cylindrical surface (SEAT) which is pre-loaded against the same internal surface of the concave body (BODY) of the different lines and in order to perform the coupling and sealing.

The known solutions have the drawbacks due to sealing losses between the selector element and one or more lines, as a result of the wear of the soft connecting surfaces that very often cause leaks also from other lines. This results in having to carry out plant stops or, generally every six months, to monitor the different supply lines.

Furthermore, the known art does not ensure a simultaneous and reliable sealing of all the supply lines, so as to allow the full operation of the system when the valve selectively prepares the deviation of the flow to be analyzed .

There is, therefore, the need to define an innovative selector and sealing organ for a multi-selector valve that is free from the drawbacks mentioned above.

Summary of the invention

The present invention has the aim of solving the following technical problems by: improving the isolation of the supply line to be characterized and the sealing of the selector element by making it more reliable and long-lasting, in order to guarantee the full operation of the system when the valve presets a selective diversion of flow to be analyzed and by therefore increasing the performances of the multi-selector valve with respect to that referred to in the known art.

For such aim, according to the invention, the multi-selector valve has an innovative selector and sealing organ, i.e. a coupling between a conical surface (SEAT) and a spherical surface (BALL) between the selector element and each supply line, which has the characteristics set out in the independent product claim.

Further preferred and/or particularly advantageous embodiments of the invention are described according to the characteristics set out in the appended dependent claims.

Brief description of the drawings

The invention will now be described with reference to the attached drawings, which illustrate some non-limiting examples of embodiments, in which:

- Figure 1 is an axonometric view of a set of multi-selector valve,

- Figure 2 is a schematic section of the inside of a multi-selector valve comprising a selector and a sealing element according to the present invention, wherein the selector element is in the rest position,

Figure 3 is a schematic view of a longitudinal section of the multi-selector valve of Fig. 2,

- Figure 4 is a schematic section of the inside of a multi-selector valve comprising a selector and sealing element according to the present invention, wherein the selector element is in the interception and deviation position of the line to be calibrated,

Figure 5 schematically shows a longitudinal section of the multi-selector valve of Fig. 4,

- Figure 6 is a cross section of the multi selector valve of Fig. 1, in which the shape of the shutter and the sealing element is shown according to the present invention,

Figure 7 is a detail of the sealing between the selector element and the supply line, according to the present invention,

Figure 8 is a detail of the multi selector valve of Fig. 1, wherein elastic means are visible, which ensure the sealing between the selector element and the supply line, according to the present invention,

- Figure 9 shows the multi-selector valve in which the elastic means of Fig. 8 are adapted to simultaneously ensure the sealing between selector elements and the supply lines, and Figure 10 is a detail of the sealing between the valve body, the selector element and a supply line.

Detailed description

With reference to the aforesaid figures, Figure 1 is an axonometric overall view of a multi-selector valve 100. The multi-selector valve 100 comprises a valve body 4, a plurality of inlet fittings 1 in connection with the respective supply lines la, for example seven in number (shown in Figures 2-5), coming from a plurality of wells positioned between them at various distances, a delivery connector 20 and a delivery connector for carrying out tests 2'.

In the resting position, shown in Figure 2 and Figure 3, the selector element 10 isolates the discharge for the execution of tests 2', as the same is not in communication with any inlet fitting 1, but communicates with the so-called resting (inactive) position 2.

With reference to Figure 4 and Figure 5, the selector element 10 is shown during the working phase. In particular, for example, the selector element 10 isolates a fitting or inlet

1' of the plurality of inlet fittings 1, in connection with an operating supply line la', to carry out the test, putting it in communication with the delivery connector for the execution of tests 2'. Once the analysis has been completed, the selector element 10 is handled to test another supply line or to return to the resting position 2. With reference to Figure 6, the selector element 10 is visible in cross section and in particular a first connection 10' between an inlet fitting 1 of the intercepted supply line and the delivery connector for the execution of test 2'. A second connection 10" is also visible, with a generic supply line which has not been tested.

Advantageously, the geometry of the connections 10" is identical for all supply lines la.

More particularly, with reference to Figure 6 and 7, in a transverse cross-section the sealing area is shown between the selector element 10 and a generic inlet fitting 1.

The pressure sealing between the selector element 10 and an inlet connector 1 is realized through a sealing element or seat 11 which, being formed with a conical surface 3 coupled to a spherical surface 12 of the selector element 10, generates a conical-spherical coupling. This sealing is present on each of the eight inlet fittings 1 of the multi- selector valve 100.

Both the selector element 10 and the sealing seat 11 are coated on the surface by means of the addition of either metal carbides (tungsten or chromium) or with a surface hardening treatment (nitriding) , which allows to generate the conical-spherical pressure sealing between fully metal elements (conical surface 3 of the sealing seat 11 and the spherical surface 12 of the selector element 10), by limiting wear and preventing seizing of the parts.

In particular, the conical surface 3 of the sealing seat 11 and the spherical surface 12 of the selector element 10 are surface hardened, for example by means of a tungsten carbide/chromium coating (HVOF) up to a thickness ranging between 150 and 400 pm and by reaching a hardness equal to or greater than

1000 HV. The stable contact between the conical surface 3 and the spherical surface 12 is ensured by a plurality of elastic means 5, also visible in Figure 8, which are preloaded between a surface of the inlet fitting 1 and a seat surface sealing 11, located on a band opposite to the conical surface 3 of the sealing seat 11. In this way the elastic means 5 ensure, in any operating situation, a sure and reliable contact of the conical surface 3 of the sealing seat 11 and the spherical surface 12 of the selector element 10.

It is to be observed, as shown in Figure 9, that the plurality of elastic means 5 is present on each inlet fitting 1 with the same preloading mode. In this way, it is possible to ensure a simultaneous and reliable sealing of all supply lines la, so as to allow the full operation of the system when the valve selectively prepares the deviation of the flow to be analyzed.

Furthermore, returning to Figure 7, an elastomeric or thermoplastic gasket 6 is interposed between the inlet fitting 1 and the sealing seat 11, so that the gasket sail ensures the sealing between the two components.

Advantageously, the conical-spherical sealing allows to create a complete spherical contact surface between the shutter and the seat and therefore it does not allow any leakage .

Advantageously, the sealing performances are the same as for the traditional ball valves, and it is therefore possible to achieve ISO 5208-Rate A.

Even more advantageously, the metal-metal sealing is obtained, in order to ensure long lasting performances with low maintenance. Both the conical surface and the spherical surface shutter are made of metal, and are coated by means of a thermal spray coating method called High-Velocity Oxy-Fuel (HVOF) > 1000HV. The typical coatings of the sealing surfaces, for example, can be 316L SS, 22Cr Duplex SS, 25Cr Super-Duplex SS, Inconel® 625 (E-NiCrMo3 or ER-NiCrMo3 ) .

As shown in more detail in Figure 10, the sealing between the valve body 4 and an inlet fitting 1 comprises a first seal 7 and a second seal 8. The first seal 7 can be an elastomeric or thermoplastic sealing, depending on the operative conditions. The second seal 8 is an elastomeric gasket for containing the pressure in the event of damage to the first gasket 7, due for example to an exposure to fire. Advantageously, this combination of seals fully complies with the requirements of the fire specifications and it is then certified. This type of "redundant" sealing is applied to all joints between valve body 4 and inlet fittings 1.

In addition to the embodiments of the invention, as described above, it is to be understood that there are numerous further variants. It must also be understood that said embodiments are only examples and do not limit neither the object of the invention, nor its applications, nor its possible configurations. On the contrary, although the above description makes it possible for the skilled man to implement the present invention, at least according to an exemplary configuration, it must be understood that numerous variants of the described components are conceivable, without thereby abandoning the object of the invention, as defined in the attached claims, literally interpreted and/or according to their legal equivalents.