VALVE FOR METHANE IN AUTOMOTIVE SYSTEMS WITH IMPROVED SEALING

1 . Valve for flow control of methane in automotive systems during supply at high speed and low temperatures, the valve comprising at least one sealing group comprising a proximal sealing seat and a distal sealing seat adjacent to the proximal sealing seat, a proximal sealing ring, in direct contact with gas in rest conditions and housed in the proximal sealing seat, and a distal sealing ring housed in the distal sealing seat, wherein the proximal sealing ring and the distal sealing ring are made of different materials and the material of the distal sealing ring has at the low temperatures an elasticity greater than the material of the proximal sealing ring.

2 . Valve according to claim 1 , wherein the material of the distal sealing ring exhibits from −30° C. to −50° C. a greater elasticity than the material of the proximal sealing ring.

3 . Valve according to claim 1 , wherein the distal sealing ring is made of an FKM fluorocarbon rubber.

4 . Valve according to claim 1 , wherein the distal sealing ring is made of an FMQ or FVMQ fluorosilicone rubber.

5 . Valve according to claim 1 , wherein the sealing group comprises at least one anti-extrusion ring housed in a sealing seat to keep the relative sealing ring in sealing seat.

6 . Valve according to claim 5 , wherein the anti-extrusion ring is housed in the distal sealing seat to keep the relative distal sealing ring in the distal sealing seat.

7 . Valve according to claim 1 , comprising a check valve device applied to an entrance duct, wherein said device comprises said sealing group.

8 . Valve according to claim 1 , comprising a tap manually operable to intercept flow of gas towards a delivery duct, wherein said tap comprises a shaft and a bush crossed by said shaft, applied to the valve body.

9 . Valve according to claim 8 , wherein the shaft comprises said sealing group to form a seal with the bush.

10 . Valve according to claim 8 , wherein the bush comprises said sealing group to form the seal with the valve body.

11 . Valve according to claim 1 , comprising a temperature-sensitive thermal safety device comprising an obturator adapted to intercept flow of gas towards a discharge duct, wherein said obturator comprises said sealing group.

12 . Valve according to claim 11 , wherein the thermal safety device comprises a driver device adapted to obtain a pressure difference between a zone upstream and a zone downstream of the obturator, wherein said driver device comprises a driving obturator provided with said sealing group.

13 . Valve according to claim 1 , comprising a plug for closure of a rear compartment towards outside, wherein said plug is provided with said sealing group.

14 . Valve according to claim 1 , comprising an electrovalve to allow or prevent flow of methane towards the delivery duct, comprising an engagement body applied to the valve body and an obturator member, wherein said engagement body comprises said sealing group to form a seal with the valve body.

15 . Check valve device applicable to a valve body of a valve for flow control of methane in automotive systems, said device being adapted to intercept flow of gas between an entrance duct and a reservoir duct of said valve, comprising an entrance sealing group comprising a proximal sealing seat and a distal sealing seat adjacent to the proximal sealing seat, a proximal sealing ring housed in the proximal sealing seat, and a distal sealing ring housed in the distal sealing seat, wherein the proximal sealing ring and the distal sealing ring are made of different materials.