Automatically-actuated safety device with a double-seated valve to regulate the flow rate of a fluid
A safety device for insertion into a pipeline (K) in which fluid circulates in an upstream (X−) and a downstream (X+) direction, comprises a tube ( 1 ) that provides the fluid with a central circulatory passage (CC) regulated by a central valve ( 3 ) that closes in the event of an excessive flow of this fluid. There is an annular valve closure member ( 4 ) which is elastically malleable, mounted to the external periphery of the tube ( 1 ), and provides the fluid with a peripheral circulatory passage which it selectively obstructs by subjecting a radial expansion in the event of an excessive flow of fluid.
1. Safety device inserted into a fluid pipeline (K) having a set minimal sectional area, said device protecting said pipeline against excessive flow rates of fluid circulating in said pipeline from upstream (X−) to downstream (X+), said device comprising:
(a) a tube ( 1 ) with open upstream and downstream ends ( 10 , 11 ) and providing a central circulatory passage (CC) for the fluid;
(b) a retention device ( 2 ) to hold the tube ( 1 ) in place within the pipeline (K), and
(c) a fluid circulation regulator comprising:
(1) a central valve having:
(i) a valve seat ( 30 ) embedded in the tube ( 1 );
(ii) a central valve closure member ( 31 ) selectively applied to the valve seat ( 30 ); and
(iii) a spring ( 32 ) exerting on the central valve closure member ( 31 ) an elastic opening force which opens the central valve closure member a distance from the valve seat ( 30 ), counter to a closure force exerted on the central valve closure member ( 31 ) by loss of head which increases with a flow rate of fluid in the pipeline (K),
(2) an annular valve closure member ( 4 ) which is elastically malleable, mounted to an external periphery of the tube ( 1 ), and separated radially from the pipeline (K), in a rest configuration of the device, by an annulus (EA) providing the fluid with a peripheral circulatory passage (CP), said annular valve closure member ( 4 ) being subject to, in the event of excessive flow rate of the fluid, a radial expansion by which it is pressed against the pipeline (K) and obstructs the peripheral circulatory passage (CP);
wherein said device changes between the rest configuration, which the device adopts in the event of a normal fluid flow rate and in which the central valve ( 3 ) frees the central circulatory passage (CC), and a safety configuration, which the device adopts in the event of an excessive fluid flow rate and in which the central valve ( 3 ) obstructs the central circulatory passage (cc).
2. Safety device according to claim 1 , wherein the valve seat ( 30 ) is supported by the downstream end ( 10 ) of the tube ( 1 ).
3. Safety device according to claim 1 , wherein the central valve closure member ( 31 ) is integral to a valve rod ( 33 ) on which the spring ( 32 ) acts.
4. Safety device according to claim 3 , wherein the central valve closure member ( 31 ), the valve rod ( 33 ) and the spring ( 32 ) are placed upstream from the tube ( 1 ).
5. Safety device according to claim 4 , wherein the device additionally comprises a hollow body ( 5 ) placed in line with the tube ( 1 ) upstream from the tube, in which the valve rod ( 33 ) and the spring ( 32 ) are housed, and which has a downstream end ( 51 ) in relation to which the central valve closure member, the hollow body ( 5 ) and the tube ( 1 ) being longitudinally separated one from the other by a longitudinal space (EL) and providing the fluid with a passage regulated by the central valve ( 3 ) and linking the exterior of the hollow body ( 5 ) to the interior of the tube ( 1 ).
6. Safety device according to claim 1 , wherein the spring ( 32 ) is interposed between an internal abutment ( 52 ) of the hollow body ( 5 ) and an abutment ( 330 ) on the valve rod ( 33 ), said spring ( 32 ) working under compression.
7. Safety device according to claim 1 , wherein the central valve closure member ( 31 ) has a point ( 310 ) turned towards the valve seat ( 30 ).
8. Safety device according to claim 1 , wherein the annular valve closure member ( 4 ) is closer to the downstream end ( 11 ) of the tube ( 1 ) than to the upstream end ( 10 ).
9. Safety device according to claim 1 , wherein the annular valve closure member ( 4 ) has a fixed downstream end ( 41 ) in relation to the tube ( 1 ), and an upstream end ( 40 ), selectively movable along the tube ( 1 ) in the event fan excessive fluid flow rate, the downstream movement of the upstream end ( 40 ) of the annular valve closure member ( 4 ) provoking a radial widening of the annular valve closure member ( 4 ).
10. Safety device according to claim 1 , wherein the annular valve closure member ( 4 ) is made of an elastomer material.
11. Safety, device according to claim 1 , wherein the annular valve closure member ( 4 ) is shaped as a bellows seal that has at least one radial bulge ( 420 ).
12. Safety device according to claim 1 , wherein the annular valve closure member ( 4 ) is shaped as a bellows seal that has at least one radial bulge ( 420 ) and a downstream radial bulge ( 421 ), the downstream radial bulge ( 421 ) having at least one air flow path ( 421 a ) allowing the downstream evacuation of fluid present in a volume (V) delimited by the radial bulges ( 420 , 421 ).
13. Safety device according to claim 1 , wherein when the device changes from the rest configuration to the safety configuration, the central valve closure member acts in a reversible manner on the valve seat and the annular valve closure member acts in an irreversible manner on the pipeline (K).
14. Safety device according to claim 5 , wherein the retention device comprises multiple claws fixed to the upstream end ( 50 ) of the hollow body ( 5 ) and moved by an elastic force towards a radial deployment configuration equivalent to spokes of an open umbrella.