Patent EA-001303-B1 (EA)
Title: Fluid-activatable shut-off device
Inventor: EIELSEN JAN INGE
IPC: F16K17/34
Filed: 1998-05-19
Abstract: 1. Fluid activatable shut-off device in an embodiment as a shut-off valve comprising a valve housing (1), formed with a flow passage (2) therethrough of desired cross-sectional shape, and a movably supported valve body (3) which is moveable between an open valve position, in which the valve body (3) is mainly withdrawn from the flow passage (2), which is thereby essentially cleared, and a closed valve position, in which the valve body blocks the flow passage (2) and closes the valve, characterized in that the valve body (3) is formed and supported so that in the open position of the valve, it projects into the flow passage (2) by a relatively small portion (7) which is thereby subjected to the flow of a fluid passing through the flow passage (2) in a defined flow direction (Q) when the valve is open, which portion (7) of the valve body (3) by open valve projecting into the flow passage (2), is arranged to respond to abnormal flow conditions of the fluid in the flow passage (2), so as to be affected by increased fluid flow rate, changed fluid viscosity and/or temperature, so that the portion (7) and thereby the whole valve body (3) is caused by the fluid to move towards the closed position. 2. Fluid-activatable shut-off device according to claim 1, characterized in that the valve body (3) is supported in a valve housing (1) which in its open position forms a first chamber (4) filled with a hydraulic/pneumatic fluid and communicating with a second chamber (6) through choke channels (5), so that in the closing movement of the valve body (3) the hydraulic/pneumatic fluid is forced from the first chamber (4) into the second chamber (6) through choke channels (5). 3. Fluid-activatable shut-off device according to claim 1, characterized in that the valve body (3) is equipped with plugs (19) which during the closing movement sequentially shut off choke channels (5) to the passing of hydraulic/pneumatic fluid between the chambers (4, 6) to lower the closing speed in the final phase of the closing movement. 4. Fluid-activatable shut-off device according to any one of the preceding claim, characterized in that a portion (7) of the valve body (3), projecting into the flow passage (2) in the open position of the valve, has a convex curvature at its upstream end relative to the direction of flow (Q) of the fluid. 5. Fluid-activatable shut-off device according to any one of claims 1-3, characterized in that the portion (7) of the valve body (3), projecting into the flow passage (2) by open valve, has an angled portion at its upstream end relative to the direction of flow (Q) of the fluid. 6. Fluid-activatable shut-off device according to any one of the preceding claims 2-5, characterized in that a valve bed (9) for slidably receiving the valve body (3), essentially has the form of a cylinder section, and that the valve body (3) mainly has a corresponding circumferential shape. 7. Fluid-activatable shut-off device according to claim 6, characterized in that the valve body (3), formed partially as a cylinder section, is pivotally supported in the valve housing (1) in which there is formed, for this purpose, a central cylindrical bed (9), in which the valve body (3) is slidably supported and which is connected to the remaining part of the valve body (3). 8. A fluid-activatable shut-off device according to claim 7, characterized in that said cylindrical bed (9) forms at least part of that portion (7) of the valve body (3) which by the open valve projects into the flow passage.