Abstract: A flow restricting device is described which includes a conduit with a flow inhibitor therein. A plug stem is placed inside a passage in the inhibitor such that it can slide axially, while the head of the plug, which has a larger cross-sectional area than the passage, remains outside the passage. When the fluid pressure upstream of the flow inhibitor is greater than the fluid pressure downstream thereof, the head of the plug is forced against the face of the inhibitor and flow is restricted. To facilitate resetting of the inhibitor, the head allows a small amount of flow to pass to the downstream side, thereby equalizing the pressure across the device.