Very low temperature flow switch apparatus
OwnerKevin Flynninventor
Life of this patent
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Abstract
Flow in a forward direction through a check valve is detected by a signaling device in parallel with the check valve and sensing the pressure differential across the check valve. The signaling device outputs an electrical signal that indicates whether or not the pressure differential across the valve is sufficient to open the valve to flow. A flow restrictor such as a capillary tube is in parallel with the check valve to by-pass a small portion of flow during normal operation and to equalize pressure across the check valve inlet and outlet when the check valve is otherwise closed to flow.
Claims10
A flow switch apparatus indicating whether or not fluid is flowing in said apparatus, comprising:
- a check valve having an inlet and an outlet, fluid pressure at said inlet being greater than pressure of said fluid at said outlet in a first mode when said valve is open to fluid flow, said valve being closed to flow in a second mode when said outlet pressure is one of equal to and greater than said inlet pressure;
- a signaling device for detecting whether said valve is in said first or second mode and outputting a corresponding electrical signal;
- a throttle device in parallel with said check valve by connection across said valve inlet and outlet, said throttle device by-passing a portion of said fluid flow in said first mode, said throttle device permitting pressure equalization at said valve inlet and outlet when said valve switches from said first mode to said second mode.
Dependencies are inferred from the claim text.