Patent ID: 7699069

Claim:
A valve apparatus comprising: a valve having a valve body with first and second valve chambers connected to respective valve ports and joined by an intermediate passage, the valve being selectively configurable in: i) a first open configuration in which the intermediate passage is open and the first and second valve chambers are interconnected by the intermediate passage, ii) a second closed configuration in which the intermediate passage is closed by first and second seals seated at respective locations in the passage to seal respectively between the first and second valve chambers and a first leakage chamber at the portion of the intermediate passage between the two seals, or iii) a third cleaning configuration in which one of the two seals is unseated to connect a respective one of the first and second valve chambers to the first leakage chamber, while the other of the two seals remains seated; a valve actuator adapted for selectively setting the valve to any one of the three configurations in response to respective control signals a flow sensor connected to the first leakage chamber and adapted to provide a flow sensor output signal that is indicative of a leakage flow from the first leakage chamber; and a valve controller having at least one signal input port to which the flow sensor output signal is connected, wherein the valve controller is adapted to: provide at least one control signal to the valve actuator for setting the valve to a respective one of the three configurations, respond to the flow sensor output signal and make a comparison between the leakage flow as indicated by the flow sensor output signal and a predetermined flow from the first leakage chamber associated with the selected valve configuration, and provide a controller output signal that is responsive to the comparison and is indicative of the presence or absence of a desired valve function or an undesired valve dysfunction.