Patent ID: 8640724

Claim:
A valve control system, comprising: a first valve arranged in a flow path configured for a flow of fluid, said first valve being openable and closable according to a first electric signal; a second valve arranged in said flow path at a position downstream of said first valve, said second valve being openable and closable according to a second electric signal; a first sensor arranged in said flow path, and positioned between said first and second valves to detect a state of fluid flowing from said first valve; a second sensor arranged in said flow path, and positioned downstream from said second valve to detect a state of fluid flowing from said second valve; and a safety controller configured: to control said first and second valves based on a result of detection of said first sensor and a result of detection of said second sensor, and to check that the result of detection of said first sensor indicates that fluid is not flowing from said first valve and that the result of detection of said second sensor indicates that fluid is not flowing from said second valve.