Patent ID: 8947242
Filing Date: 2015-02-03
Classification: F16K,F23N,G01M,Y10T

Abstract:
1. A valve assembly for controlling fuel flow to a combustion appliance, the valve assembly comprising: a valve body having an inlet port and an outlet port, with a fluid path extending between the inlet port and the outlet port; a first valve situated in the fluid path between the inlet port and the outlet port; a second valve situated in the fluid path between the inlet port and the outlet port downstream of the first valve, with an intermediate volume between the first valve and the second valve defined by the valve body; a first valve actuator, secured relative to the valve body, for selectively moving the first valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a second valve actuator, secured relative to the valve body, for selectively moving the second valve between a closed position, which closes the fluid path between the inlet port and the outlet port, and an open position; a pressure sensor in fluid communication with the intermediate volume between the first valve and the second valve for sensing a measure that is related to the pressure in the intermediate volume; a memory, the memory storing a first threshold value and a second threshold value; a controller in communication with the pressure sensor for determining a measure that is related to a pressure change rate in the intermediate volume; during a first valve leakage test having a first duration, the controller configured to compare a first measure that is related to a pressure change rate in the intermediate volume to the first threshold value; and during a second valve leakage test having a second duration, comparing a second measure that is related to a pressure change rate in the intermediate volume to the second threshold value, wherein the second duration is longer than the first duration.