Patent ID: 9074770
Filing Date: 2015-07-07
Classification: F23N,G01M,Y10T

Abstract:
1. A valve assembly for controlling fuel flow to a combustion appliance, the combustion appliance cycling on and off during a sequence of operational cycles, at least some of the operational cycles of the combustion appliance each performing a valve proving test prior to and/or after igniting the fuel during the operational cycle, 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 a pressure in the intermediate volume; a controller, secured relative to the valve body and in communication with the pressure sensor, the controller configured to determine a measure that is related to a pressure in the intermediate volume during each valve proving test that is performed as part of at least some of the operational cycles of the combustion appliance; wherein the controller is configured to compare the measure that is related to the pressure in the intermediate volume to a first sub-test threshold value during a first sub-test of the valve proving test; and the controller is further configured to compare the measure that is related to the pressure in the intermediate volume to a second sub-test threshold value that is a different value than the first sub-test threshold value during a second sub-test of the valve proving test.