Patent ID: 9360213
Filing Date: 2016-06-07
CPC Classification: F23K,F23N,G01M

Claim Text:
1. A leak detecting method for valves supplying a fuel gas to a combustion equipment burner comprising: a first valve that is connected to a pipe of a fuel supplying system and controls a fluid flow rate within the pipe; a second valve that is connected in series to the pipe on the downstream side of the first valve and controls a fluid flow rate within the pipe; a third valve that is connected in series to the pipe on the downstream side of the second valve and controls a fluid flow rate within the pipe; a pressure detector detecting pressure within the pipe between the first and second valves; and a leak detector performing leak detection for the first and second valves, based on a pressure within the pipe, detected by the pressure detector, by controlling the first through third valves individually, wherein: the leak detector performs: a stopped pressure setting step setting the pressure within the pipe between the first and second valves to no less than a first threshold value or to less than a second threshold value by opening and closing the first through third valves individually when the combustion equipment stops combustion or after combustion is stopped; a startup pressure setting step for setting the pressure within the pipe between the first and second valves to no less than the first threshold value by opening and closing the first valve, in a state wherein the second and third valves are closed, when the combustion equipment is started; a first threshold value evaluating step for evaluating whether or not the pressure within the pipe, detected by the pressure detector after a first time interval has elapsed in a state wherein the first through third valves are closed, is at least the first threshold value, after the pressure within the pipe has been set to at least the first threshold value in the stopped pressure setting step or the startup pressure setting step; a second valve normalcy evaluating step evaluating the second valve as operating properly if the evaluation in the first threshold value evaluating step was that the pressure within the pipe is at least the first threshold value, and for evaluating that the second valve is faulty if the evaluation was that the pressure within the pipe is less than the first threshold value; a second threshold value evaluating step evaluating whether or not the pressure within the pipe, detected by the pressure detector after a second time interval has elapsed in a state wherein the first valve and the third valve are closed, is less than the second threshold value, after the pressure within the pipe has been set to less than the second threshold value in the stopped pressure setting step; and a first valve normalcy evaluating step evaluating the first valve as operating properly if the evaluation in the second threshold value evaluating step was that the pressure within the pipe is less than the second threshold value, and for evaluating that the first valve is faulty if the evaluation was that the pressure within the pipe is no less than the second threshold value.