System and method for leak detection based on prv outlet pressure monitoring

Abstract

A leak detection system for a building includes a pressure regulating valve (PRV) having a PRV inlet and a PRV outlet. The PRV is operative during a flow of water through the PRV, and a PRV pressure at a lockup pressure during no water flow through the PRV. An outlet pressure sensor is fluidly coupled to the PRV outlet to measure a PRV outlet pressure. A processor is operatively coupled to the outlet pressure sensor. The processor is configured to run a pressure monitoring process to detect changes in pressure at the PRV outlet when the PRV pressure falls below the lockup pressure while remaining above a setpoint pressure to give an indicia of a fixture leak. A method to give an indicia of a fixture leak is also described.

What is claimed is: 
     
         1 . A leak detection system for a building comprising:
 a pressure regulating valve (PRV) having a PRV inlet and a PRV outlet, said PRV operative during a flow of water through said PRV, and a PRV pressure at a lockup pressure during no water flow through said PRV;   an outlet pressure sensor fluidly coupled to said PRV outlet to measure a PRV outlet pressure; and   a processor operatively coupled to said outlet pressure sensor; said processor configured to run a pressure monitoring process to detect changes in pressure at said PRV outlet when said PRV pressure falls below said lockup pressure while remaining above a setpoint pressure to give an indicia of a fixture leak.   
     
     
         2 . The leak detection system of  claim 1 , further comprising an inlet pressure sensor fluidly coupled to said PRV inlet, and operatively coupled to said processor. 
     
     
         3 . The leak detection system of  claim 2 , wherein said pressure monitoring process to detect a drift of a PRV setpoint outlet pressure. 
     
     
         4 . The leak detection system of  claim 2 , wherein said pressure monitoring process to detect a failure or onset of said failure of said PRV. 
     
     
         5 . The leak detection system of  claim 1 , further comprising a pressure control valve controlled by said PRV, said PRV acting as a pilot PRV. 
     
     
         6 . The leak detection system of  claim 5 , wherein said pressure monitoring process to detect a failure or onset of said failure of said pressure control valve. 
     
     
         7 . The leak detection system of  claim 1 , further comprising an isolation valve fluidly coupled downstream of said PRV. 
     
     
         8 . The leak detection system of  claim 7 , wherein said isolation valve comprises a manually controlled isolation valve. 
     
     
         9 . The leak detection system of  claim 7 , wherein said isolation valve comprises an automatic controlled isolation valve operatively coupled to a processor to periodically close said isolation valve during times of water system no use or times of no occupancy of a home or building. 
     
     
         10 . A method to give an indicia of a fixture leak comprising:
 providing a pressure regulating valve (PRV) having a PRV inlet and a PRV outlet, said PRV operative during a flow of water through said PRV, and said PRV pressure at a lockup pressure during no water flow through said PRV, an outlet pressure sensor fluidly coupled to said PRV outlet to measure a PRV outlet pressure, a processor operatively coupled to said outlet pressure sensor said processor configured to run a pressure monitoring process; and   detecting changes in said PRV outlet pressure at said PRV outlet when said PRV pressure falls below said lockup pressure while remaining above a setpoint pressure to give an indicia of the a fixture leak.   
     
     
         11 . The method of  claim 10 , wherein said step of providing further includes providing said inlet sensor at said PRV inlet, and said step of detecting comprises detecting changes in said pressure at said PRV outlet and said PRV inlet when said PRV pressure falls below said lockup pressure while remaining above said setpoint pressure to give an indicia of said a fixture leak. 
     
     
         12 . The method of  claim 10 , wherein said step of providing further includes providing said isolation valve fluidly coupled downstream of said PRV, and before said step of detecting further comprises said step of stopping said flow of water through said PRV to determine a current lockup pressure. 
     
     
         13 . The method of  claim 12 , wherein said step of stopping said flow of water comprises stopping said flow during a time of no home or building occupancy, to measure said lockup pressure. 
     
     
         14 . The method of  claim 12 , wherein said step of stopping said flow of water comprises automatically closing said isolation valve by said processor during a time of no home or building occupancy.