GB1299783A - Method of, and apparatus for charging a thermostatic system - Google Patents

Abstract

1299783 Temperature responsive actuating devices; testing for leaks DANFOSS A S 30 April 1970 [7 May 1969] 20796/70 Headings G1D and G1S A thermostatic system is charged firstly with a substantially non-condensable medium such as nitrogen and subsequently with a condensable medium. As shown, the system which comprises a temperature sensor 1 connected by a capillary tube 3 to a chamber 5 provided with a diaphragm 6 is connected by way of pipes 12, 20, magnetic valves 17, 18, 22 and a reducing valve 14 to a container 13 containing nitrogen under pressure and is also connected by way of further pipes and valves to either a container 23 or container 31 containing a condensable medium. In use, the thermostatic system is flushed with nitrogen by suitably actuating the valves 17, 18, 22 and further valves 19, 36, 37 which allow escape of gas to the atmosphere or the pressure to be suitably reduced in the system by operating a vacuum pump 38. When the system has been flushed and the gas pressure therein reduced to a required pressure as indicated on a gauge 21 the condensable medium is charged into the system either in liquid form from the container 31 by way of valves 33, 35 and a measuring container 34 or in vapour form from the container 23 by way of valves 24, 26 and 29 and a measuring container 27 provided with a pressure gauge 28, the pressure gauge 28 being arranged, if desired, to automatically open and close the valves 26, 29 at predetermined pressures in the container 27 so that automatic supply of a predetermined quantity of condensable medium can be effected. The thermostatic system may be tested for leaks during the flushing operation by immersing the system in a liquid when the system has been charged with nitrogen under pressure and observing any bubbles indicative of leaks.