GB1250287A - - Google Patents

Abstract

1,250,287. Pressure testing containers. WERNER & PFLEIDERER. Feb. 13, 1970 [March 22, 1969], No.7086/70. Heading G1S. A method of and apparatus for pressure liquid testing a container 11 employs, a hydraulic pump 2 and non-return check valve 4 supplying water to supply pipe 6 and a hydraulic accumulator 1, an air compressor 3 supplying air at maximum test pressure to cylinder 9 and water tube level gauge 7 and air at minimum test pressure to cylinder 10 and water tube level gauge 8, and sets of electrical contact switches 15-19 in each gauge tube operating test water supply and exhaust valves to the container 11. The compressed air acts as a reserve force in the system since liquids are not compressible, otherwise the liquid pressure in the container 1 and water level tubes 7 and 8 would drop to zero upon the slightest withdrawal or loss of fluid. The compressed air reservoirs of the containers 1, 9 and 10 are connected by a ring main to the compressor 3. In operation, when a stop valve 21 is opened, water already in 11 is subjected to the maximum water pressure in the gauge 7. This causes a float (not shown) to sink in the gauge 7 and operate switches 17, 16 which open valves 22, 23 and provide a direct supply connection to the accumulator 1. The pressure is thus raised again in the container 11 and gauge 7 and the float rises to shut supply valves 22, 23, and maintain the pressure within a limited range. When the period for testing at maximum pressure is completed the valve 21 is closed and this automatically opens valve 25 to connect the minimum pressure gauge 8 to the container so that a further but lower pressure test may be carried out on 11. Similar float operated switches 15<SP>1</SP>-19<SP>1</SP> are operated in gauge 8 to maintain the lower pressure also within a desired range. Contacts 15 and 19 in each gauge prevent compressed air from escaping or the water level from rising too far, and in the event of the maximum pressure being exceeded a contact 18 opens the exhaust valve 24.