Arrangement of pressure changes in a flow system and procedures for sending a signal in case of pressure changes in a flow system

摘要

1308722 Testing pipelines for leaks TEXTRON Inc 3 Aug 1971 [17 Aug 1970] 36375/71 Heading G1S [Also in Division G3] In a system for monitoring pressure in a pipeline to detect fracture of the pipeline, an additional drop in pressure occurring during a predetermined time interval after detection of an initial predetermined pressure drop is separately detected to initiate, e.g. closure of a valve, stoppage of a compressor or sounding of an alarm. In the system shown, selector valve 17 admits the higher of upstream and downstream pressure at valve 10 in pipeline 11 to line 23 connected to accummulators 22, 24 via check valve 28 and valve 43 respectively. When an initial pressure drop occurs in the pipeline, this is applied due to check valve 28 across valve 30 causing the latter to admit fluid from line 18 to valve 32 which in turn admits fluid from line 18 to valve 43 which shifts to disconnect accumulator 24 from line 23 thereby retaining the current line 23 pressure in accumulator 24. Valve 43 also acts to bypass check valve 28 whereby valve 30 is immediately reset and valve 32 resets over a period determined by restrictor 41. Valve 43 meanwhile remains in a position isolating accumulator 24, and valve 44 will thereby respond to any further predetermined drop in line 23 pressure which may occur and will supply fluid from line 18 to motor 12 to close valve 10. If valve 44 does not operate in the time allowed by restrictor 41, the valve 43 resets and the system monitoring cycle can then repeat. Manual control of valve 10 is provided by valves (19, 20).