Air and fluid leakage detector and warning system for single-walled chemical storage tanks - has microcomputer for monitoring pressure rise and fall in vacuum-pumped test space surrounding container

摘要

A storage tank (10) has a plastic leak-proof lining (13) within a single-walled vessel, with the gap between lining and vessel (11) forming a test space monitored by an air line (15) and valve (16). The line contains a liquid trap (32). A vacuum pump (18) pumps out the test space at regular intervals under control of a microcomputer (25). An alarm or control signal is set if the following occur: evacuation time is less than the normal time and/or the evacuation time is greater than normal and/or if the pressure rise after evacuation is faster than normal and/or if the pressure rise after evacuation is slower than normal and/or if the pressure rises above a maximum threshold. In the event of a combination of alarms, the vacuum pump is switched off. USE - Monitoring installations for hazardous or inflammable chemical storage tanks.