Air leakage monitor multiple cables - signals failure to reopen cock after repair and detects faults in other lines during repair

摘要

The system allows monitoring of cables fed from the same air source as the cut-off line during repair and signals failure to open the cock after repair. A leakage fault on a cable (C1,.......,Cn) leads to the emission of an electric signal by the flow meter (SD) to initiate an alarm sequence in which audible (21) and visual (22) signals are activated, and the stop cock(R) is automatically or manually closed, which cuts off the audible alarm and leaves the alarm lamp (22) permanently on. If after repair the cock is not opened the alarm lamp (22) remains on. If a fault occurs on another line during repair the flowmeter operates a monostable circuit(M) output is inverted by an amplifier (12) to drive an AND gate (13) whose other input is from an OR gate (10) fed by each of the detectors, cutting off the alarm for the monostable On time, then restoring it,.