DEVICE STRUCTURE METAL PIPE ( D.1/2 ) (L. 25 CM ) ASSEMBLE WITH DIMENSION OF MAIN GAS LINE METAL PIPE ( D.1/8 ) ( L.50 CM ) STRUCTURE BETWEEN PIPE1/2 AND INLET SOLENOID VALVE METAL PIPE ( D.1/8 ) ( L. 50 CM ) STRUCTURE BETWEEN SOLENOID VALVE AND ( P.C.V. PNEUMATIC ) GAS LEAKAGE DETECTOR ATTACHED WITH ALARM PHONE AND SOLENOID VALVE . DEVICE WORKING WHEN OCCURRENCE GAS LEAKAGE – THE DETECTOR SEND TO ( TWO SIGNAL ELECT. ) TO ALARM PHONE AND SOLENOID VALVE . SOLENOID VALVE OPEN INLET GATE AND THE GAS TRANSFER TO P.C.V. PNEUMATIC TO CLOSE MAIN SOURCE OF GAS LINE . NOTICE BEFORE AGAIN OPERATING SYSTEM MUST BE RELEASE GAS PRESSURE BETWEEN SOLENOID VALVE AND ( P.C.V. PNEUMATIC ) THROUGH MANUAL VALVE STRUCTURE BETWEEN SOLENOID AND P.C.V