AUTOMATIC UNIT FOR EMERGENCY CLOSING COCK IN MAIN GAS LINES Russian patent published in 2003 - IPC

FIELD: manufacture of fittings; transportation of gases via main pipe lines. SUBSTANCE: proposed automatic unit includes distributor with spool valve fitted in its body in form of piston and first and second control chambers connected with gas line. Gas line is provided with shut-off member connected with hydraulic drive. Control cavity of hydraulic drive is connected with outlet chamber and membrane. Piston is mounted in body between first and second chambers on upper and lower rods of opposite direction. Rods are secured for axial displacement in sealed bushed fitted in lower cover of body and in partition between second control chamber. Second control chamber is divided into two cavities by means of metal membrane pressed between upper end face of body and cover and is connected with control cavity of shut-off member drive. Upper rod has cone-shaped head; diameter of base of this head exceeds diameter of cylindrical part of rod; it is mounted in immediate proximity of membrane to ensure its bursting. First and second control chambers are brought into communication via calibrated through orifices. First control chamber is connected with ballast reservoir connected in its turn with gas line through check valve. Under-membrane cavity of outlet chamber is connected with emergency gas storage tank and with gas line through check valve. Upper and lower covers of body have holes communicating respectively outlet chamber and cavity under end face of lower rod with atmosphere. EFFECT: avoidance of gas leakage and false operation of automatic unit; enhanced reliability and safety. 2 cl, 2 dwg