Safety shut-off arrangement

摘要

A safety shut-off arrangement in the supply line of a heating installation heated by a distant heating system comprises a safety valve (26) and a shut-off valve (13). The closing body (18) of the shut-off valve (13) is drive-connected to a piston (21) via a piston rod (20) and an interconnected spring (32). The piston (21) has a throttle bore (23) passing through it and it is guided with play in the housing of the shut-off valve (13), being sealed in relation to the safety valve (26) via a bellows diaphragm (30). The piston (21) has a further valve seat (33) which interacts with a further closing body (34) on the piston rod (20). Normally, the piston (21) is acted upon on one side by the medium pressure in the line (10) and on the other side by the medium pressure in front of the closing body of the safety valve (26), so that when the safety valve responds the piston (21), via the spring (32) and the piston rod (20), brings the closing body (18) of the shut-off valve (13) into the closing position. In the event that the shut-off valve (13) does not close or that an inadmissibly high back pressure exists in the outflow line (11), the further valve (33, 34) can then open and guide off the medium which is under too high a pressure via the safety valve (26) (Fig. 1). <IMAGE>