Effluent pipe gate valve has float mechanism with catches and spring to close it automatically in event of backflow

摘要

The gate valve, set in a pipe carrying effluent or other liquid, has a shutter closed by a handwheel (V). When the valve is opened an arm connected to the handwheel compresses a spring (R1) which is then held in place by a catch on a float mechanism (D1, D2). In the event of a backflow through the pipe the float mechanism causes the catch to release the spring, which automatically closes the valve.