The limit switch is activated by an eccentric cam disc mounted with a set screw on the shaft for lever and weight. The set screw enables adjustment of the cam disc position that gives the signal. Since the disc will move slightly up and down in the flow in open position, it does not make sense to get a signal indicating open position.
Please see datasheet and mounting instruction for further details: Series 41/60-001
Kits containing limit switch and mounting bracket are available as accessories.
The swing check valves can be installed with lever and weight or with bare shaft.