Pressure limited differential pressure switch

摘要

A differential pressure switch includes a housing which carries a switch assembly which is actuated by movement of a differential pressure responsive piston slidable within the housing. The piston shifts in response to pressure differentials between the pressure levels in the chambers defined between the ends of the piston and the corresponding ends of the housing. The piston includes a pressure responsive stop that responds to pressure levels above a predetermined pressure level to engage the housing to thereby prevent shifting of the piston and actuation of the switch assembly regardless of the pressure differential across the piston, thereby limiting operation of the pressure switch to pressure levels below the predetermined maximum pressure level.