Indicators and Switches
Deltadyne® differential pressure devices operate by sensing the differential pressure between ports upstream and downstream of the filter element. The differential pressure acts on a piston/magnet assembly that is contained in the Deltadyne device. When the differential pressure across the internal piston/magnet assembly reaches a preset value, determined by the range spring, the piston assembly moves downward sufficiently to reduce the attractive force between the magnet and indicator button or switch actuator lever. The indicator or switch spring then overcomes the reduced magnetic force to release the button or actuate the switch to signal the need for element change.
A magnet coupling isolates the pressurized fluid from the electrical or mechanical actuator. This eliminates dynamic seals and exposed cams, thus avoiding a leakage point common to other types of warning devices, particularly those which are connected to the bypass valve. Deltadyne devices respond only to differential pressures; they can withstand system pressures up to the design limit of 6000 psi (414 bar).