Abstract: An indicator device utilizes a pair of magnets to provide a missing-element indication. The indicator may be installed within a filter assembly such that, when a filter element is present, it urges a piston disposed towards the top of the indicator and one of the magnets to slide axially inwards through the indicator's housing and attract the second magnet. The latter then causes a button disposed at the bottom of the indicator to move axially inwards, such that no missing-element indication is provided. When the filter element is removed or is missing, the piston moves axially outwardly, thereby either reducing the force of attraction, or increasing the repulsive force, between the two magnets and causing the button to pop out through the indicator's bottom end and provide visual indication of a missing-element condition. The indication may also be provided as a remote electrical signal, which may be transmitted wirelessly.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time reducing the weight by as much as 50% from a conventional design approach.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time reducing the weight by as much as 50% from a conventional design approach.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time may reduce the weight by as much as 50% from a conventional design approach.

Abstract: A differential pressure indicator has a housing with at least two ports in the housing. One port receives a first pressure, and the second port receives a second pressure. A pressure resistive device is placed between the first port and the second port. The pressure resistive device changes its position when the first pressure exceeds the second pressure by a predetermined amount. A magnet is coupled to the pressure resistive device. A digital displacement sensor senses the position of the magnet. The digital displacement sensor is in communication with an electronic indicator. The electronic indicator activates when the first pressure exceeds the second pressure by a predetermined amount.

Abstract: A method of determining fouling of a filter includes the use of a differential pressure indicator which has a housing with at least two ports in the housing. One port receives a first pressure, and the second port receives a second pressure. A pressure resistive device is placed between the first port and the second port, and changes its position when the first pressure exceeds the second pressure by a predetermined amount. A magnet is coupled to the pressure resistive device. A digital displacement sensor senses the position of the magnet and is in communication with an electronic indicator. The electronic indicator activates when the first pressure exceeds the second pressure by a predetermined amount, thus allowing determination of filter fouling.

Abstract: A replaceable cartridge type dual stage bypass valve is used in dual filter multi-media filtration assemblies. The cartridge may be selected and easily replaced to meet the various combinations and requirements of the dual filter elements (primary and secondary). The individual bypass valves that form the dual stage bypass valve may each be responsive to a predetermined increase of pressure due to a clogged filter condition. The individual bypass valves may use replaceable coil springs. The spring force of the coil spring is determined by the pressure differential to be resisted, i.e., the resistance to be offered by the spring action of the spring, and the flow capacity at a given pressure differential.

Abstract: A differential pressure indicator has a housing with at least two ports in the housing. One port receives a first pressure, and the second port receives a second pressure. A pressure resistive device is placed between the first port and the second port. The pressure resistive device changes its position when the first pressure exceeds the second pressure by a predetermined amount. A magnet is coupled to the pressure resistive device. A digital displacement sensor senses the position of the magnet. The digital displacement sensor is in communication with an electronic indicator. The electronic indicator activates when the first pressure exceeds the second pressure by a predetermined amount.

Abstract: A replaceable cartridge type dual stage bypass valve is used in dual filter multi-media filtration assemblies. The cartridge may be selected and easily replaced to meet the various combinations and requirements of the dual filter elements (primary and secondary). The individual bypass valves that form the dual stage bypass valve may each be responsive to a predetermined increase of pressure due to a clogged filter condition. The individual bypass valves may use replaceable coil springs. The spring force of the coil spring is determined by the pressure differential to be resisted, i.e., the resistance to be offered by the spring action of the spring, and the flow capacity at a given pressure differential.

Abstract: A filter module assembly utilizes a priority valve installed in a manifold to allow for continuous filtration of hydraulic fluid up to a predetermined flow value and diverts occasional high flow to a secondary circuit. This arrangement provides both a low pressure drop at a high flow condition and structural integrity (1,000,000 impulse cycles from 0 to 6000 psi) while at the same time may reduce the weight by as much as 50% from a conventional design approach.