Abstract: A differential fluid pressure indicating device for use in conjunction with a filter body carrying a filter element which provides an exteriorly visible signal when the differential pressure across the filter element exceeds a predetermined amount. The device comprises a housing having a cylindrical chamber in which a rotationally constrained piston is axially slidably disposed and movable between a first and second axial position while resilient means urge the piston towards its first axial position. The inlet fluid pressure communicates with one axial end of the piston while the outlet fluid pressure communicates with the other axial end of the piston. When the differential pressure across the filter element exceeds a predetermined value, the inlet fluid pressure moves the piston from its first to its second axial position and releases a spring loaded exteriorly visible member which rotates from a first to a second rotational position.

Abstract: A fluid filtering device is provided which is particularly suitable for connection with the suction line of a hydraulic system. The fluid filtering device comprises an elongated housing open at its upper end and secured to a fluid reservoir so that the lower end of the housing is positioned below the fluid level in the reservoir while fluid outlet means are formed on the lower submerged end of the housing. An annular housing member is coaxially positioned within and secured to the main housing below the fluid level of the reservoir so that the annular housing member is spaced radially inwardly from the main housing thus forming an annular chamber therebetween. The interior of the housing member is open to the filter outlet while fluid passageways through the housing member establish fluid communication between the annular chamber and the fluid outlet.