Environmentally friendly dual lube venturi filter cartridge

An environmentally friendly dual lube filter cartridge containing no metal parts, and comprising in combination:

• a non metallic venturi centertube having a venturi throat and at least one venturi port,
• a bypass filter coaxial with the venturi centertube, and a first flow passage between the bypass filter and the venturi centertube for dual filtered fluid,
• a full flow filter having a non-metallic centertube and mounted coaxial with the bypass filter, the full flow centertube having a bore which is larger than the outer periphery of the bypass filter to create a second flow passage for single filtered fluid,
• a first plastic endcap sealing an end of the bypass filter to an end of the venturi centertube, the first endcap having standoffs for creating a flow path for single filtered fluid from the second flow passage to the venturi centertube,
• a second plastic endcap joining the full flow filter, the bypass filter and the venturi centertube, the second endcap having a central passage connected to the venturi centertube for flow of fluid from the cartridge, the second endcap also having an annular groove for receiving a skirt-like radial seal gasket positioned near the periphery of the full flow filter, and
• a third endcap enclosing the upper end of the cartridge and sealingly joined to the full flow filter element, the standoffs on the first endcap providing flow passages between the bypass element and the third endcap, the third endcap having an annular peripheral groove for carrying an axial seal gasket.

An environmentally friendly dual lube filter cartridge containing no metal parts, and comprising in combination:

• a cylindrical bypass filter element mounted coaxially around a plastic venturi centertube,
• a cylindrical full flow filter element surrounding and concentric with the bypass filter, and providing a flow path between the full flow and bypass filters, and
• a maximum of three plastic endcaps sealing the ends of both said filter elements and including:
• a first substantially planar endcap sealing the first ends of both the full flow and bypass filter elements in a common plane,
• a second internal plastic endcap sealing a second end of the bypass filter and providing concentric standoffs within a bore of the full flow filter,
• a third plastic endcap sealing the second end of the full flow filter and the standoffs, whereby the standoffs provide a flow path between said flow path and the centertube, and
• the third endcap having a pressure relief aperture for limiting deflection of the plastic endcap caused by differential pressures in use.