Dripless purification manifold and cartridge

A cartridge based water purification and filtration system which permits cartridge changes without drainage at the input and output ports. Interlocking flanges at the manifold and cartridge lock the cartridge to the manifold and raised surfaces at the cartridge operate the inlet valve with a rotational seating of the cartridge. A spring biased inlet valve depends from a supply manifold input port and cooperates with the filter cartridge to prevent forward flow until the cartridge is seated to the manifold. The check valve includes a split stem which prevents chatter with valve operation. A check valve at the output port cooperates with a sealed bayonet fitting that mates to a concentric outlet port at the cartridge to prevent back flow with cartridge removal. The cartridge also comprises an inlet/outlet means being a two-stage recess wherein a first cylindrical stage presents a first mating surface for mating with the manifold and a second substantially cylindrical stage presenting a second mating surface for mating with the manifold. Both the first and second mating surfaces are substantially continuous and free of interruption by fluid seals.