Cassette

A cassette comprising:

• an inlet cassette plate defining a cassette inlet and an inlet channel in fluid communication with the cassette inlet, the inlet channel extending across the inlet cassette plate, wherein the inlet channel defines an inlet channel depth in an axial direction;
• an outlet cassette plate configured to be arranged in a stack with the inlet cassette plate, the outlet cassette plate defining a cassette outlet opposite the cassette inlet in a longitudinal direction and an outlet channel in fluid communication with the cassette outlet, wherein the outlet channel extends across the outlet cassette plate, wherein the outlet channel defines an outlet channel depth in the axial direction, wherein the inlet cassette plate and the outlet cassette plate define a snap fit;
• a separation layer disposed between the inlet cassette plate and the outlet cassette plate;
• and
• a seal disposed perimetrically around the separation layer axially between the inlet cassette plate and the outlet cassette plate, wherein the snap fit, when engaged, achieves an intermediate seal pressure that is less than an operating seal pressure of the cassette,
• wherein the inlet channel is in fluid communication with the outlet channel through the separation layer to form an assembly flow path, and
• wherein the inlet channel extends along an effective inlet surface area of the separation layer and the outlet channel extends along an effective outlet surface area of the separation layer.