Systems and methods for fuel tank draining and polishing

An assembly comprising:

• a backpressure regulator including a check valve,
• wherein the backpressure regulator is configured to open when pressure of a mixture upstream of the backpressure regulator exceeds a predetermined setpoint, wherein the backpressure regulator is configured to open when a cracking pressure on the backpressure regulator exceeds a predetermined setpoint between 5 psi to 150 psi,
• wherein the predetermined setpoint is determined by a combination of a bubble point pressure of the hydrophobic membrane and an airflow of the hydrophobic membrane, wherein the determining airflow of the hydrophobic membrane is between 0.92 Frazier and 40 Frazier, and wherein the determining bubble point pressure of the hydrophobic membrane is between 20.9 psi and 500 psi;
• a first conduit;
• a hydrophobic membrane comprising ePTFE upstream of the backpressure regulator and downstream of the first conduit,
• wherein the mixture comprises an organic phase liquid and an aqueous phase;
• at least one pump,
• wherein the backpressure regulator is configured to be fluidically connected to and downstream of the first conduit, and to at least one pump operably connected to and upstream of the first conduit;
• a second conduit,
• wherein the hydrophobic membrane is configured to be fluidically connected to and upstream of the second conduit, and
• wherein the second conduit is configured to transport the organic phase liquid downstream of the hydrophobic membrane;
• and
• a third conduit,
• wherein the backpressure regulator is configured to be fluidically connected to and upstream of the third conduit and the third conduit is configured to be downstream the first conduit, and
• wherein the third conduit is configured to transport water downstream of the backpressure regulator.