Patent ID: 7431852

Claim:
A separator to separate a heavier liquid from a mixture of the heavier liquid and a lighter liquid with which the heavier liquid is immiscible comprising an outer housing having an inner volume and an inner housing within the outer housing, a first port in the inner housing from outside the outer housing adapted to be connected to receive an influent flow of a mixture of heavier liquid and lighter liquid, a second port from the inner housing adapted to be connected to discharge the heavier liquid from the inner housing to outside the outer housing positioned such that the second port defines a static liquid level in the inner housing, and an outlet in the inner housing to the inner volume of the outer housing positioned in the inner housing above the static liquid level in the inner housing so that the lighter liquid held in the inner housing can flow to the outlet and so that as surges of influent flow are received in the inner housing and temporarily raise the liquid level in the inner housing above the static liquid level, lighter liquid on top of the heavier liquid in the inner housing is discharged from the outlet to the inner volume of the outer housing, and a supplemental separator in the outer housing to remove lighter liquid from the inner volume, wherein the inner housing has sufficient symmetry from the first port to the second port so the first and second ports are interchangeable, so that the separator can be connected to receive the mixture of the heavier liquid and a lighter liquid at either port, with the heavier liquid being discharged from the inner housing through the other of the ports.