An asymmetrical orifice for bypass control in a clean fuel module may include a body having first and second end surfaces and an inner surface defining a bore through the body extending from a first opening through the first end surface to a second opening through the second end surface. The first opening has a first opening inner diameter and the second opening has a second opening inner diameter that is less than the first opening inner diameter. The asymmetrical orifice also includes a flow control contour in the second end surface surrounding the second opening of the bore. The configuration may give the asymmetrical orifice a first discharge coefficient for fluid flowing from the first opening to the second opening that is greater than a second discharge coefficient for fluid flowing in a second direction from the second opening to the first opening