You don’t have to remove what you don’t allow to enter. Indeed, it’s hard to challenge the logic and value of controlling water ingression, but because moisture is everywhere, achieving bone-dry oil through exclusion alone may not be practical or even necessary. Lubricating oils have different degrees of hygroscopicity (water-loving tendencies), making the control of all dissolved water an almost futile exercise. However, for many applications, it’s the free and emulsified water that is the most destructive and, hence, the central target for control and inspection.
