A seal assembly for sealing an annular space between a first cylindrical surface and a second cylindrical surface. The annular space has high pressure zones and low pressure zones. The seal assembly has an annular seal with an inner surface that faces the second cylindrical component, an outer surface that faces the first cylindrical component, a sealing end and an engagement end. A seal actuator assembly applies a force to the engagement end of the annular seal to urge the annular seal in a first direction towards an engaged position within the annular space. The force applied to the engagement end of the annular seal has a first component aligned with the first direction and a second component that is perpendicular to the first direction. The first component is at least 1.7 times greater than the second component.