Abstract: A seal face of at least one ring used in a non-contacting, gap-type mechanical end face seal having a pattern including an optional dam and an annular grooved area. The annular grooved area has one of several embodiments, including entrance lands which are essentially triangular and have one side contiguous with one circumferential edge of the annular grooved area. These embodiments further include a set of converging boundary sides of the groove to provide a pressure zone effect. Seal face patterns include a contiguous groove around the circumference of the seal face and a series of annular bands comprising a repeating pattern of an essentially triangular groove interposed between two adjacent, but oppositely oriented, lands.

Abstract: A secondary seal for use in a high temperature environment, including only non-elastomeric elements, includes split high temperature carbon graphite secondary seal rings axially biased by a first set of springs and radially biased by a second set of springs.

Abstract: A controllable mechanical seal for sealing a shaft rotatable relative to the housing of a fluid machine includes first and second face elements having first and second radial surfaces. The first element is adapted for rotation with the shaft. The second element is adapted to be stationary within the housing. One of the elements is movable axially relative to the shaft. The first and second surfaces are adapted to define a gap within which there is a thin lubricating fluid film. An actuator is provided for deforming at least one of the surfaces so that the gap converges in a direction from a high pressure side to a low pressure side of the seal. A sensor is provided for measuring a temperature indicative of incipient contact of said surfaces. A control system responsive to the sensor generates an external voltage which is applied to the actuator to control the convergence of the surfaces and thus maintain an optimum thickness of the lubricating film for a wide range of operating conditions.