Coupling with improved elastomeric face seal

Claim 1

A coupling including a pair of coupling bodies each adapted for sealing engagement with respective ends of a fluid line at an axially outward end of the coupling body and having a central passageway for fluid-tight tight transmission of fluid between and mated coupling bodies, the coupling further including locking means to secure the coupling bodies axially together in a coupled position and for releasing the coupling bodies to an axially separated uncoupled position, and an elastomeric annular seal housed in a sealing end of each coupling body for sealing engagement with its respective coupling body and with the other seal when the coupling bodies are mated together, the coupling further comprising: each coupling body having an annular recess in the sealing end of each coupling body defined by a recess base surface of the coupling body, an outer wall portion of the coupling body, and an open end; an annular securing member extending radially inward from the outer wall portion of the coupling body and having an end surface for engagement with the annular seal; and the annular seal having a preselected thickness and being configured to fit within the annular recess, and having a cross-sectional configuration which defines: (a) a tapered upper surface projecting radially inward and axially from its respective coupling body at an angle of from 13° to 17° with respect to a radial planar surface for sealing engagement with the tapered upper surface of the other seal when the coupling is mated; (b) a radially inward concave surface having a selected radius of curvature with its center positioned radially inward thereof and having a ratio between the radius of curvature and the thickness of the annular seal which establishes a compression factor of 80-92%; and (c) a radially outward projection positioned adjacent the outer wall portion and axially between the securing member and the base surface of the coupling body.