IMPROVED FITTING WITH SEQUENTIAL SEALING ACTION

A fitting for making connections with a pipe includes a coupling body having an inside surface defining a bore for receiving a pipe. A ring is fitted over the coupling body for sealing and mechanically connecting the coupling body to the pipe. An axisymmetrical main seal is formed on the inside surface of the coupling body that seals and connects to the pipe when the ring is installed on the coupling body. An axisymmetrical inboard seal is formed on the inside surface of the coupling body axially spaced from the main seal that seals and connects to the pipe when the ring is installed on the coupling body. At least one of the coupling body and the ring is configured so that the inboard seal seals and connects after the main seal seals and connects to the pipe. An axisymmetrical outboard seal is formed on the inside surface of the coupling body axially spaced from the main seal that connects to the pipe when the ring is installed on the coupling body. At least one of the coupling body and the ring is further configured so that the outboard seal seals and mechanically connects after the inboard seal seals and connects to the pipe. At least one of the coupling body and the ring is still further configured to apply a restoring load to the main seal to further seal and mechanically connect the main seal to the pipe after the outboard seal seals and connects to the pipe. L~invention concerne un raccord pour tuyau comportant un corps d~accouplement présentant une surface intérieure définissant un alésage destiné à recevoir un tuyau. Un anneau est ajusté sur le corps d~accouplement pour assurer l~étanchéité et raccorder mécaniquement le corps d~accouplement au tuyau. Un joint d~étanchéité axisymétrique principal est formé sur la surface intérieure du corps d~accouplement et assure l~étanchéité du tuyau et se raccorde à celui-ci lorsque l~anneau est installé sur le corps d~accouplement. Un joint d~étanchéité axisymétrique interne est formé sur la surface intérieure du corps d~accouplement et est espacé axialement du joint d~étanchéité principal qui assure l~étanchéité du tuyau et se raccorde à celui-ci lorsque l~anneau est installé sur le corps d~accouplement. L~un au moins du corps d~accouplement et de l~anneau est configuré de façon à ce que le joint d~étanchéité interne assure l~étanchéité et se raccorde après que le joint d~étanchéité principal a assuré l~étanchéité du tuyau et s~est raccordé à celui-ci. Un joint d~étanchéité axisymétrique externe est formé sur