Abstract: The present invention discloses an improved center pivot for a self-propelled center pivot irrigation system. The preferred embodiment is characterized by a vertical pivot pipe supported for rotational movement at both the upper and lower extremities thereof. Additionally, the gasket assembly providing leak-proof rotational movement of the pivot pipe relative to a fixed liquid supply pipe is characterized by a slideable casing which can be moved from a normal operating position wherein the fixed supply pipe and the rotating pivot pipe are bridged by the casing with gaskets disposed between mating surfaces and a second non-bridged position wherein the gaskets are removable so as to allow replacement of worn gaskets without moving or removing any of the major pipe components of the sprinkler system.