A pipe connector having a duct therethrough for connecting a lateral pipe to a well casing and having an inner casing connector provided with a tubular stem which extends through a hole in the well casing wall. Mounted on this stem externally of the casing wall are a casing contacting O-ring gasket, a follower washer, a stem O-ring gasket and a compression nut which compresses the gaskets into fluid - tight engagement with the casing wall and the stem upon which they are mounted. Also annular grooves to partially seat these O-ring gaskets are provided in the faces of the follower washer and/or the gasket confronting face of the nut.