A connector seal device for connecting a branch pipe to a transverse opening of a main pipe, including a hollow elastomer insert of a first material and a pipe union of a harder second material. The elastomer insert may include a flexible support collar, a sealing wall region with a tapered inside surface having first locking ring zones, and an outside surface adapted to fit the transverse opening. The pipe union may include an engagement end with a tapered outside surface having second locking ring zones. The pipe union may include a socket end adapted to cooperate with the branch pipe. When the elastomer insert is inserted into the transverse opening and the pipe union is pushed into the elastomer insert, the first and second locking ring zones engage in the manner of ratchet teeth to press the elastomer insert against the transverse opening.