An elastomeric seal seals a pipe which is held in a push-in part of a plug-in coupling relative to a cylindrical interior surface of a housing of the plug-in coupling, into which the push-in part is pushed together with the pipe. The seal is in prestressed contact with the interior surface of the housing...http://www.google.es/patents/US6454314?utm_source=gb-gplus-sharePatente US6454314 - Seal for a plug-in connection
