Synthetic resin-made fastening-limiting device for a joint fastening member

A fastening-limiting device for a fastening member, the fastening member being screwed to a pipe receiving port on the side of a joint and fastening a pipe inserted into the pipe receiving port, the pipe receiving port having an outside, wherein said fastening-limiting device comprises:

• a ring portion fitted onto the outside of the pipe receiving port, said ring portion having a beam disposed thereon;
• a first abutting portion disposed on one end face in an axial direction of said ring portion and abuts against a reference face disposed on the side of the joint;
• a protrusion which protrudes from another end face in the axial direction of said ring portion;
• and
• a second abutting portion formed by a tip end of said protrusion, wherein the fastening member has a protruding confronting portion confronting the reference face, the fastening member being screwed to the pipe receiving port and being used for fastening the pipe, said second abutting portion being adapted to abut against the protruding confronting portion, and wherein said protrusion is disposed on said beam portion which is formed by forming a void space in said ring portion, said beam portion and consequently said protrusion being flexibly deformable.