Ring body, pipe joint, and method for joining pipes using the ring body

A ring body which is to be provided in a pipe joint, the pipe joint comprising:

• a spigot formed in a first pipe;
• a socket formed in a second pipe;
• a lock ring accommodation groove formed in an inner circumference of the socket;
• a lock ring accommodated in the lock ring accommodation groove;
• and
• a seal ring which, at a location that is closer to an opening end of the socket than the lock ring, is compressed in a pipe radial direction to seal a space between an outer circumference of the spigot and the inner circumference of the socket,
• the socket having, at the inner circumference, a socket sealing surface with which an outer circumferential surface of the seal ring contacts with pressure over the entire circumference, and a socket protrusion that protrudes inward in the pipe radial direction from a deeper portion of the socket sealing surface,
• an inner diameter of the socket sealing surface being larger than an inner diameter of the socket protrusion,
• a spigot engagement portion being formed at the outer circumference of the spigot, and
• in a state in which the spigot is inserted in the socket, separation of the spigot from the socket can be prevented by the spigot engagement portion being caught on the lock ring from a deeper portion of the socket in a separation direction of the spigot,
• the ring body comprising:
• an annular ring main body portion that can be inserted between an inner circumferential surface of the socket protrusion and an outer circumferential surface of the spigot;
• and
• a plurality of interval maintaining parts that can be inserted between the socket sealing surface and the outer circumferential surface of the spigot, wherein
• the plurality of interval maintaining parts are provided in the ring main body portion at predetermined intervals in a pipe circumference direction,
• by the plurality of interval maintaining parts being inserted between the socket sealing surface and the outer circumferential surface of the spigot, the plurality of interval maintaining parts maintain an interval between the socket sealing surface and the outer circumferential surface of the spigot in the pipe radial direction at a predetermined size that allows the seal ring to be pushed in, and
• a escape space into which a distal end portion of the seal ring that is compressed can enter is formed at a location which is between one interval maintaining part and another interval maintaining part that are adjacent in the pipe circumference direction and which is closer to a socket opening end than the ring main body portion.