Abstract: Provided is a pipe retaining device, for a pipe fitting, which has a simple structure but is capable of further improving a detachment preventing force for a pipe without inserting an inner core. The pipe retaining device includes an inclination mechanism (7) configured to incline a retaining ring (3A) in a pipe axis direction with respect to a reference plane (P) orthogonal to a central axis of a ring body (30A), such that each circumferential end portion (30x) of the ring body (30A) is caused to be closer to a fitting body (2) and a circumferential center portion (30y) of the ring body (30A) is moved away from the fitting body (2), when each retaining ring connecting portion (32) and each facing portion (54) come into contact with each other. A first surface (56), facing the retaining ring connecting portion (32), of each facing portion (54) is parallel to a reference plane P.

Abstract: Provided is a pipe detachment preventing device, for a union nut pipe fitting, which can omit an inner core and which can prevent detachment of a pipe from a pipe fitting even when a large pulling force which stretches the pipe acts. Connection holding means (7) includes an inclination mechanism (8) configured to incline a retaining ring (4A) in a pipe axis direction (X) with respect to a reference plane (P) orthogonal to a central axis (C) of a retaining ring body (40), such that one of a circumferential center portion (40y) and a circumferential end portion (40x) of a retaining ring body (40A) is caused to be closer to a fitting body (2) and the other is moved away from the fitting body (2), when first protruding portions (41) and first facing portions (55) come into contact with each other and a pipe pulling force which stretches a joint pipe (100) is applied to the joint pipe (100).

Abstract: A pipe coupling device includes: a joint body into which a joining pipe is inserted; a C-ring-shaped retaining ring that includes a flange part protruding from an outer peripheral surface thereof fixed onto an outer peripheral surface of the joining pipe; and a pressing plate having a recessed part for housing the flange part. The retaining ring further includes a second flange part protruding from the outer peripheral surface thereof. The pressing plate further includes a pair of through-holes through which the coupling members penetrate, and a second recessed part for housing the second flange part. The second flange parts are provided with a circumferential center portion of the ring body between them, and the pressing plates are provided with the circumferential center portion between them. The recessed part is located between the through-holes, and the second recessed part is located outward of the through-holes in the circumferential direction.

Abstract: A pipe coupling device includes a joint body, a C-shaped retaining ring that includes a flange part radially protruding from an outer peripheral surface of the retaining ring, a pressing plate that includes a recessed part configured to house the flange part, and includes a front wall configured to face a rear end of the flange part. The joint body, the retaining ring, and the pressing plate are coupled together in an axial direction. The flange part has a substantially rectangular shape extending along the axial direction, and an inclined surface is formed on at least one of the rear end and the front wall. An inner end of the inclined surface is positioned closer to the joint body than an outer end thereof. The inner end is closer to a center axis of the joint body than the outer end. A gap is formed between the rear end and the front wall.