Push-to-connect-rotate-to-release sprinkler assembly and fitting

A fitting to form a push-to-connect-rotate-to-release (PCRR) coupling of a fire protection sprinkler with a fluid supply pipe fitting, the fitting comprising:

• a first tubular member having a first end, a second end with an outer surface and inner surface to define an internal passageway extending from the first end to the second end along a first longitudinal axis, the outer surface of the first tubular member including a seal member secured about the outer surface and an external helical surface formed along the outer surface and axially spaced from the seal member, the inner surface of the first tubular member including an internal thread for receipt of the fire protection sprinkler;
• a second tubular member with a first end for connection to the fluid supply pipe fitting and a second end for receiving the first tubular member, the second tubular member including an exterior surface and an inner surface, the inner surface defining a second internal conduit extending along a second longitudinal axis, the first tubular member received in the internal conduit such that the first longitudinal axis is axially aligned with the second longitudinal axis, the inner surface including a sealing surface portion circumscribed about the second longitudinal axis and a groove between the sealing surface portion and the second end;
• a retainer ring disposed in the groove;
• and
• a gripper ring disposed along the inner surface of the second tubular member and in contact with the external helical surface of the first tubular member, the retainer ring between the gripper ring and the second end.