Abstract: The present disclosure discloses a pressure-retaining cap screwing and unscrewing device for a marine natural gas hydrate pressure-retaining rock-core barrel, wherein it comprises a cap-unscrewing chuck, a support cylinder, a pressure-retaining cap screwing and unscrewing head, a spring, a screwing and unscrewing shaft, and a pressure-retaining cap screwing and unscrewing sleeve, a reducer and a motor; an input shaft of the reducer is connected to the motor, an output shaft of the reducer is the screwing and unscrewing shaft which is a tubular structure with a plurality of guide holes provided on a side wall thereof. The device is simple in structure, compact, light in weight, and convenient to control, and the pressure-retaining cap can be discarded.

Abstract: Embodiments of the invention generally relate to a tubular handling tool. The tool may include a base and a ring or sleeve member. The tool may further include an actuation member configured to move or rotate the ring or sleeve member relative to the base. Additionally, the tool may include a clamp or dog member attached to the base. The clamp or dog member is configured to move between a radially retracted position and a radially extended position as the ring or sleeve member moves or rotates relative to the base.