LNG-75 Spider

The spider is made in an all-metal casing with a wellhead connector and tubing passage. Overlap of the connector is carried out by a door, which is mounted to the body on fingers with a chain. A conical hole is provided in the product body and door, and a reciprocal cone is located in the wedge block. The wedge block is presented in four sections. Each of them is filled with removable spider liners, which are secured by locking cotter pins and quick-detachable pins. The wedge block is suspended using lifting levers.

The rotation of the two spider shafts is carried out in plain bearings, which are pressed into the housing brackets. The sling on the necks of the shafts, connected with the cylinder, ensures synchronization of their movement. The latch limits the movement of the cylinder and ensures the fixation of the wedge block in the open state. The amplitude of movement of the cylinder rod reveals the pharynx capture by an amount sufficient for the passage of the tubing coupling. When liquid or air enters the cylinder cavity, the rod moves, shifting the sling, which leads to the simultaneous rotation of both shafts with lifting arms. When the wedge block is lowered and the wedges are closed, the tubing is captured. The friction force under the influence of the mass of the pipes is the retention of the tubing by the teeth of the liners, the inclination vector of which is opposite to the influence of the gravity of the tubing. When the cylinder lifts the wedge block, the grip opens, the tubing is released.

The reliability of the mechanism is largely due to the use of the cast-iron spider housing SPG-75. Parts that take on high loads undergo heat treatment during the production of the mechanism. Parts, the operation of which involves high intensity, in order to increase wear resistance are processed by conducting high-frequency currents through them.