The internal hydraulic centralizer is designed for centering the ends of individual pipes and sections during the assembly of fixed and rotary joints during the construction of pipelines. It is used where the use of external centralizers is impossible. Allows you to continuously weld and use welding machines. The mechanism for spreading the inner guides, leveling the pipe joint, is a hydraulic cylinder. The pressure created on the inner wall of the pipes is transmitted from the operator using a hand drive. Used where it is not possible to use an air or hydraulic power source.