METHOD FOR ASSEMBLY OF TIGHT THREADED JOINT Russian patent published in 2009 - IPC F16L15/00 

FIELD: technological processes.

SUBSTANCE: invention is related to threaded joints. Hydrostatic fluid drive is used to screw and tighten threaded joint of parts, in one of which internal thread is arranged, while in the other one - external conic thread. Screwing is started at stabilised idle run pressure in hydraulic actuator of hydrostatic fluid drive that rotates one of screwed parts, and tightening is completed after specified pressure is obtained in hydraulic actuator, i.e. after pump, hydraulic actuator and reduction gear inertia has been overcome, and their reaching stabilised mode of rotation. Quality of assembly is estimated by character of pressure variation in hydraulic actuator depending on angle α of rotary part turn; tightening value of contact force is assumed to be achieved in case pressure increase in hydraulic actuator in process of tightening happens in specified limits continuously and synchronously with turn by preset angle. Pressure increase in hydraulic actuator is limited with the help of direct-acting overflow valve, actuation of which stops changing of angle α of rotary part turn at appropriate pressure value in hydraulic actuator.

EFFECT: invention provides for accuracy of joint monitoring and reliability.

4 cl, 2 dwg, 4 tbl