THREADED JOINT WITH DRY LUBRICATING COATING Russian patent published in 2018 - IPC F16L15/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to threaded connections for steel pipes used in the oil industry. Threaded connection with a dry lubricating coating consists of mating elements with external and internal threads, having a common surface contour. Mating threaded surface of the element with an external thread has an anti-corrosion UV curable single-layer coating. Coating on the mating threaded surface of the element with a female thread is a single-layer antifriction single layer applied to the entire surface of the thread and contains a binder based on polyurethane, isocyanate hardener and fillers, which form a lubricating film in the surface layer of the coating during curing, which increases the antifriction and sealing properties of the coating. Anti-friction coating contains as a binder from 25 wt. % to 35 wt. % mixture of polyols, as a hardener from 10 wt. % to 50 wt. % isocyanate, as fillers from 10 wt. % to 65 wt. % antifriction additives, additionally contains up to 8 wt. % dispersion of paraffin, may contain up to 3 wt. % corrosion inhibitor, up to 10 wt. % zinc powder, up to 2.5% by weight of phosphoric acid esters. Thickness of anti-corrosion and anti-friction coatings is 10–110 microns.

EFFECT: threaded joint with a dry lubricating coating has high anti-corrosion properties, resistance to abrasion under the influence of significant loads, and also provides tightness.

5 cl, 2 tbl