Sucker rod coupling with protective coating
US4905760A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 12, 1989 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Jan 12, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T403/5746
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A standard size, steel oil well sucker rod coupling is machined to decrease its external diameter, producing a constant diameter along its length. Then, the coupling is machined to produce chamfers or bevels around the circumference on the ends, such that the diameter at the radial faces is less than at the body of the coupling. Next, abrasive blast-cleaning of the coupling produces a uniform, angular, anchor profile along the machined areas on the exterior of the coupling. Finally, a specially selected, fusion bonded, resinous coating is applied to the exposed surface. The radial faces may or may not be coated. The unique protective coatings impart abrasion resistance in a pumping oil well and serve as an electrical barrier to preclude electrochemical, corrosive, attack of the mild steel coupling core. Extended service life of the coupling is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.