Threaded joint for steel pipes
US8409718B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 15, 2010 |
| Grant date | Apr 2, 2013 |
| Priority date | — |
| Expiry date | Jan 20, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A threaded joint for steel pipes for use in an oil well which has galling resistance and which is protected from rusting comprises a pin and a box each having a contact surface including a threaded portion and an unthreaded metal contact portion. The contact surface of at least one of the pin and the box has a lower layer of a viscous liquid or semisolid lubricating coating comprising at least wax and a fatty acid alkaline earth metal salt and not containing a harmful heavy metal such as lead and an upper layer of a dry solid coating formed from an aqueous resin coating composition, an organic solvent type coating composition, or an ultraviolet curing coating composition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.