Method and apparatus for counting turns when making threaded joints
US4176436A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1978 |
| Grant date | Dec 4, 1979 |
| Priority date | — |
| Expiry date | Sep 12, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/53687
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus are disclosed for making threaded joints, such as pipe joints, within a range of predetermined applied torque and turns values. A pipe or a pipe and a coupling are threaded onto the end of a pipe string. The applied torque is monitored and, when a reference torque value is exceeded, the number of turns are counted. When either the actual torque or the actual turns exceeds a predetermined minimum value for that parameter and the value of the other parameter exceeds a predetermined minimum value, but is less than a predetermined maximum value, a good joint is indicated and the make-up is stopped. A bad joint is predicted and make-up is stopped when the value of the actual torque divided by the actual turns falls outside a range of values defined by the slopes of a pair of boundary lines and predetermined minimum torque and minimum turn values. The actual turns value is a count which is initiated the first time the actual torque value equals the reference torque value, the count being incremented when the actual torque value is greater than the reference torque value and being decremented when the actual torque value is less than the reference torque value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.