Process for straightening a tube
US7654122B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 2008 |
| Grant date | Feb 2, 2010 |
| Priority date | — |
| Expiry date | Oct 8, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In straightening a tube using a roll straightening machine provided with drum type straightening roll pairs vertically opposingly disposed, at least an outer layer portion of a roll main body is made of elastic material having spring type hardness Hs (JIS K 6301 A type) of 50 to 100 in at least three pairs of straightening rolls on an outlet side of the roll straightening machine, and an offset amount is imparted to a tube engaged in the three pairs, at least, of straightening opposing rolls such that η defined by an equation (1) ranges from 1.0×10−3 to 1.5×10−3. The offset amount is set at three positions along a tube axis where the upper and lower rolls of each pair horizontally cross. Therefore, an S/N ratio can be enhanced in an eddy current test from inside of the tube to improve inspection efficiency, and excellent quality accuracy can be ensured in a heat transfer tube used in a steam generator and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.