Patent · US Expired

Process for thermal treatment of tubes

US4252578A · kind A · utility

4Cited by
3References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 9, 1979
Grant dateFeb 24, 1981
Priority date
Expiry dateFeb 9, 1999

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S148/909
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

Elongated steel tubes are grouped together and bound into bundles with bing sufficiently tight that there is no clearance or play between the tubes during heat treatment. Such binding provides a rigid mechanical assembly which prevents any lateral deformation of the tubes with respect to each other. Heat treatment is carried out while the tubes are tightly bound in bundles, and each bundle is supported in the furnace at least at several locations along its length to prevent deformation. The bundles are preferably of hexagon shape in section but can be of other geometric shapes. This technique results in heat treated tubes which are perfectly straight.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.