Passivation of carbon steel using encapsulated oxygen
CA 2109366 C · Owner: The Babcock & Wilcox Company · Inventors: Paul, Larry D.; Martin, Donald T.; Carpenter, Neil N.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A protective passive oxide layer is formed on the inner surfaces of metal heat pipes or tubes including their end caps, welds and accompanying hardware through the use of an oxygen encapsulation method. After cleaning the tube and its accompanying parts the tube, is reassembled and existing gases within the tube are removed thereby creating a vacuum inside the tube. The tube is then filled with pure oxygen and sealed. After the oxygen is sealed within the tube, the sealed tube is heated thereby forming a passive oxide layer such as, magnetite (Fe3O4) on the inner surface of the tube.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed October 27, 1993 and granted June 16, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 27, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 27, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.