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Expired Canadian patentCanada

Flow control apparatus and method

CA 1202863 A · Owner: Marathon Oil Company · Inventors: Luetzelschwab, Wayne E.

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Apparatus, and method, for controlling the flow of dilute solutions of polymers such as dilute aqueous solutions of partially hydrolyzed polyacrylamides without causing any significant degradation of the polymer comprising the solutions. In one embodiment, the apparatus comprises a needle valve positioned in a conduit for transporting polymer solutions, and across which a fluid pressure differential exists. In another embodiment the, apparatus comprises a self-adjusting flow regulator which incorporates a tapered, or pointed throttle, carried on a reciprocatable piston.

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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

  • Granted April 8, 1986. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 8, 2003.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 21, 1983
GrantedApril 8, 1986
Term endedApril 8, 2003
Patent numberCA 1202863 A
Classification (IPC)E21B43/22 +2 more

Timeline

Timeline From CIPO dates

1984198619881990199219941996199820002002Application filedMarch 21, 1983Patent grantedApril 8, 1986Term endedApril 8, 2003

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.