Screw joint for oil well pipe
CA 2395943 A1 · Owner: Vallourec Mannesmann Oil & Gas France · Inventors: Maeda, Jun; Tsujimura, Takuya; Nagasaku, Shigeo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A screw joint having a box part and a pin part used for screw-tightening oil well pipes which prevents a stress acting on the outer surface of the box part from exceeding the yield strength of a joint base metal so that stress corrosion does not occur on a joint part wherein a thread interference amount , T is controlled to be under a specified value calculated as a function of the inner diameter D1 of the pin part, thread pitch diameter D2 at a basic diameter position, outer diameter D3 of the box part inner load pressure Pi, yield strength of base metal .sigma.y and Young's modulus E, whereby the , screw joint suitable to use for tightening oil well pipes can be provided.
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 December 27, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 27, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 2021.
- 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.