Patents Examined by James A. Leppin
  • Patent number: 4294315
    Abstract: A landing nipple, adaptable to be made up in a tubing string having a sliding sleeve disposed in its bore for selectively providing communication of balance and control pressure fluid to the nipple bore. When the sleeve is shifted to its first, upper position, balance fluid is conducted via the nipple to a tubing retrievable safety valve placed in the tubing string below the nipple. In the event the tubing retrievable safety valve is taken out of service, a secondary safety valve can be landed in the nipple, the sleeve shifted to its downward, second position, opening sleeve ports for conducting control and balance fluids to the landed, secondary safety valve.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: October 13, 1981
    Assignee: Otis Engineering Corporation
    Inventors: John H. Yonker, Ernest P. Fisher, Jr., David Bills