Patents Assigned to Vallourec, S. A.
  • Cylindro-conical pipe joint
    Patent number: 4398756
    Abstract: Separable joint for oil well pipe in which both the male and female members have a cylindrical threaded section adjacent a frusto-conical thread section, and the female member has an internal shoulder against which the end of the male member seals.
    Type: Grant
    Filed: November 13, 1981
    Date of Patent: August 16, 1983
    Assignee: Vallourec, S. A.
    Inventors: Jean Duret, Charles Soulier, Georges Trouillet