Patents by Inventor Darrell C. Crain

Darrell C. Crain has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Gate valve
    Patent number: 5878994
    Abstract: A gate valve having a bolted bonnet is modified by welding a first ring to the valve bonnet and a second identical ring to the valve housing with weld beads on the inner edge of the rings. After mating the bonnet and the housing, a final weld is made joining the outer edges of the two rings.
    Type: Grant
    Filed: December 1, 1995
    Date of Patent: March 9, 1999
    Assignee: Phillips Petroleum Company
    Inventor: Darrell C. Crain