US PATENT SUBCLASS 137 / 515.5
.~.~.~ Valve seat formed on or carried by a coupling element

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use


137 /   HD   FLUID HANDLING

455  DF  LINE CONDITION CHANGE RESPONSIVE VALVES {11}
511  DF  .~ Direct response valves (i.e., check valve type) {14}
515  DF  .~.~ In couplings for coaxial conduits, e.g., drill pipe check valves {3}
515.5.~.~.~ Valve seat formed on or carried by a coupling element

DEFINITION

Classification: 137/515.5

(under subclass 515) Devices in which the valve seat element is formed as an integral part of one of the coupling elements or is separate but carried by one of the coupling elements.