US PATENT SUBCLASS 251 / 157
WITH MEANS TO INCREASE HEAD AND SEAT CONTACT PRESSURE

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

Internet Version by PATENTEC © 1999      Terms of Use


251 /   HD   VALVES AND VALVE ACTUATION

157WITH MEANS TO INCREASE HEAD AND SEAT CONTACT PRESSURE {8}
158  DF  .~> With positive reduction {3}
170  DF  .~> Seat pressed to valve {3}
175  DF  .~> Fluid pressure
176  DF  .~> Spring {3}
187  DF  .~> Separate actuators or actuator motion {2}
190  DF  .~> Piston {1}
192  DF  .~> Rotary valve
193  DF  .~> Gate valve {3}

DEFINITION

Classification: 251/157

(under the class definition) Devices which have means other than that which actuates or biases to valve open or closed position, to increase the contact pressure between valve and seat.

SEE OR SEARCH THIS CLASS, SUBCLASS:

56, for fluid actuated plural operations including means to increase the head and seat contact pressure.

SEE OR SEARCH CLASS

137, Fluid Handling,

246.2, for this means combined with means for liquid sealing at the valve interface.