US PATENT SUBCLASS 137 / 630
.~.~.~ One valve seats against other valve (e.g., concentric valves)

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

561 R  DF  SYSTEMS {32}
628  DF  .~ Sequentially progressive opening or closing of plural valves {4}
629  DF  .~.~ Pressure equalizing or auxiliary shunt flow {1}
630.~.~.~ One valve seats against other valve (e.g., concentric valves) {5}
630.11  DF  .~.~.~.~> Locomotive throttle
630.12  DF  .~.~.~.~> Gate
630.13  DF  .~.~.~.~> With balancing chamber
630.14  DF  .~.~.~.~> First valve moves second valve
630.15  DF  .~.~.~.~> Actuator moves both valves

DEFINITION

Classification: 137/630

(under subclass 629) Subject matter in which one valve is arranged to control a passage through the other valve element.

(1) Note. The valves are frequently arranged so that they are concentric and the smaller valve, which is the first to open, seats against the larger valve.

(2) Note. Frequently, the initially opened supplemental valve is mounted on and seats against the main valve and is termed a "pilot" valve although no servo-motor action is present because the supplemental valve merely tends to partly equalize the pressures on opposite sides of the main valve so that the main valve may be opened more easily against line pressure.

SEE OR SEARCH THIS CLASS, SUBCLASS:

630.21, and 637.5, for other concentric valves.

SEE OR SEARCH CLASS 251, Valves and Valve Actuation,

38+, for fluid actuated or retarded valves in which a pilot valve is seated on the motor or valve element.