Rotary-Shaft Control Valve

Question 1

Arm attached to rotary valve shaft to convert linear actuator stem motion to rotary force to position disk or ball of rotary-shaft valve

Answer 1

Actuator Lever

Question 2

The flow-controlling member of rotary-shaft control valves using a complete sphere with a flow passage through it. The flow passage equals or matches the pipe diameter

Answer 2

Ball Full

Question 3

The flow-controlling member of rotary shaft control valves using a partial sphere with a flow passage through it.

Answer 3

Ball Segmented

Question 4

a polished or plated partial-sphere surface that rotates against the seal ring throughout the travel range with a V notch shape

Answer 4

Ball V-notch

Question 5

The calibration of the actuator spring range of a control valve to account for the in-service process forces

Answer 5

Bench Set

Question 6

An actuator in which power is supplied in either direction

Answer 6

Double-Acting Actuator

Question 7

A condition wherein the valve closure member moves to a closed position when the actuating energy source fails

Answer 7

Fail-Closed

Question 8

A condition wherein the valve closure member moves to an open position when the actuating energy source fails

Answer 8

Fail-Open

Question 9

A characteristic of a valve and its actuator, which upon loss of actuating energy supply, will cause a valve closure member to be fully closed, fully open, or remain in the last position, whichever position is defined as necessary to protect the process

Answer 9

Fail-Safe

Question 10

Relationship between flow through the valve and percent rated travel as the latter is varied from 0 to 100 percent. Designated as either inherent or installed

Answer 10

Flow Characteristic

Question 11

A constant related to the geometry of a valve, for a given travel, that can be used to establish flow capacity

Answer 11

Flow Coefficient

Question 12

An undesirable oscillation of appreciable magnitude, prolonged after external stimuli disappear. Sometimes called cycling or limit cycle

Answer 12

Hunting

Question 13

This is the fluid ,generally air or gas, used to supply the power for operation of valve positioner

Answer 13

Operating Medium

Question 14

Action in which two or more signals are generated or two or more final controlling elements are actuated by an input signal, each one responding consecutively, with or without overlap, to the magnitude of that input signal

Answer 14

Split Range