Basic Instrumentation Ch 10

Question 1

A flow bean, or choke, provides fixed flow control?

a) true
b) false

Answer 1

a) true

Question 2

A flow bean has what type of opening?

Answer 2

Both

Question 3

Mechanical measuring devices installed with orifice plates use feedback mechanism to produce a force balance

a) true
b) false

Answer 3

a) true

Question 4

Electronic differential-pressure transmitters are the most popular means of measuring flow

a) true
b) false

Answer 4

a) true

Question 5

The electrical analog output of the PLC is, like transmitter’s output, what?

Answer 5

4 to 20 mA

Question 6

In the equation for flow Q = K (Pd) ^ 1/2

What is the flow coefficient?

Answer 6

K

Question 7

In application where a throttling valve requires control, it uses four different systems to do this:

Answer 7

1) measure the differential pressure
2) converts it to a flow signal
3) compares signal against desired set point
4) produces a signal to control valve

Question 8

Equipment that incorporates all the features in a single enclosure is a ____

Answer 8

flow controller

Question 9

In controlling gas flow, both the ____ and ____ are located in the line in which flow is to be controlled

Answer 9

control valve ; primary element

Question 10

A throttling valve should not be installed in a positive displacement pumps discharge line because

Answer 10

excessive line pressure could build up against a closed valve

should it close, it is possible to over-pressurize the line and pump

Question 11

Pressure and flow are also used to adjust the set point of flow controllers

a) true
b) false

Answer 11

b) false