Module 6 Flashcards Preview

MT 108 Chapter 4 > Module 6 > Flashcards

Flashcards in Module 6 Deck (31):
1

a valve used in a pneumatic system to direct the airflow from one place to another to permit the actuating parts to perform their work

Control valve

2

the lowest pressure that will open a valve

Cracking pressure

3

a valve having three primary connections on the outside of the valve body, and three ports inside the valve

Three-way valve

4

a valve with four primary connections and either four or five external ports

Four-way valve

5

a special four-way valve with five external connections, all connected to primary system connections

Five-way valve

6

Name the four methods of identifying control valves.

Number of primary connecting ports
Number of control positions
Type of control element
Method of operation

7

If not properly sized, globe valves can cause _____ flow.

Turbulent

8

A gate valve should not be used for _____ flow.

Throttling or Regulating

9

Needle valves used for regulating flow have high _____ losses.

Pressure

10

The most common method of controlling automatically operated valves is with electric _____.

Solenoids

11

Two-position automatically operated valves are classified as being normally _____ or normally _____.

Open, Closed

12

Large quantities of high pressure air are best controlled by solenoid valves that are _____-operated.

Pilot

13

Check valves are classified as automatic two-way, two-_____ valves.

Position

14

A disadvantage of two-way spool valves is that they are not always _____.

Pressure Balanced

15

Three-way valves have three _____ or working connections.

Primary

16

The most common application of a two-position, three-way valve is in _____ control.

Directional

17

Three-way valves having a blocked center position are usually made to center _____.

Automatically

18

When compressed air completes its work it is usually _____ to the atmosphere.

Exhausted or Vented

19

Four-way valves reduce the total number of _____ in a system.

Controls

20

Airflow in a nonactuated two-position, four-way valve flows in _____ direction(s).

Two

21

The centering of a three-position, four-way valve is usually accomplished by _____.

Springs

22

A manually operated flow control valve may be further identified by all of the following except
a. number of connecting ports
b. number of control positions
c. pressure capacity
d. type of control element

c. Pressure capacity.

23

The lowest pressure that will open a check valve is called the _____ pressure.

Cracking

24

Manually operated stop or isolating valves (globe, gate, or ball) are classed as _____-way valves.

Two

25

A three-way valve is constructed with three _____.

Primary connections

26

The high-pressure losses in a needle valve are caused by the _____.

Valve seat

27

Three-position, three-way valves are usually held in the center position by _____.

Springs

28

What is the most common method of actuating automatically operated flow control valves?

Electric solenoids

29

Compressed air returning through a valve after it has done work is often directed to the _____.

Atmosphere

30

Because a solenoid has limited lifting strength, the valve closing spring in a high-pressure system must be _____ and the valve seat opening _____.

Weak; small

31

In how many directions can air flow in a nonactuated two-position, four-way valve?

Two