4B Absa Exam Questions

Question 1

Machine bolts are commonly supplied with

Answer 1

Hexagon heads

Question 2

Which is not found on the low side of an ammonia absorption refrigeration system

Answer 2

Generator

Question 3

Bacteria can range from _______ in size

Answer 3

0.2 to 5 microns

Question 4

A light fuel oil flame should

Answer 4

Be bright yellow, with orange at the tips of the flame

Question 5

Soot should be removed from fire tube boiler tubes with

Answer 5

Wire brushes

Question 6

The most widely used refrigerant metering device, which consists of a pressure-sensitive Bellows or diaphragm connected to a temperature sensing bulb, is the

Answer 6

Thermostatic expansion valve

Question 7

For economic operation, the steam Supply to a steam engine is cut off once the Piston has travelled _______ of its stroke

Answer 7

1/4 to 1/3

Question 8

ASME VII states that a high pressure steam plant comprised of a single power boiler may have it’s boiler and steam lines

Answer 8

Warmed up at the same time, or independent of each other

Question 9

The instrument that measures the viscosity of an oil at a certain temperature as it flows through a small diameter tube, is called

Answer 9

A saybolt viscometer

Question 10

The propeller axial-flow fan;

Answer 10

Find application in unit heaters, air-cooled condensers, and as an exhaust fan for ventilation purposes

Question 11

Gas turbines are ideal where

Answer 11

Water is scarce

Question 12

Natural draft cooling towers are divided into;

2

Answer 12

Atmospheric towers and chimney Towers

Question 13

The most commonly used acid for boiler cleaning is

Answer 13

Hydrochloric acid

Question 14

Occupancy sensors;

Answer 14

Are automatic switches

Question 15

The raw natural gas from the wells, for use in a gas processing plant, is known as

Answer 15

Feedstock

Question 16

The set pressure of a safety valve may only be adjusted by

Answer 16

The safety valve manufacturer, it’s authorized representative, or an assembler

Question 17

Galvanic corrosion depends on

Answer 17

A difference in electrochemical potential between dissimilar metals

Question 18

The output power of a gas turbine depends on

Answer 18

The mass of hot gas passing through the turbine per unit time

Question 19

An essential auxiliary in a gas turbine installation is

Answer 19

A starting motor

Question 20

The total or methyl alkalinity test indicates the alkalinity that is due to

Answer 20

All forms of alkalinity

Question 21

Rotary pumps

Answer 21

Are positive displacement pumps

Question 22

Which of the following has the greatest effect on the viscosity of lubrication oil

Answer 22

Temperature

Question 23

If an oil must flow at a very low temperature, it must have the following additive

Answer 23

Pour Point depressant

Question 24

In a circulating domestic hot water system, automatic air vents

Answer 24

Remove air that is released when water is heated

Question 25

Infrared heaters are commonly installed to direct their heat output towards

Answer 25

Floors

Question 26

It is good design practice to select a steam coil size so that

Answer 26

At least 40% of the coil capacity is needed when the air temperature entering the coil is -1°C

Question 27

The kind of Grease used for heavily loaded Machinery operating at slow speeds is the

Answer 27

Specialty Grease

Question 28

If a shutdown occurs during normal firing of a boiler and the steam pressure is below the normal cut out value, the problem could be

Answer 28

An interlock, such as the combustion air proving switch has failed

Question 29

A deep seal Plumbing trap has a water seal depth of

Answer 29

10cm

Question 30

The first step when repairing a faucet

Answer 30

Shut off the water at the nearest isolation valve

Question 31

In an internally fired, gas-fired infrared heater, the surface temperature is about

Answer 31

400°C

Question 32

A normal anti-friction bearing temperature operating range is

Answer 32

65 to 70°C

Question 33

When the maximum building demand for potable water is always less than the maximum flow available from a municipal or local distribution system, which system can be used

Answer 33

Tankless constant pressure system

Question 34

The final step when replacing a firetube

Answer 34

Hydrostatic test

Question 35

The heat recovery system that uses a sealed tube, capillary Wick structure, and a refrigerant liquid, is called

Answer 35

Heat pipe

Question 36

One of the ways to detect a fault in a reciprocating steam engine is by;

Answer 36

Monitoring changes in its sound

Question 37

Which is not a type of centrifugal fan

Answer 37

Radial blade fan

Question 38

Ladders that are used in the workplace should comply with

Answer 38

WCB regulations and CSA standards

Question 39

In a circulating domestic hot water system, automatic air vents

Answer 39

Remove air that is released when water is heated

Question 40

The _______ number of oil indicates the acidity of oil

Answer 40

Neutralization

Question 41

A closed cycle gas turbine

Answer 41

Recycles the same working fluid

Question 42

The characteristics of a grease are determined by

Answer 42

It’s thickening agent or soap

Question 43

Most dimmer switches sold today

Answer 43

Are solid state devices

Question 44

Smaller spark ignition engines use _______ to vaporize gasoline

Answer 44

Carburetors

Question 45

A cold weather cooling tower bypass valve should not be fully closed until the temperature reaches

Answer 45

About 27°C

Question 46

The combustion chamber of a gas turbine

Answer 46

Is where fuel is added to Air, and burned

Question 47

If ambient air temperatures are very low, the preferred lubricant is a

Answer 47

Solid lubricant