Insulation True and False

Question 1

The ultimate cost of insulation should be the only design consideration factor.`

Answer 1

false

Question 2

A good-quality vapor barrier is guaranteed to exclude water vapor entirely.

Answer 2

false

Question 3

Most thermal insulating materials have a higher thermal expansion coefficient than metals.

Answer 3

false

Question 4

The provision of air spaces for thermal insulation purposes is recommended.

Answer 4

false

Question 5

When fluids are static in pipes or vessels and the ambient temperate is below the freezing point of the contained fluid, there is no way to prevent freezing.

Answer 5

false

Question 6

If a cold surface is at a temperature lower than the freezing point, moisture will freeze and tend to rupture and break away the insulation.

Answer 6

true

Question 7

An increase in the amount of insulation applied will raise the rate of heat loss through the insulation and raise the total cost during the life of the product.

Answer 7

false

Question 8

The required life of the insulation system shall be considered because this affects the annual cost and hence the economic thickness.

Answer 8

true

Question 9

Aerogels pose no chemical threat to the environment.

Answer 9

true

Question 10

Dense brick has a relatively low conductivity.

Answer 10

false

Question 11

The manufacturer’s declared value of thermal conductivity is only appropriate to the temperature of use.

Answer 11

false

Question 12

If conservation of heat or power is the deciding factor, the cost savings per year is the most important factor, compared to installed cost.

Answer 12

true

Question 13

The ability of air to hold water in the vapor phase is reduced as the temperature decreases.

Answer 13

true

Question 14

The main advantage of molded insulation is the ease of application and replacement when undertaking repairs for damaged lagging.

Answer 14

true

Question 15

Loosefill material and unbonded mattresses are liable to compact under the influence of vibration and thermal cycling.

Answer 15

true

Question 16

Goals in thermal science are to minimize capital and operation costs as well as heat loss.

Answer 16

true

Question 17

For any given heat loss, a material of low thermal conductivity will be thicker than an alternative material of high conductivity.

Answer 17

false

Question 18

Low bulk density is normally associated with low thermal conductivity in the low and medium temperature ranges.

Answer 18

true

Question 19

Thinner layers of insulation increase the surface area emitting heat and also increase the outer surface that will require protection.

Answer 19

false

Question 20

Difficult or unusual site conditions will influence the selection or application of insulating materials.

Answer 20

true

Question 21

Internal condensation and ice formation will appreciably increase the effectiveness of the thermal insulating material.

Answer 21

false

Question 22

The main purpose of insulation is to limit the transfer of energy between the inside and outside of a system.

Answer 22

true

Question 23

Aerogels have the highest thermal conductivity of any material used for cryogenic service.

Answer 23

false

Question 24

Thinness creates more space in and around pipe racks and equipment.

Answer 24

true

Question 25

Due to the difference in expansion coefficients of metals and insulating materials, it is necessary to make allowance for the differential movements between the hot surface, the insulant, and the finish.

Answer 25

true

Question 26

Before any stripping work is carried out, it is necessary to determine what type of insulating material is involved.

Answer 26

true

Question 27

Insulation materials can be classified into organic and inorganic types.

Answer 27

true

Question 28

An air space is much more effective for thermal insulation purposes than a space of similar dimensions filled with one of the convectional insulating materials.

Answer 28

false

Question 29

Epoxy and polyester resins give good resistance against mechanical damage, together with protection against the weather and against chemical spillage.

Answer 29

true

Question 30

Care needs to be taken to ensure that vapor barrier does not add seriously to the fire hazard of a complete system.

Answer 30

true

Question 31

Low-temperature insulators are used in low-temperature heating and steam equipment, steam lines, flue ducts, etc.

Answer 31

false

Question 32

Aerogel insulation systems will not break during shipment.

Answer 32

true

Question 33

Normally, the theoretical heat loss will be based on the manufacturer’s declared value of thermal conductivity and, unless otherwise stated, it will refer to conditions of ambient still air at 20° C (68° F).

Answer 33

true

Question 34

Thermal conductivity is always specified at real-time temperature of the insulation material.

Answer 34

false

Question 35

There are two basic types of monolithic lining: castable refractory and plastic refractory.

Answer 35

true

Question 36

For materials to be used at elevated temperatures, it will be necessary to consider the many factors that may result in deterioration under conditions of service.

Answer 36

true

Question 37

Dense refractory brick is required in most furnaces to withstand the high internal temperature.

Answer 37

true

Question 38

A thermal insulator is a poor conductor of heat and has a high thermal conductivity.

Answer 38

false

Question 39

The difference between mouldable (moldable) and rammable material is that the latter is a stiffer mix, making it more self-supporting.

Answer 39

true

Question 40

Thermal insulation may be applied for protection of personnel from injury through contact with equipment.

Answer 40

true

Question 41

Aerogels are lighter than other insulation materials.

Answer 41

true

Question 42

The required thickness of insulation for any specific application depends on the characteristics of insulating material as well as the purpose of the equipment.

Answer 42

true

Question 43

The thermal conductivity of most insulating materials varies only with temperature.

Answer 43

false

Question 44

As a general rule, a vapor barrier will be required over the insulation on all plant working at temperatures below the relevant “ dew point” of the ambient air.

Answer 44

true

Question 45

Technical requirements should take precedence over economic considerations when the insulating material is required to avoid danger to personnel.

Answer 45

true

Question 46

The thermal conductivity of materials decreases with temperature.

Answer 46

false

Question 47

Asbestos or any product containing asbestos materials shall be applied by means of a spray process.

Answer 47

false

Question 48

Thermocol is mainly used as cold insulation for piping and cold storage construction.

Answer 48

true

Question 49

It is acceptable for insulation to interfere with the operation of expansion joints.

Answer 49

false

Question 50

Before vapor barrier is applied, the insulant shall be smooth and regular with all joints tightly butted together so that there are no gaps.

Answer 50

true

Question 51

The effectiveness of vapor barrier is expressed in terms of the rate at which water vapor is transmitted through it under defined conditions.

Answer 51

true

Question 52

When the technical requirements of the application have been met, the total cost (distinct from the initial cost) during the life of the installation is the prime consideration.

Answer 52

true

Question 53

When a plaster-type finish is applied, an expansion joint shall be provided by cutting at a circumferential joint in a single layer or in the outer layer of a double-layer system.

Answer 53

true

Question 54

A high thermal conductivity is desirable to achieve a maximum resistance to heat transfer.

Answer 54

false

Question 55

Requirements for the preparation of surfaces need to be clearly stated.

Answer 55

true

Question 56

On tanks and vessels, preformed slabs or mattresses may be used on hot service, but on cold duties, slabs are normally used.

Answer 56

true

Question 57

For very low temperatures, the use of multiple vapor barriers may be justified.

Answer 57

true

Question 58

At the junction between preformed insulating materials and fixed steel work, the joint area shall be packed with mineral fiber to accommodate differential thermal movement.

Answer 58

true

Question 59

Expansion joints need to be provided in furnace refractories at regular intervals to avoid overstressing the bricks at elevated temperature.

Answer 59

true

Question 60

Insulation prevents condensation on cold surfaces and the resulting corrosion.

Answer 60

true

Question 61

The thermal expansion coefficients of plastic pipe are generally much lower than those of metals.

Answer 61

false

Question 62

All thermal insulating materials in common use are nonflammable.

Answer 62

false

Question 63

Aerogels offer poor resistance to flame spread and smoke emission.

Answer 63

false

Question 64

Aerogels are extremely hydrophobic and therefore have outstanding resistance to moisture.

Answer 64

true

Question 65

Pipes of small diameter have relatively high surface temperatures and low rates of heat loss.

Answer 65

false

Question 66

Insulation can be classified into three groups according to the temperature ranges for which they are used: low-temperature insulation (up to 90° C; 194° F); medium-temperature insulation (90-325° C; 195-620° F); high-temperature insulation (325° C [620° F] and above).

Answer 66

true

Question 67

Inorganic insulations are based on hydrocarbon polymers, which can be expanded to obtain high void structures.

Answer 67

false

Question 68

All refractory must be heated quickly from cold owing to the need to minimize the stresses created by differential thermal expansion.

Answer 68

false

Question 69

Insulation is recommended for steam, condensate, heating, and hotwater supply mains, in order to conserve heat and avoid high ambient temperatures.

Answer 69

true

Question 70

Air flow over an outer surface will tend to reduce the surface temperature and increase the rate of heat loss.

Answer 70

true