INSULATION

Benefits of Insulation
Insulation Materials
Effects of Insulation Thickness on Equipment Piping

Benefits of Insulation

Conserves energy by reducing Heat loss or gain
Properly designed and installed insulation systems immediately reduce the need for energy.
Controls surface temperatures for personnel Protection and Comfort
Insulation reduces the surface temperature of piping or equipment to a safer level, resulting in increased worker safety.
Facilitates process temperature control
By reducing heat loss or gain, insulation can help to maintain the process temperature to a pre-determined value.
Prevents Condensation on Cold Surfaces
Sufficient Insulation thickness with a good vapor retarder is the most effective means of controlling condensation and limiting corrosion on cold piping, ducts, chillers and roof drains.
Prevents or reduces damage to Equipment from exposure to Fire or Corrosive Atmospheres
When used in combination with other materials, fiber glass and rock and slag wool insulation help provide fire protection, grease and air-duct fireproofing and electrical protection.
Controls Noise
Insulation materials can be used to form a sound barrier between the source and the surrounding area.
A wide range of insulation materials is available; however, few meet the requirements of modern construction.
Selection of insulation material should be based on initial cost, effectiveness, durability, the adaptation of its form/shape to that of the component and the installation methods available in each particular area.
From an economic point of view, it may be better to choose an insulating material with a lower thermal conductivity rather than increase the thickness of the insulation in the hold walls.

R-Value

The R-value can be defined as the resistance that any specific material offers to the heat flow.
A good insulation material should have a high R-value.
R-value increases with increase in thickness of the insulation material.
R-Value = x/l x → Insulation thickness l → Length of Material

Classification of Insulation Materials

Low Temperature Thermal Insulation
15.6°C through 0°C (60°F through 32°F) i.e. Cold or chilled water.
-0.6°C through -73.9°C (31°F through -100°F) i.e. Refrigeration.
-73.9°C through -267.8°C (-101°F through -450°F) i.e. cryogenic.

Intermediate Temperature Thermal Insulation

16.1°C through 99.4°C (61°F through 211°F) i.e. Hot water and steam condensate.
100.0°C through 315.6°C (212°F through 600°F) i.e. Steam, high temperature hot water.
High Temperature Thermal Insulation
815.6°C through 1316.1°C (601°F through 1500°F) i.e. Turbines, breechings, stacks, exhausts, incinerators, boilers.

Insulation Materials

Asbestos
Fiber glass
Mineral Wool
Elastomers
Foam insulations

ASBESTOS

Asbestos is a mineral fiber that has been used commonly in a variety of building construction materials for insulation and as fire-retardant.
Asbestos was commonly used before 1970 in building products because it was fireproof, a good thermal insulator, and easily made into fabrics, pipe coverings, and other materials.

Advantages

Pipe and furnace insulation especially in homes.
Hot water and steam pipes are usually coated with asbestos sheets.
Fire Proof

Disadvantages

Asbestos is known to cause several cancers, mainly lung and gastro-intestinal cancers.
Low R-Value

Fiber Glass

Fiber glass pipe insulation is a molded, heavy density, one piece insulation made from inorganic glass fibers bonded with a thermosetting resin.
It is produced in 3 inch lengths with or without a jacket.
R-Value (per inch) is 3.33

Advantages

It is used on mechanical and process piping in power, process and industrial applications, and in commercial and institutional buildings.
Most fiber glass pipe insulations can be used on systems from 0 to 1000°F.

Disadvantages

It is highly costlier and causes skin allergies.

Rock Wool Pipe Insulation

Rock wool (or mineral wool) pipe insulations are precision cut pipe coverings composed of high density mineral wool.
It can be used in a wide range of applications for hot and cold piping ranging from –120°F to 1200°F.
R-Value (per inch) is 3.7

Advantages

This rock wool insulation is frequently used in high temperature industrial process power plants, power stations, petrochemical complexes, etc for steam and process pipe work and for commercial hot/cold water systems.

Disadvantages

Its not a fire proof.
Provide poor insulation when wet.

Elastomers

Elastomers are available in pre-formed shapes and sheets, elastomeric insulations possess good cutting characteristics and low water and vapor permeability.
The upper temperature limit is 104.4°C (220°F).
Elastomeric insulation is cost efficient for low temperature applications with no jacketing necessary.
R-Value (per inch) > 4

Advantages

The easiest and quickest method to insulate already existing pipe work is to use elastomeric (nitrile rubber) insulation material.
High thermal stability.

Disadvantages

It is not a fire-retardant material.

Foamed Plastic

Insulation produced from foaming plastic resins create predominately closed-cellular rigid materials.
They have high thermal resistance (R-Value) value.
R-Value ranges from 3.75 to 7.
Various type of foam insulation materials are:

Polyisocyanurate
Polyurethane
Polystyrene

Usually of the foam insulations, polystyrene is used since it is easier to recycle than polyisocyanurate or polyurethane , it can easily be melted down and reformed into other products.
But, Polystyrene used to blow with CFCs, that destroy the earth's protective ozone layer.
Now Extruded Polystyrene (XPS) uses hydro chloro-fluorocarbons (HCFCs) that are not as dangerous but can still destroy to the earth's protective ozone layer.