Difference between revisions of "Pipe Insulation"

[[Category:Piping]]{{Knoppen}}

[[File:Pipe Insulation.jpg|thumb|right|Pipe Insulation]]

[[File:Pipe Insulation1.jpg|thumb|right|Pipe Insulation]]

'''Pipe Insulation''' is thermal or acoustic insulation used on pipework.

==Applications==

===Condensation control===

* the insulation surface is above the dewpoint temperature of the air;

* the insulation incorporates some form of water-vapour barrier or retarder that prevents water vapour from passing through the insulation to form on the pipe surface.

===Pipe freezing===

Since some water pipes are located either outside or in unheated areas where the ambient temperature may occasionally drop below the freezing point of water, any water in the pipework may potentially freeze. When water freezes, it expands due to negative thermal expansion, and this expansion can cause failure of a pipe system in any one of a number of ways.

The location of pipework also influences the selection of insulation thickness. For instance, in some circumstances, heating pipework within a well-insulated building might not require insulation, as the heat that's lost i.e., the heat that flows from the pipe to the surrounding air may be considered useful for heating the building, as such lost heat would be effectively trapped by the structural insulation anyway.Conversely, such pipework may be insulated to prevent overheating or unnecessary cooling in the rooms through which it passes.

===Protection against extreme temperatures===

Where pipework is operating at extremely high or low temperatures, the potential exists for injury to occur should any person come into physical contact with the pipe surface. The threshold for human pain varies, but several international standards set recommended touch temperature limits.

Since the surface temperature of insulation varies from the temperature of the pipe surface, typically such that the insulation surface has a less extreme temperature, pipe insulation can be used to bring surface touch temperatures into a safe range.

===Control of noise===

Pipework can operate as a conduit for noise to travel from one part of a building to another . Acoustic insulation can prevent this noise transfer by acting to damp the pipe wall and performing an acoustic decoupling function wherever the pipe passes through a fixed wall or floor and wherever the pipe is mechanically fixed.

Pipework can also radiate mechanical noise. In such circumstances, the breakout of noise from the pipe wall can be achieved by acoustic insulation incorporating a high-density sound barrier.

==Materials==

Pipe insulation materials come in a large variety of forms, but most materials fall into one of the following categories.

===Mineral wool===

Mineral wools, including rock and slag wools, are inorganic strands of mineral fibre bonded together using organic binders. Mineral wools are capable of operating at high temperatures and exhibit good fire performance ratings when tested.Mineral wools are used on all types of pipework, particularly industrial pipework operating at higher temperatures.

===Glass wool===

Glass wool is a high-temperature fibrous insulation material, similar to mineral wool, where inorganic strands of glass fibre are bound together using a binder.As with other forms of mineral wool, glass-wool insulation can be used for thermal and acoustic applications.

===Flexible elastomeric foams===

These are flexible, closed-cell, rubber foams based on NBR or EPDM rubber. Flexible elastomeric foams exhibit such a high resistance to the passage of water vapour that they do not generally require additional water-vapour barriers. Such high vapour resistance, combined with the high surface emissivity of rubber, allows flexible elastomeric foams to prevent surface condensation formation with comparatively small thicknesses.

As a result, flexible elastomeric foams are widely used on refrigeration and air-conditioning pipework. Flexible elastomeric foams are also used on heating and hot-water systems.

===Rigid foam===

Pipe insulation made from rigid Phenolic, PIR, or PUR foam insulation is common in some countries. Rigid-foam insulation has minimal acoustic performance but can exhibit low thermal-conductivity values of 0.021 W/(m·K) or lower, allowing energy-saving legislation to be met whilst using reduced insulation thicknessess.

===Polyethylene===

Polyethylene is a semi-flexible plastic foamed insulation that is widely used to prevent freezing of domestic water supply pipes and to reduce heat loss from domestic heating pipes.

The fire performance of Polyethylene usually prohibits its use in commercial buildings.

===Cellular Glass===

100% Glass manufactured primarily from sand, limestone and soda ash.

===Aerogel===

Silica Aerogel insulation has the lowest thermal conductivity of any commercially produced insulation. Although no manufacturer currently manufactures Aerogel pipe sections, it is possible to wrap Aerogel blanket around pipework, allowing it to function as pipe insulation.The usage of Aerogel for pipe insulation is currently limited.

==Sources==

[http://en.wikipedia.org/wiki/Pipe_insulation Wikipedia Pipe insulation]