Why Do Pipes Need Insulation
1. Condensation control
Water vapor may condense on the surface of the pipe if it is operated at temperatures below room temperature.Cause moisture can cause many different types of corrosion, it is often considered important to prevent condensation on the pipes.
Although the surface temperature of the insulation varies with the surface temperature of the pipe,pipe insulation can still prevent the formation of condensation. Condensation does not occur as long as the insulating surface is above the dew point temperature;The insulation layer someway acts like a vapor barrier.It can prevent water vapor from appearing on the surface of the pipe by isolating the water vapor outside the insulation.
2. Frozen Pipe
Because some water pipes are located outside or in unheated areas, the ambient temperature can sometimes drop below the freezing point of the water, so any water in the pipes may freeze.When water freezes, it expands, which in many cases leads to the failure of the piping system.
The pipeline insulation layer cannot completely prevent the water in the pipeline from freezing, but it can extend the time required for freezing, thus reducing the risk of water freezing in the pipeline.Therefore, it is recommended that pipes at risk of freezing be insulated, and local water supply regulations may require that pipes be insulated to reduce the risk of freezing.
For a given length, a small-bore pipe holds less water than a large-bore pipe, so it is easier (and faster) for water to freeze (assuming the equivalent environment) than a large-bore pipe.Due to the greater risk of freezing in small-bore pipelines, insulation is often used in combination with other anti-freezing methods (for example modulating trace heating cable, or ensuring a consistent flow of water through the pipe).
Since the pipeline works at a temperature higher than the ambient temperature, the temperature difference between heating pipelines and the surrounding environment is large, and the heat loss of the pipeline is also large. Therefore, the Thermal Insulation of the pipeline is introduced to reduce the heat loss.
The thickness of the Thermal Insulation used to save energy varies, but in general, a pipe that runs at a higher temperature will get more heat flow, and thicker materials mean more energy savings.
The location of the pipe also affects the thickness of the Thermal Insulation.For example, in some cases, heating pipes in a well-insulated building may not need Thermal Insulation because the "lost" heat (heat flowing from the pipes to the surrounding air) may be considered "useful" for indoor temperature control.This "lost" heat will be effectively trapped indoor by the building's structural insulation.In contrast, if the pipe passes through an overheated room or an area that does not need heating, this type of pipe can be insulated.
Prevention of Extreme Temperature
For very high or very low temperature pipe, Insulation Material must be used.No matter the temperature is too high or too low, it will hurt people.Standards for limit temperatures vary from country to country, but there are some international standards that limit the recommended touchable temperature range.
Because the surface temperature of the insulating material is different from that of the pipe surface, the surface temperature of the Insulation Material is usually much warmer, which allows the contact temperature of the outer surface to be controlled within a safe range.
Pipes can be used to transmit noise from one part of a building to another (typical example: waste water pipes in a building).Acoustic materials can reduce the vibration of the pipe and reduce the noise.
Factors affecting the performance of insulation layer
Thermal conductivity ("k" or "λ" value)
Surface emissivity ("ε" value)
Water-vapour resistance ("μ" value)
Pipe insulation materials come in many forms, but most of them fall into one of the following categories.
Mineral wool, including rock wool and slag wool, is the insulating layer made of mineral fibers held together by organic binder.After testing, the mineral wool can run in high temperature, and has a good fire performance grade.
Mineral wool is used in all types of piping, especially industrial piping that operates at higher temperatures.
Glass wool is a kind of high temperature fiber insulation material similar to mineral wool. Glass fibers are held together by adhesive.
Like other forms of mineral wool, glass wool insulation materials can be used for insulation and noise reduction.
Elastomeric Insulation is highly resistant to water vapor, so they usually do not need additional vapor barrier.Such high vapor resistance, combined with the high surface emissivity enables a thin Elastomeric Insulation to have the performance of resistance to surface condensation.
Therefore, Elastomeric Insulation are widely used in air conditioning pipes and refrigeration pipes.Flexible Elastomeric Insulation materials are also used in heating or hot water systems.