How to Read a Refractory Technical Datasheet
When specifying refractory materials, a technical datasheet provides important information about a material’s physical, thermal and mechanical properties.
However, you should not view individual figures in isolation. Maximum service temperature, bulk density, thermal conductivity and mechanical strength each tell you something different about how a refractory material behaves.
Understanding what these values mean can make it easier to compare refractory materials and determine whether their stated properties meet the requirements of your specification.
Here are some of the key properties you may find on a refractory technical datasheet and what they mean.
1. Maximum Service Temperature
Maximum service temperature indicates the upper temperature at which a refractory material is intended to operate.
When looking at a refractory material, the temperature rating is a good place to start, but a higher rating doesn’t mean that one material is better than another.
The actual operating environment also needs to be considered, including temperature fluctuations, atmosphere, chemical exposure and mechanical conditions.
This means maximum service temperature should be considered alongside the other properties listed on the technical datasheet.
2. Bulk Density
Bulk density describes the mass of a refractory material in relation to its overall volume, including its pore structure.
This property can provide useful information about the physical characteristics of a refractory.
Dense and insulating refractory materials, for example, can have very different bulk densities because they are designed to perform different functions.
Bulk density can also relate to other characteristics including thermal conductivity, porosity and mechanical properties, so it should be considered as part of the wider material specification rather than as an isolated measurement.
3. Thermal Conductivity
Thermal conductivity describes how effectively heat passes through a material.
For some refractory applications, reducing heat transfer is a priority. Insulating refractories are designed to limit heat loss and support thermal efficiency.
Other applications require greater heat transfer, making materials with higher thermal conductivity more appropriate to the specification.
Technical datasheets may provide thermal conductivity values at different temperatures, as the performance of a refractory material can change as operating temperatures increase.
Understanding whether an application requires insulation or heat transfer is therefore an important part of interpreting this figure.
4. Mechanical Strength
Refractory components can experience more than high temperatures. Depending on the application, they may also be subjected to physical loads and stresses during operation.
Technical datasheets can include different measurements relating to mechanical strength depending on the material and intended application.
These figures provide information about how the material behaves when subjected to particular forms of mechanical stress.
As with other refractory properties, the required level of mechanical strength will depend on the customer’s application and specification.
5. Porosity
Porosity refers to the proportion of voids or pores within a refractory material.
The level and structure of porosity can influence several other material characteristics, including density, thermal behaviour and interaction with substances encountered during operation.
This can be particularly important in environments involving gases, molten materials or chemically aggressive substances.
When comparing technical datasheets, porosity should therefore be considered alongside density, chemical compatibility and the wider operating environment.
6. Thermal Expansion
Refractory materials expand and contract as their temperature changes.
Thermal expansion data provides information about how much dimensional change can occur as the material is heated.
This can be particularly relevant where components operate through repeated heating and cooling cycles or where dimensional tolerances are important to the application.
Understanding this characteristic allows engineers and specifiers to account for the expected material behaviour in their own designs and specifications.
7. Chemical Composition
A technical datasheet for a refractory material may also include information about its chemical makeup.
Composition is important because different refractory materials offer different properties and levels of compatibility with the environments in which they operate.
Vulcan manufactures refractory products from a range of established material formulations, including silicon carbide, zirconia and zircon-based materials, high alumina insulating materials and hybrid mullite-silicon carbide refractories.
The appropriate formulation and required properties depend on the customer’s specification and intended application.
Why Refractory Technical Data Should Be Considered as a Whole
One of the most important things to remember when reading a refractory technical datasheet is that no single value tells the complete story.
A material could offer excellent performance in one area while having very different characteristics in another.
For example, an application requiring effective thermal insulation will have different material requirements from one where high thermal conductivity is important. Similarly, a material operating at a suitable temperature may still need to meet specific mechanical or chemical requirements.
Technical data should therefore be considered collectively and against the requirements established by the engineer or specifier.
Comparing Refractory Material Technical Datasheets
When comparing refractory materials, consider:
- Maximum Service Temperature
- Bulk Density
- Thermal Conductivity
- Mechanical Properties
- Porosity
- Thermal Expansion
- Chemical Composition
- Relevant Test Conditions
It’s also important to check that values are being compared on a like-for-like basis. Different test methods, temperatures, and measurement conditions can all affect the figures shown.
Technical datasheets should therefore be used to understand the characteristics of each material rather than simply identifying which product has the highest or lowest individual value.
Refractory Technical Data from Vulcan Refractories
Vulcan Refractories manufactures refractory products to customer specification using a range of proven material formulations.
Technical information is available across our refractory material ranges to help engineers, specifiers and customers understand the characteristics of the materials we manufacture.
Our refractory ranges include silicon carbide, zirconia and zircon-based materials, high alumina insulating refractories and hybrid mullite-silicon carbide materials for demanding industrial applications.
Explore our refractory materials and technical product information or contact Vulcan Refractories to discuss your manufacturing requirements.