Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| aqueous | C | D | |
| concentrated | C | D |
Material comparison at 20 °C
Resistance overview
Aluminium maintains a consistent rating of C across all 2 tested concentrations (aqueous, concentrated) of Calcium Hydroxide at 20 °C. The fact that the rating does not change with concentration within the tested range simplifies material selection, though the boundary conditions beyond this range remain untested. However, at 50 °C the resistance rating drops, indicating that temperature must be factored into the design. For heated applications, additional testing under actual service conditions is strongly recommended.
Application context
Calcium Hydroxide is commonly encountered in water treatment and cleaning and sanitation. Aluminium (Aluminium) is a metal typically used for vessels, heat exchangers, fittings and structural components. The compatibility between these two is therefore an important consideration for engineers and procurement teams selecting containment, transfer, or processing equipment.
Practical recommendation
Aluminium has limited resistance to Calcium Hydroxide and should only be used for short-term or intermittent contact at ambient temperature. The C rating means the material undergoes noticeable changes — swelling, loss of strength, or surface degradation — that make it unsuitable for permanent installations. For prolonged or continuous exposure, HDPE, LDPE, Nylon (PA) offer significantly better resistance and are rated A.
Did you know?
Temperature is often the deciding factor when selecting materials for Calcium Hydroxide: even materials rated A at 20 °C may lose performance at elevated temperatures.
Materials rated A or B at 20 °C
Based on the row for concentrated, 20 °C.
- Thermoplastics
- HDPE A, PP A, PVC Rigid A, LDPE A, Nylon (PA) A, Acetal (POM) A, PVC Flexible A, Polystyrene B, Polysulfone B, PETG A, PMP A
- Fluoropolymers
- PTFE A, PVDF A, FEP A, ECTFE/ETFE A
- Elastomers
- EPDM A, Viton (FPM) A, NBR A
- Metals
- SS 316 A, SS 304 A
About Aluminium
Aluminium relies on a thin oxide layer. Strong acids, strong alkalis and mercury compounds destroy that layer.
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
About this data
The ratings come from the chemical resistance list published by Bürkle GmbH, which compiled them from raw-material manufacturers’ data. They describe laboratory tests on the raw material at 20 °C and 50 °C.
A finished part also sees pressure, mechanical stress, welds and mixtures that a laboratory test does not. Treat the rating as a first filter and test under your own conditions before relying on it.