Understanding Wetted Materials (Stainless, Plastics, & Elastomers)
Wetted materials are a reference to the sub-components of the sensor that are in contact with the process media. These materials should be considered based on their chemical resistance and compliance with regulatory specifications as required by the manufacturing process. A list of the wetted materials is included with the Declaration of Quality (DOQ) shipped with Hamilton products. Additionally, material specifications formatted to comply with EN 10204-2.1 can be accessed in the certificate area of the website.
Metals
Most metallic components used in Hamilton sensors are designated by their Werkstoff number. The Werkstoff numbering system was developed by DIN “Deutsches Institut für Normung” (German Institute for Standardization) and is prevalent naming convention in Europe. AISI and UNS naming conventions are more common in North America. Other common naming conventions are listed in the chart below.
| Hamilton (DIN) | AISI / SAE | UNS | Other Common Names |
|---|---|---|---|
| Stainless Steel 1.4404 | 316L Stainless | UNS S31603 | SS2348 X2CrNiMo1810 |
| Stainless Steel 1.4435 | 316L Stainless | UNS S31603 | SS2353 X2CrNiMo18143 |
| Stainless Steel 1.4571 | 316Ti Stainless | UNS S31635 | SS2350 X10CrNiMoTi1810 |
| Stainless Steel 2.4602 | --- | UNS N06022 | Inconel ® alloy 22 Hastelloy ® C-22 |
| Titanium 3.7035 | Titanium Grade 2 | UNS R50400 | Commercially Pure Titanium |
Plastics
Plastic materials used in Hamilton sensors are selected based pressure, temperature, and chemically inert properties. The plastics are also chosen for compliance with FDA and USP regulations. The commonly accepted, generic abbreviations for these plastics are used in Hamilton documentation.
| Hamilton Abbreviation | Chemical Nomenclature | Other Common Names |
|---|---|---|
| PEEK | Polyetheretherketone | PEEK LSG / FG (Life Science Grade / Food Grade) |
| PTFE | Polytetrafluoroethylene | Teflon ® |
| PVDF | Polyvinylidene Fluoride | Kynar ® |
| PP | Polypropylene | --- |
Elastomers
The elastomers used in Hamilton sensors are typically o-ring seals. Similar to the plastics, the elastomer materials are chosen for their chemical resistance and compliance with FDA, USP and EU regulations. The generic abbreviation for each elastomer is used on Hamilton documentation.
| Hamilton Abbreviation | Chemical Nomenclature | Other Common Names |
|---|---|---|
| EPDM | ethylene propylene diene monomer | --- |
| FFKM | perfluoroelastomer (per ASTM) | Kalrez ® |
| VQM | silicone | --- |
| FKM | fluoroelastomer (per ASTM) | Viton ® |
Other Wetted Materials
pH sensors include borosilicate glass and ceramic as part of their wetted materials. Platinum is used on ORP sensors, Incyte cell density sensors, and some variations of the Conducell conductivity sensors. Graphite (carbon) is an electrode material in the the Conducell 2DC-PG sensor.
Related Content
- See examples of the documentation and certificates provided with Hamilton Sensors and liquid calibration solutions.
- Learn more about how Hamilton specifies surface finish of wetted component.
- New to process sensors? Visit our General Sensor Article Page to see similar content.