Material compatibility reference for valve body and seal selection. Use this chart to verify that your chosen valve materials are suitable for the media in your system.
Ratings are based on ambient temperature (~20°C) and common concentrations. Always verify suitability at your actual operating conditions.
| Chemical | 316 SS | Brass | Carbon Steel | PVC-U | PTFE | EPDM | Viton (FKM) | NBR |
|---|---|---|---|---|---|---|---|---|
| Acetic Acid (dilute) | A | C | C | A | A | A | B | C |
| Ammonia (aqueous) | A | C | B | A | A | A | C | B |
| Benzene | A | B | A | C | A | C | A | C |
| Bleach (Sodium Hypochlorite) | B | C | C | A | A | A | C | C |
| Brine (Sodium Chloride) | A | B | C | A | A | A | A | A |
| Butane | A | A | A | C | A | C | A | B |
| Caustic Soda (NaOH, 50%) | A | C | B | A | A | A | B | A |
| Chlorine Gas (dry) | B | C | C | A | A | C | A | C |
| Diesel Fuel | A | A | A | C | A | C | A | A |
| Ethanol | A | A | A | B | A | A | B | B |
| Glycol (Ethylene) | A | A | A | A | A | A | A | A |
| Hydraulic Oil | A | A | A | C | A | C | A | A |
| Hydrochloric Acid (dilute) | B | C | C | A | A | A | B | C |
| Hydrogen Peroxide (30%) | A | C | C | A | A | A | C | C |
| Methanol | A | A | A | B | A | B | B | C |
| Nitric Acid (dilute, <10%) | A | C | C | A | A | B | A | C |
| Petrol (Gasoline) | A | A | A | C | A | C | A | C |
| Propane | A | A | A | C | A | C | A | B |
| Sea Water | A | B | C | A | A | A | A | A |
| Steam (up to 180°C) | A | B | A | C | A | A | B | C |
| Sulphuric Acid (dilute, <10%) | A | C | C | A | A | B | A | C |
| Water (Potable) | A | A | B | A | A | A | A | A |
The ratings above are based on ambient temperature (approximately 20°C). Chemical resistance can degrade significantly at elevated temperatures. For example, PVC-U is rated to a maximum of 60°C, while PTFE maintains its chemical resistance up to 260°C. Always check the material's maximum service temperature alongside chemical compatibility.
Compatibility can vary dramatically with concentration. A material rated "A" for dilute sulphuric acid may be rated "C" for concentrated sulphuric acid. The ratings in this chart are based on commonly encountered concentrations (noted in parentheses where applicable). Always verify compatibility at your exact concentration.
Real-world applications often involve mixed chemicals, trace contaminants, or pH variations that can alter compatibility. Chloride ions, for example, can cause stress corrosion cracking in stainless steels at elevated temperatures — even in otherwise benign solutions.
This chart is provided as a general guide only. For critical or hazardous applications, always confirm material suitability with the valve manufacturer and/or your chemical supplier. UK Valves Direct can provide detailed material certificates (EN 10204 3.1) and technical data sheets on request.
| Abbreviation | Full Name | Typical Application |
|---|---|---|
| 316 SS | Austenitic Stainless Steel (1.4401) | Valve body — corrosive environments, marine, food-grade |
| Brass | CW617N / CW602N (DZR) | Valve body — potable water, compressed air, general purpose |
| Carbon Steel | ASTM A216 WCB / A105 | Valve body — high-pressure steam, oil & gas |
| PVC-U | Unplasticised Polyvinyl Chloride | Valve body — chemical dosing, water treatment (max 60°C) |
| PTFE | Polytetrafluoroethylene (Teflon™) | Seat & seal — broadest chemical resistance |
| EPDM | Ethylene Propylene Diene Monomer | Seal — water, steam, weak acids/alkalis, ozone-resistant |
| Viton (FKM) | Fluoroelastomer (Viton™ is a DuPont brand) | Seal — hydrocarbons, fuels, oils, solvents, high-temperature |
| NBR | Nitrile Butadiene Rubber (Buna-N) | Seal — oils, fuels, hydraulic fluids (not for ozone or aromatics) |