The material selection for electromagnetic flow meters mainly involves two parts: electrodes and lining. It needs to be matched according to the corrosiveness, temperature, and abrasiveness of the medium. The following are common material classifications and applicable scenarios:

I. Electrode Materials

1. 316L Stainless Steel: Suitable for ordinary media or slightly corrosive liquids; a general-purpose choice.

2. Titanium (Ti): Resistant to alkaline solutions, such as seawater and chlorides.

3. Tantalum (Ta): Resistant to acidic solutions (except hydrofluoric acid and fuming sulfuric acid); suitable for strong acid environments.

4. Platinum Alloy: Used in complex operating conditions involving alternating strong acids and alkalis.

5. Tungsten Carbide: Highly wear-resistant; suitable for liquids containing impurities or particles.

II. Lining Materials

1. Polytetrafluoroethylene (PTFE): Resistant to strong acids, strong alkalis, and organic solvents, but with relatively poor wear resistance; applicable temperature range: -30~100℃.

2. Chloroprene Rubber (CR): Moderate wear resistance; resistant to low concentrations of acids and alkalis; applicable temperature range: -20~60℃; commonly used for water and wastewater. 3. Polyurethane rubber (PU): Excellent abrasion resistance, but weak acid and alkali resistance; suitable for slurries and muds.

3. Perfluoroethylene propylene (PFA/F46): Chemical stability close to PTFE, with higher compressive strength.

4. Ceramic: High temperature and corrosion resistance, but higher cost.

III. Selection Recommendations

1. Conventional liquids: PTFE lining + 316L electrode.

2. Corrosive liquids: Select titanium (alkali), tantalum (acid), or platinum alloy electrodes based on acidity or alkalinity.

3. Liquids containing particles: Tungsten carbide electrode + abrasion-resistant lining (such as polyurethane).

The specific material should be selected comprehensively based on the characteristics of the medium, temperature, pressure, and other parameters.