The maximum temperature and pressure of an electromagnetic flow meter (EMF) are primarily limited by the liner material, electrode seals, coil insulation class, and flange rating. Below is a structured breakdown of standard and extreme limits.
1. Maximum Temperature Ratings (by Liner Material)
Rubber (NR/EPDM/CR)
Continuous: ‑10 °C to +80 °C (14 °F to 176 °F)
Short peak: +90 °C (194 °F)
Best for: Water, wastewater, sewage, weak acids/bases (pH 4–10)
PTFE (Teflon®)
Continuous: ‑40 °C to +130 °C (‑40 °F to 266 °F)
Short peak: +150 °C (302 °F)
Note: Above 130 °C, vacuum resistance drops significantly
PFA (Perfluoroalkoxy)
Continuous: ‑40 °C to +180 °C (‑40 °F to 356 °F)
Short peak: +200 °C (392 °F)
High‑temp version: Rated for 180 °C continuous (with H‑class coil insulation)
Ceramic (Alumina)
Continuous: ‑40 °C to +200 °C (‑40 °F to 392 °F)
Best for: High‑temp, abrasive, or ultra‑corrosive fluids
Coil Insulation Limit:
Class E: ≤120 °C (248 °F)
Class H: ≤180 °C (356 °F) (required for PFA high‑temp models)
2. Maximum Pressure Ratings
Standard Industrial EMFs (Flange‑type)
Standard: PN16 / PN25 (16–25 bar / 230–363 psi)
High‑pressure: PN40 (40 bar / 580 psi) (common for PFA/PTFE liners)
Ultra‑high‑pressure: PN100 / ASME Cl 600 (100 bar / 1,450 psi) (specialized models, e.g., KROHNE OPTIFLUX 4300)
Extreme: Up to 1,500 bar (21,750 psi) (custom high‑pressure sensors for oil/gas)
Liner‑Based Pressure Limits
Rubber: Max PN25 (25 bar) (risk of delamination at higher pressure)
PTFE: Max PN40 (40 bar); not for vacuum (collapses under negative pressure)
PFA: Max PN40 (40 bar); excellent vacuum resistance (‑1 bar / 29.9 inHg)
Post time: May-11-2026