The Liquiphant FailSafe is a point level switch for
minimum and maximum detection (MIN/MAX) which
can be used in liquids:
- Process temperatures –60 to 280 °C (–76 to 536 °F)
- Ambient temperatures –60 to 70 °C (–76 to 158 °F)
- For highly corrosive media
- Pressures up to 100 bar (1450 psi)
- Viscosity up to 10000 mPa·s
- Density from 0.4 g/cm3 (0.4 SGU)
Liquiphant FailSafe is the reliable point level switch for
MIN and MAX safety applications up to SIL3.
Outstanding features of the point level switch are its fail-
safe design and its high availability.
A permanent LIVE signal also monitors function safety.
Point level detection
- 4-20 mA interface (acc. to NAMUR NE 06/NE 43): easy integration via the switching unit (Nivotester FailSafe FTL825) with a two-channel output (safety contacts) and locking function or direct integration into a safety PLC
- Use in safety systems requiring functional safety to SIL3 in accordance with IEC 61508 Ed.2.0/IEC 61511-1/ISA 84-1 and DIN EN ISO 13849
- Proof test: proof testing interval up to 12 years
- Slave devices tested at the press of a button
- Permanent self-monitoring/internal redundancy
- No adjustment: quick, low-cost startup
- No mechanically moving parts: no maintenance, no wear, long operating life
- Monitoring of fork for damage, corrosion, buildup and mechanical blocking
- 2. process seal (2 nd line of defense) is provided as standard in the high-temperature version or can be optionally selected for all other versions
Maximum or minimum detection for liquids in tanks or pipes (leak monitoring, dry running protection/pump
protection or overfill protection), particularly for the chemical, energy and oil & gas industry.
Special versions are suitable for use in hazardous areas and for applications with high pressures. As a coated
version, the Liquiphant FailSafe is highly resistant to corrosion, making it particularly suitable for very
The point level switches make a distinction between two states: "covered" and "exposed" Depending on whether you have selected the MIN (minimum detection) or MAX (maximum detection) operating mode, this results in two specific scenarios in each case: the "Good" state and demand mode.
The fork is covered in the MIN operating mode (e.g. pump protection).
The fork is exposed (uncovered) in the MAX operating mode (e.g. overfill protection).
The fork is exposed (uncovered) in the MIN operating mode (e.g. pump protection).
The fork is covered in the MAX operating mode (e.g. overfill protection).
The sensor's fork vibrates at its intrinsic frequency. When the tuning fork is immersed in a liquid, its intrinsic
frequency changes due to the change in density of the surrounding medium. This change in frequency causes
the current signal to switch.