What it is

The Liquiphant FTL64 is a point-level switch (limit level detector) manufactured by Endress+Hauser. It uses a vibronic measurement principle (a vibrating fork) to detect the presence or absence of liquid at a given point (i.e., a “limit” or “alarm” level) in a tank, vessel or pipeline.
It is designed specifically for high‐temperature and demanding industrial applications (hot liquids, pumpable fluids, high pressures).

How it works

• The device contains a “fork” or “tuning-fork” (vibrating element) that is excited at a known frequency. When immersed in the liquid, the vibration is damped; when the liquid is absent, the damping changes. That change is detected and signals the switch. (General vibronic principle)
• Because it’s a point detector, it gives a “liquid present / liquid not present” signal, rather than a continuous level measurement.
• The FTL64 is offered with digital communication options, diagnostics (Heartbeat Technology by Endress+Hauser) and supports modern asset management and smart commissioning via e.g., Bluetooth/SmartBlue app.

Key Specifications & Features

Here are some of the standout technical specifications and features (note: always check the exact model variant for your application):

• Process temperature range: from –60 °C up to +280 °C. In some versions, up to +300 °C (for limited period) and with PFA coating up to ~230 °C.
• Process pressure range: from vacuum up to ~100 bar (depending on variant) for the normal version; PFA coated versions have lower pressure limit (e.g., up to ~40 bar) in some cases.
• Medium density (min.): typical minimum ~0.5 g/cm³ (optionally 0.4 g/cm³) for the liquid to be detected.
• Viscosity capability: Up to ~10,000 mm²/s (cSt) — suitable for “pumpable” liquids/fluids.
• Materials / coatings: Choice of wetted materials (e.g., 316L stainless steel) and optional PFA coating for aggressive media.
• Process connections: Threads, flanges, hygienic connections (Tri-Clamp) for varied installation requirements.
• Safety & approvals: Developed per IEC 61508; rated for SIL2/3 in some variants; certifications for explosion protection, marine approvals, over-fill protection (e.g., WHG) included.
• Diagnostics & maintenance: Heartbeat technology enables continuous diagnostics; guided proof testing via app or test pin/button from outside — simplifying safety loop testing.

Where / Why You Would Use It

Typical application scenarios for the FTL64 include:

• High‐temperature liquids in industrial processes (e.g., chemical, petrochemical, power generation) where pumps, pipelines or vessels need level detection in hot fluid conditions.
• Over-fill protection of tanks storing hot liquids. The robust design suits extreme temperature conditions.
• Dry‐run protection for pumps in hot liquid systems (i.e., detecting when liquid level drops below pump suction).
• Applications where alternatives (float switches, optical sensors) fail due to temperature, viscosity, media aggressiveness, deposits, bubbles or other difficulties. The vibronic switch is less sensitive to such interferences.

In short: when you need a reliable level switch under harsh conditions (high T, possibly high pressure, viscous or aggressive media) — this product fits that niche.

Benefits / Key Advantages

• High reliability even in tough environments: high T, high P, viscous fluids.
• Simple yet robust limit detection: less maintenance than some more complex level measurement technologies in harsh conditions.
• Strong safety features and diagnostics built-in: ideal for critical installations requiring SIL/over-fill protection.
• Flexibility of installation: multiple connection types, materials, coatings make it adaptable.
• Modern commissioning/maintenance: Bluetooth/SmartBlue app, heartbeat diagnostics simplify asset management and reduce downtime.

Considerations / Things to Check

• Ensure the version you select supports your maximum process temperature – e.g., if you will exceed +230 °C, ensure the variant supports up to +280 °C (or the short term +300 °C).
• Check the pressure rating for your specific application and verify the process connection’s rating as this may define the maximum safe pressure.
• Minimum medium density must be met: if you have extremely low‐density liquids, check whether the 0.4 g/cm³ option is needed.
• For highly aggressive media, consider the PFA-coated variant — but note that for PFA coated version the pressure/temperature limits may differ (lower) so review carefully.
• Even though it is robust, ensure good installation practice: correct immersion, location free of unwanted turbulence or splashing, correct orientation, and maintenance access for proof testing.
• Check compatibility with your control and safety system: output signals, diagnostics, communication (HART, Bluetooth etc) must integrate with your system.
• Consider the lifecycle & document the proof-testing regime: for safety critical usage (SIL, over-fill protection) you’ll want documented testing/maintenance procedures.