Liquiphant FTL41

Summary

Product identification

• Product Name: Liquiphant FTL41
• Type: Vibronic point level switch for liquids

Application

The Liquiphant FTL41 is a point level switch for maximum or minimum detection in tanks, containers, and piping with all types of liquids. It is suitable for hazardous areas and is an alternative to float switches as its function is unaffected by flow, turbulence, air bubbles, foam, vibration, solids content, or buildup.

• Process temperature range: –40 to +150 °C (–40 to +302 °F)
• Pressures: up to 40 bar (580 psi)
• Viscosities: up to 10,000 mPa⋅s

Measuring principle

The device uses a vibrating tuning fork. When the liquid covers the tuning fork, its vibration frequency decreases, triggering the switch.

Output and input variants

The FTL41 is available with several electronic inserts:

• 3-wire DC-PNP (FEL42):
  • Direct current version.
  • Switches load via transistor (PNP).
  • Supply voltage: 10 to 55 VDC.
  • Power consumption: < 0.5 W.
  • Current consumption (without load): ≤ 10 mA.
  • Load current: ≤ 350 mA with overload and short-circuit protection.
• Universal current connection, relay output (FEL44):
  • Switches loads via 2 potential-free changeover contacts (DPDT).
  • Supply voltage: 19 to 253 VAC / 19 to 55 VDC.
  • Power consumption: < 25 VA, < 1.3 W.
  • Connectable load: IAC ≤ 6 A, U~ ≤ AC 253 V; IDC ≤ 6 A to DC 30 V.
• 2-wire NAMUR > 2.2 mA/< 1.0 mA (FEL48):
  • For connection to isolating amplifiers according to NAMUR (IEC 60947-5-6).
  • Signal transmission: 2.2 to 3.8 mA / 0.4 to 1.0 mA.
  • Supply voltage: 8.2 VDC.
  • Power consumption: < 50 mW.

Performance characteristics

• Reference operating conditions: Ambient temperature +23 °C, Process temperature +23 °C, Medium density (water) 1 g/cm³, Viscosity 1 mPa⋅s, Process pressure atmospheric.
• Maximum measured error: ± 1 mm at switch point.
• Hysteresis: Typically 2.5 mm.
• Non-repeatability: 0.5 mm.
• Influence of process temperature: Switch point moves between +1.4 to –2.6 mm in the range –50 to +150 °C.
• Influence of process pressure: Switch point moves between 0 to 2.6 mm in the range –1 to +64 bar.
• Influence of density: Switch point deviation varies with density; specific values are provided in the document for different density settings (> 0.7 g/cm³ and > 0.5 g/cm³).

Mounting

• Mounting location, orientation: Any orientation for devices with short pipe up to approx. 500 mm. Vertical orientation from above for devices with long pipe.
• Minimum distance: 10 mm between tuning fork tip and tank/pipe wall.
• Viscosity considerations:
  • Low viscosity (< 2,000 mPa⋅s): Tuning fork can be positioned within the installation socket.
  • High viscosity (> 2,000 to 10,000 mPa⋅s): Tuning fork must be located outside the installation socket.

Environment

• Ambient temperature range: –40 to +70 °C (plastic housing limited to –20 °C).
• Storage temperature: –40 to +80 °C.
• Humidity: Up to 100%.
• Operating altitude: Up to 2,000 m (extendable to 3,000 m with overvoltage protection).
• Degree of protection: IP66/IP68, NEMA 4X/6P.

Process

• Process temperature range: –40 to +150 °C (–40 to +302 °F).
• Thermal shock: ≤ 120 K/s.
• Process pressure range: Up to 40 bar (580 psi) at 150 °C (dependent on the lowest-rated component, e.g., process connection).
• Density: Standard setting for liquids > 0.7 g/cm³. Optional settings for > 0.5 g/cm³ and > 0.4 g/cm³ (latter not suitable for SIL).
• Viscosity: ≤ 10,000 mPa⋅s.
• Solids contents: particle size ⌀ ≤ 5 mm.

Mechanical construction

• Materials in contact with process: 316L (1.4404 or 1.4435).
• Surface roughness (wetted parts): Ra < 3.2 µm.
• Housing materials: Plastic (PBT/PC) or aluminum (coated).

Certificates and approvals

• CE mark
• RCM marking
• Ex approval (data in separate documentation)
• Overfill protection (WHG approvals)
• Marine approvals
• CRN approval
• China RoHS
• RoHS
• EAC conformity

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Disclaimer: This summary is based on extracted text and may not include all figures, footnotes, or revisions. Contractual data must be verified against the specific OEM PDF revision used for the project.

Official datasheet (PDF)

Lenntech datasheet mirror