Technical Data
ComparePoint Level / Liquids
| Measuring Principle | Vibration Liquids |
| Characteristic / Application | Level switch for liquids and is used in tanks, vessels and pipes. |
| Supply / Communication | 20 ... 253V AC/DC, 2-wire 10 ... 30V DC-PNP 3-wire |
| Ambient temperature | -40 °C ... 70 °C (-40 °F ... 158 °F) |
| Process temperature | -40 °C ... 150 °C (-40 °F ... 302 °F) |
| Process pressure / max. overpressure limit | Vacuum ... 40 bar (Vacuum ... 580 psi) |
| Min. density of medium | >0,7g/cm³ (>0,5g/cm³ optional) |
| Main wetted parts | 316L |
| Process connection | Threads: G1/2, G3/4, G1, MNPT1/2, MNPT3/4, MNPT1, R1/2, R3/4, R1 |
| Communication | AC/DC, DC-PNP |
| Certificates / Approvals | CSA C/US, EAC |
| Safety approvals | Overfill protection WHG Leakage |
| Design approvals | EN 10204-3.1 |
| Marine approval | ABS/ LR/ BV/ DNV |
| Options | Adjustment switching delay Cleaned from oil+grease, PWIS free |
If a hygienic connection with clamp is required, select the FTL33.
The Liquiphant FTL31 liquid point level switch is suitable for measurement in all industries, mainly in the mechanical engineering industry. The Liquiphant can be used for overflow protection and pump dry-run protection in cleaning and filter systems as well as in cooling and lubricating vessels.
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Compact:
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- The smallest vibronic sensor on the market
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Safe:
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- Continuous self-monitoring
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- Reliable switching unaffected by the properties of the medium
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Simple:
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- No calibration or adjustment required
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- Plug and play
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Benefits
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Designed to meet the highest quality and environmental sustainability requirements. The self-monitoring Liquiphant switches safely even in the event of a power failure.
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Provides precise switch points unaffected by changes in medium properties
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Even when the medium changes, plug-and-play sensors can be used without adjustment. The measurement is unaffected by conductivity, buildup, turbulence, flow or bubbles
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No calibration, specific knowledge or tools required (e.g. software)
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Rugged stainless steel (316L) with the highest durability - no mechanical moving parts, maintenance-free
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The modular design offers different process temperatures and the widest range of process connections and accessories on the market, meeting every application requirement
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No mechanical moving parts, maintenance-free
Application areas
The FTL31 is a reliable point level switch with a compact design and stainless steel housing. It is suitable for general industrial applications in all industries, for example OEM equipment with limited installation space.
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Process connection: thread
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Temperature: -40...+150 °C (-40...+302 °F)
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Pressure: -1...+40 bar (-14.5...580 psi)
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Surface finish: 3.2 µm
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Certifications: WHG overflow protection and leak detection, CSA C/US, 3.1 material certificate, marine approvals, final inspection report
Replacement for FTL20/FTL260 and FTL31:
FTL20-0010 FTL31-AA1U2AAWBJ
FTL20-001B FTL31-AA1U3AAWBJ
FTL20-0020 FTL31-AA4U2AAWBJ
FTL20-0025 FTL31-AA4M2AAWBJ
FTL20-002B FTL31-AA4U3AAWBJ
FTL20-002D FTL31-AA4M3AAWBJ
FTL20-0110 FTL31-AA1U2AAW5J
FTL20-011B FTL31-AA1U3AAW5J
FTL20-0120 FTL31-AA4U2AAW5J
FTL20-0125 FTL31-AA4M2AAW5J
FTL20-012B FTL31-AA4U3AAW5J
FTL20-012D FTL31-AA4M3AAW5J
FTL20-061B FTL31-AA1U3AAWDJ
FTL20-062B FTL31-AA4U3AAWDJ
FTL20-062D FTL31-AA4M3AAWDJ
FTL260-0010 FTL31-AA1U2BAWSJ
FTL31-AA1U3BAWSJ
FTL260-0020 FTL31-AA4U2BAWSJ
FTL31-AA4U3BAWSJ
FTL260-1010 FTL31-AA1U2BAWSJ
FTL31-AA1U3BAWSJ
FTL260-1020 FTL31-AA4U2BAWSJ
FTL31-AA4U3BAWSJ
Spare Parts & Accessories 40
40 spare parts · click to collapse
| Order code | Description | |
|---|---|---|
| 71280307 | Hirschmann connector M16Consists of: plug connector, screw, seal, valve plug ring, adapter ring. Usage: FTI26, FTL31/FTL33, FTW33, PMC11, PMC21, PMP11, PMP21/PMP23. | Details |
| 71280349 | Hirschmann connector NPTF1/2Consists of: plug connector, screw, seal, valve plug ring, adapter ring. Usage: FTI26, FTL31/FTL33, FTW33, PMC11, PMC21, PMP11, PMP21/PMP23. | Details |
| 71280350 | valve plugConsists of: plug connector, screw, seal, Usage: FTL31/FTL33, FTW33. | Details |
| 52006263 | Process connection | Socket for plug 4p-125V, 4A-M12M12 插头 自连接 M12转成格兰 | Details |
| 52010285 | M12 connector, 90° angled, with 5 m cable适用于M12插头 带5m电缆 PVC材质，铜镀锡/ 镍锁紧螺母 | Details |
| 52018763 | Cable with connector | Cable 4x0.34, box M12, 316L, LED, 9适用于M12插头，集成LED指示 带5m电缆 PVC 材质 316L锁紧螺母 针对卫生型应用 | Details |
| 52010156 | socket wrenchLiquiphant T FTL20/FTL20H | Details |
| 71267011 | Test magnetUsage: FTL20/FTL20H, FTL31/FTL33, FTL50/FTL50H/FTL51/FTL51H, FTW23, FTW33. | Details |
| 52027421 | Compression ringFlush mount FTL20/FTL20H Liquiphant T | Details |
| 71194296 | O-ringProcess gasket DIN7603-A. Usage: process connection, FMI51, FTI51, FTL31/FTL33, FTW23/FTW33. | Details |
| 71185027 | O-ringProcess gasket DIN7603-A. Usage: process connection, FMI51, FMI52, FTI51, FTI52, FMP50, FMP51, FMP56, FMR43, FMR60B, FMR62, QMW43, FTL31, FTL33, FTL41, FTW23, FTW33, FTL50, FTL50H, FTL51, FTL51B, FTL80, FTL81. | Details |
| 52014048 | O-ringProcess gasket for process connections G1 | Details |
| 71258357 | Process connection|Weld-in G3/4, d=29, 316LFlush mount process connection. For pipe-mounting. Material: 316L. Seal: silicone O-ring. FDA, 3-A compliant. additional EPDM O-ring. FDA, EHEDG, 3-A, USP Class VI compliant. Usage: FTL20/FTL20H, FTL31/FTL33, FTW23, FTW33, QMW43. | Details |
| 52028295 | weld socketFlush mount process connection FTL20 "1", FTL20H "GDJ" w/o flange Material: 316L, EHEDG compliant Seal: Silicone O-ring Inspection cert. EN10204-3.1 material (316L wetted parts) | Details |
| 71258355 | Stainless steel connector | Weld-in adapter G3/4 d=50, 316LFlush mount process connection. For vessel-mounting. Material: 316L. Seal: silicone O-ring. FDA, 3-A compliant. additional EPDM O-ring. FDA, EHEDG, 3-A, USP Class VI compliant. Usage: FTL20/FTL20H, FTL31/FTL33, FTW23, FTW33, FMI51, FTI51, QMW43, 11371. Usage: TMR35. | Details |
| 52018765 | weld socketFlush mount process connection FTL20 "1", FTL20H "GDJ", FMI51, FTI51 "GQJ" Material: 316L, EHEDG compliant Seal: Silicone O-ring Inspection cert. EN10204-3.1 material (316L wetted parts) | Details |
| 71675415 | G3/4 brass weld boss blind plugWelding dummy for welding the weld-in adapter G3/4 71258357/52028295, 71258355/52018765. Material: Brass. Usage: FMI51, FTI51, FTL31, FTL33, FTW23, FTW33, TMR35, TM311, TM371, TM372, TM411, TT411. | Details |
| 71675412 | welding boss blind plugBlind plug for closing weld-in adapter G3/4 71258357/52028295, 71258355/52018765. Material: AISI 316L (1.4435). Roughness (process side): Ra < 3.2 μm (126 μin). Silicone O-ring. Usage: FMI51, FTI51, FTL31, FTL33, FTW23, FTW33, 11371, TMR35, TM311, TM371, TM372, TM411, TT411. | Details |
| 71675404 | O-Ring 15.08x2.62 FKM, 5 pcsO-ring set for weld-in adapter G3/4. Material: FKM. Usage: FMI51, FTI51, FTL31, FTL33, FTW23, FTW33, QMW43. | Details |
| 71675405 | O-ring 15,08x2,62 EPDM, 5 pcsO-ring set for weld-in adapter G3/4. Material: EPDM. Usage: FMI51, FTI51, FTL31, FTL33, FTW23, FTW33, QMW43. | Details |
Configurator / Comparison
Measuring principle video
Click to playSource: public information from the Endress+Hauser website
Manuals & Documents 11
All documents for this model11 documents · click to expand
Liquiphant FTL31 Chinese
BA Liquiphant FTL31 IO-Link Chinese
Liquiphant FTL31 English
Liquiphant FTL31 IO-Link English
Liquiphant FTL31 Operating Instructions English
TI 焊接接头、过程转接头和法兰 Chinese
Liquiphant FTL31 Chinese
TI Liquiphant FTL31 IO-Link Chinese
TI Weld-in adapter, process adapter and flanges English
Liquiphant FTL31 English
Liquiphant FTL31 IO-Link English
Case Studies
Municipal Wastewater Treatment · tuning fork — Application Case
Site Conditions
This is a Municipal Wastewater Treatment customer whose plant is at the inlet, biological and outlet stages of a municipal plant. The main task was vibrating-fork point level detection and high/low alarms.
The Problem
The difficulty lies in high solids and corrosive fractions, with large diurnal flow swings; at the same time effluent parameters drift and probes foul with sludge and biofilm. Specification therefore means choosing fork length and surface finish by density and stickiness.
What We Did
We took a level range approach — level solution matched to the actual tank and silo geometry. Delivery was built around choosing fork length and surface finish by density and stickiness, with point-by-point checks on: stable compliance with Grade 1A discharge limits and online data reporting.
Operating Outcome
In service the system performs as intended — no calibration needed, with dependable switching, with routine maintenance falling noticeably.
Food & Beverage · tuning fork — Application Case
Application Context
dosing, pasteurising, filling and CIP stages is a typical Food & Beverage duty. The project started from tuning fork, focusing on vibrating-fork point level detection and high/low alarms.
Process Constraints
frequent cleaning demands instruments that withstand hot CIP/SIP caustic cycles, and syrups, dairy and beverages that scale easily, under strict hygienic requirements only amplify it. The tuning fork specification must therefore cover choosing fork length and surface finish by density and stickiness.
Delivery Approach
Delivery was handled as the level range — level solution matched to the actual tank and silo geometry. Execution centred on choosing fork length and surface finish by density and stickiness, together with food-safety and hygienic design per 3-A / EHEDG.
Field Results
Operation shows the benefit clearly — no calibration needed, with dependable switching, with confidence in this measuring point improving markedly.
Chemical & Pharmaceutical · tuning fork — Application Case
Customer Profile
The typical setting in Chemical & Pharmaceutical is reactors, metering vessels and finished-product tanks. The measuring point is tuning fork; the focus is vibrating-fork point level detection and high/low alarms.
Key Difficulties
Conditions are highly corrosive media with solvents and crystallisation, partly in explosive atmospheres and, on top of that, corrosion plus Ex protection shortens instrument life and makes downtime costly, which a standard configuration cannot handle for long. The design therefore starts with choosing fork length and surface finish by density and stickiness.
Implementation
The scope ran through the level range: level solution matched to the actual tank and silo geometry. Technically it hinges on choosing fork length and surface finish by density and stickiness, and on these requirements: Ex certification and GMP traceability of records.
Customer Benefit
In practice this means no calibration needed, with dependable switching, which cut the workload on the site maintenance team.
Power & Energy · tuning fork — Application Case
Project Background
The project covers boiler feedwater, turbine condensate and FGD/DeNOx systems. The work centres on tuning fork and the core task is vibrating-fork point level detection and high/low alarms.
Operating Challenges
The medium and duty are characterised by high temperature and pressure with both steam and saline water, and drift under high temperature and pressure, with very costly unplanned outages. So tuning fork cannot be specified generically — it calls for choosing fork length and surface finish by density and stickiness.
Solution
The Ainstru engineering team worked through the level range: level solution matched to the actual tank and silo geometry. The configuration involves choosing fork length and surface finish by density and stickiness, with these requirements in view: compliance with power-industry codes and unit availability targets.
Results
Since start-up the system has run steadily; the practical result is no calibration needed, with dependable switching.
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