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Brand: Endress+Hauser (E & H)
Endress+Hauser FTL81 Liquiphant FailSafe Level Switch, Pipe
Description
Endress+Hauser FTL81 Liquiphant FailSafe level switch with extension pipe
The Endress+Hauser FTL81 is the extension-pipe version of the Liquiphant FailSafe family. It is a vibronic point level switch for MIN and MAX safety functions up to SIL 3 (IEC 61508 and IEC 61511-1), working on a 2-wire 4–20 mA loop with a permanent LIVE signal. The pipe lets the fork reach a precise level inside a tank, even when the nozzle sits on the roof, for overfill protection or dry-run protection. Seven Star LLC supplies the FTL81 in Oman and the GCC as an independent supplier in Muscat.
Where the compact FTL80 is limited to a sensor length of 80 mm, the FTL81 offers a short pipe version (115 to 118 mm on G threads) and a variable pipe extension from 148 to 3,000 mm. The process temperature range is –60 to +280 °C, with up to 300 °C for 50 hours cumulative, and pressure is up to 100 bar.
FTL81 technical specifications
| Parameter | Specification |
|---|---|
| Manufacturer / part number | Endress+Hauser / FTL81 (Liquiphant FailSafe, extension pipe) |
| Function | MIN or MAX point level safety switch, up to SIL 3 |
| Process temperature | –50 to +150 °C, or –60 to +280 °C; liquefied gas –50 to +60 °C |
| Process pressure | Up to 64 bar or 100 bar, depending on version and flange |
| Sensor length | Short pipe G ¾ 115 mm, G 1 118 mm, flush-mount G 1 104 mm; pipe extension 148 to 3,000 mm (maximum 3 m) |
| Output and supply | 2-wire 4–20 mA with 0.25 Hz LIVE signal; 12 to 30 V DC, below 660 mW |
| Hysteresis / repeatability | About 2 mm / 0.1 mm; maximum error ±1 mm |
| Viscosity | MAX up to 10,000 mPa·s; MIN up to 350 mPa·s; 100 mPa·s in MIN at 230–280 °C |
| Wetted materials | 316L (1.4435) with Alloy C22 option; 318L (1.4462) fork on high-temperature version |
| Weight of extension | 0.9 kg per 1,000 mm; process connection thread 0.2 to 0.33 kg |
| Ambient temperature | –40 to +70 °C, with optional –50 or –60 °C |
| Mechanical load | Maximum lateral load of pipe extension 75 Nm |
| Proof test | Interval up to 12 years, started at the press of a button |
How the FTL81 signals level and faults
A tuning fork is excited at its natural frequency, and covering it with liquid lowers that frequency. The FTL81 translates that state into current: 18.5 mA to 9.0 mA in minimum mode and 13.5 mA to 6.0 mA in maximum mode, with a continuous 0.25 Hz live signal in the OK state. Anything below 3.6 mA is a fault under NAMUR NE43. Because the OK state carries a visible signal, a broken cable, dead electronics or a blocked fork will not look the same as a healthy device, which is what makes the loop suitable for a safety function.
The viscosity limits depend on the safety mode, which is why the safety manual should be read together with the datasheet: maximum detection allows up to 10,000 mPa·s, but minimum detection is limited to 350 mPa·s, and to 100 mPa·s at 230 to 280 °C.
FTL81 compared with the FTL80 and FTL85
The FTL81 shares its electronics, current levels, supply and approvals approach with the FTL80, so the difference is mainly mechanical: the FTL81 has a pipe. The FTL85 is the coated FailSafe model for aggressive liquids, limited to 40 bar and 150 °C. A mixed installation can use all three on the same Nivotester FailSafe FTL825 channels or the same safety PLC cards, as they speak the same 4–20 mA language. For general-purpose duties without the live signal, the FTL51B with pipe extension to 6 m is the usual option.
FTL81 selection and ordering checklist
- Required fork position: distance from the sealing surface to the switch point, including nozzle height and insulation.
- Short pipe or free extension length, up to 3,000 mm; check support needs for long probes and turbulent liquids.
- MIN or MAX function, density combination, viscosity and liquefied gas duty.
- Temperature and pressure class (150 or 280 °C; 64 or 100 bar) and second line of defense.
- Thread (G, NPT, R in ¾ or 1) or flange (EN, ASME, JIS); wetted material 316L or Alloy C22.
- Housing F16, F13, F17, F15, F27 or T13, and cable entry or M12 plug.
- Ex, WHG, marine, CRN and test certificates; marine use with extensions longer than 1,600 mm needs additional support.
Installing and commissioning the FTL81
A probe with a pipe up to about 500 mm can be installed in any orientation; longer probes should be mounted vertically from above. Dynamic loads from agitators or flow require a support, and the lateral load on the pipe must stay under 75 Nm. The flow velocity limit quoted in the datasheet is 5 m/s at 1 mPa·s and 1 g/cm³. Align the fork so that its narrow sides face up and down.
On start-up set the two density switches, select MIN or MAX by connection coding, check the live signal in the evaluator and carry out the function test. Define a proof-test schedule from the safety manual, and keep a spare insert. Inspect the pipe and fork at turnarounds for corrosion and buildup.
FTL81 applications in Oman and the GCC
The FTL81 is a typical high-level shutdown switch on atmospheric storage tanks for diesel, crude and chemicals, where the pipe carries the fork down from a roof nozzle to the alarm level. It also serves as a low-level pump protection on long vertical vessels, hot oil tanks up to 280 °C and liquefied gas vessels.
FTL81 probe length options
| Probe design | Length | Use |
|---|---|---|
| Short pipe, G ¾ | 115 mm to sealing surface | Short pipe version for shallow reach |
| Short pipe, G 1 | 118 mm (104 mm flush mount) | Short pipe version, with a flush-mount variant |
| Pipe extension | 148 to 3,000 mm | Roof-mounted fork at set level |
| Maximum sensor length | 3 m (10 ft) | Upper limit stated in the datasheet |
Information to send with an RFQ for the FTL81
- Order code or tag data, and any existing Liquiphant being replaced.
- Liquid properties, temperature, pressure, MIN or MAX function and SIL target.
- Exact insertion length needed and nozzle details.
- Thread or flange standard, size and rating, and housing and entry preference.
- Approvals, documents and quantity, with delivery point in Oman or the GCC.
Documents and quotation
A datasheet (Technical Information) for the Endress+Hauser FTL81 is attached on this page. Safety data and proof-test steps are in the separate safety manual.
Send the FTL81 order code, or the probe length and process data from the checklist, and Seven Star LLC will return availability and lead time for Oman and the GCC.
Other Models in the Eh Liquiphant Failsafe Ftl Range
Seven Star LLC supplies models from the Eh Liquiphant Failsafe Ftl range in Oman and the GCC. Compare the related models below and request a quote for the one that matches your application.
| Model | Category | |
|---|---|---|
| Endress+Hauser FTL80 Liquiphant FailSafe Compact Level Switch | Level Instrumentation | View details |
| Endress+Hauser FTL81 Liquiphant FailSafe Level Switch, Pipe | Level Instrumentation | You are viewing this model |
Datasheets & Documents
- Datasheet Endress+Hauser FTL81 Datasheet Download
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About brand
Endress+Hauser makes process measurement instruments for flow, level, pressure, temperature and liquid analysis. Georg H. Endress and Ludwig Hauser started the business in Lörrach, Germany, on 1 February 1953, first selling level meters, and the Endress+Hauser name has been used since 1957. The group is headquartered in Reinach, Switzerland, and has been wholly owned by the Endress family since 1975.
Seven Star LLC is an independent supplier listing Endress+Hauser flowmeters, level and pressure transmitters, temperature assemblies and liquid analysis products for buyers in Oman and the GCC. Instruments are matched from the full order code on the nameplate.
Endress+Hauser company profile
| Origin | Founded in Lörrach, Germany, on 1 February 1953 by the Swiss engineer Georg H. Endress and Ludwig Hauser |
|---|---|
| Headquarters | Endress+Hauser AG, Reinach (Basel-Landschaft), Switzerland |
| Ownership | Family owned; the Endress family has been the sole shareholder since 1975, and a family charter commits the company to stay family owned |
| Size | About 16,500 employees and sales of about EUR 3.7 billion (2023, as reported by the company) |
| Product families | Proline flowmeters, Micropilot and Levelflex radar, Liquiphant switches, Cerabar and Deltabar pressure, iTEMP and iTHERM temperature, Liquiline and Memosens liquid analysis |
Milestones
- 1953: Georg H. Endress and Ludwig Hauser start the business in Lörrach on 1 February, first selling level meters.
- 1957: The Endress+Hauser name comes into use.
- 1975: The Endress family becomes sole shareholder.
- 2023: About 16,500 employees and sales of about EUR 3.7 billion, as reported by the company.
Endress+Hauser product lines
| Line | Measuring principle | Typical use |
|---|---|---|
| Promass F 300, Promass 80F, 83F/84F | Coriolis mass flow | Direct mass flow and density of liquids and gases, hydrocarbon transfer and chemical dosing |
| Promag P 300, P 500, H 300, W 400, W 10, 50P | Electromagnetic flow | Water, wastewater, slurries and other conductive liquids |
| Prowirl F 200, 72F | Vortex flow | Steam, gas and low-viscosity liquids |
| Prosonic Flow 92F, t-mass 65F | Ultrasonic and thermal mass flow | Water lines; compressed air and industrial gases |
| Micropilot FMR62, FMR67, FMR60, FMR10B, FMR20, FMR50, FMR52 | Free-space radar level, 80 GHz and 26 GHz | Tanks, process vessels, silos and open water channels |
| Levelflex FMP51, FMP50, FMP54, FMP55 | Guided wave radar level | Level and interface in vessels, separators and bypass chambers |
| Liquiphant FTL51, Prosonic S FMU90 | Vibronic point level; ultrasonic level | High and low level alarms, pump protection, open channel flow |
| Cerabar PMC71B, PMP51B, PMP71, Deltabar PMD78B, PMD75 | Pressure and differential pressure | Process pressure, hydrostatic level and DP flow |
| iTEMP TMT82, TMT162, iTHERM TM101, TR66, TR10 | Temperature transmitters and thermometers | RTD and thermocouple points with thermowells |
| Liquiline CM444, CM442, Memosens CPS11E, Stamolys reagents | Liquid analysis | pH, ORP, conductivity, dissolved oxygen and nutrient analysis in water treatment and process |
Where Endress+Hauser instruments are used
In Oman and the GCC, Endress+Hauser instruments are common in oil and gas production and processing, refineries and petrochemicals, desalination and water networks, wastewater treatment, power plants and food and beverage plants. Coriolis meters measure hydrocarbon and chemical flows, electromagnetic meters cover water and wastewater, radar transmitters handle tank and silo level, and Liquiline analysers monitor water quality. Proline 300 and 500 flowmeters include Heartbeat Technology for in-situ verification, which reduces the need to remove a meter for checks.
Ordering Endress+Hauser instruments: what we need
The order code on the nameplate (for example PMP71-1QA1S11RDADU) defines every option: measuring range, process connection, materials, output, approvals and display. Send it with the serial number; Endress+Hauser can retrieve the original configuration from the serial number. For a new instrument add the medium, operating and design pressure and temperature, range, line size or tank geometry, process connection, wetted materials, output or protocol (4-20 mA HART, PROFIBUS, FOUNDATION Fieldbus, Modbus) and the hazardous-area approval required. Older models such as Promass 80/83 or Micropilot M are replaced by current Proline or 80 GHz Micropilot devices.
Facts checked against Endress+Hauser company history and product information, October 2026.
Browse Endress+Hauser products by category: Flowmeters, Level Transmitter, Pressure Instrumentation, Temperature, Liquid Analysis Sensors, Liquid Analytical Systems.
FAQ
Questions about the Endress+Hauser FTL81 Liquiphant FailSafe Level
Answers from our engineering team on installation, compatibility and integration.
01What is the difference between FTL80 and FTL81?
Both are FailSafe Liquiphant switches with the same 4–20 mA electronics. The FTL80 is compact with a sensor length up to 80 mm, while the FTL81 has a short pipe or a pipe extension from 148 to 3,000 mm.
02What is the maximum probe length of the FTL81?
The datasheet gives a maximum sensor length of 3 m (10 ft), with a variable extension from 148 to 3,000 mm, and short pipe versions of 115 or 118 mm on G threads.
03Does the FTL81 need support for long probes?
The maximum lateral load of the pipe is 75 Nm. Where agitation or flow can load the pipe, a support is advised, and marine approval needs support on extensions longer than 1,600 mm.
04What viscosity can the FTL81 handle?
In maximum detection up to 10,000 mPa·s, in minimum detection up to 350 mPa·s, and in minimum detection at 230 to 280 °C up to 100 mPa·s.
05Which temperature range applies to the FTL81?
The process range is –50 to +150 °C or –60 to +280 °C, with 300 °C allowed for up to 50 hours cumulative. Liquefied gas applications are limited to –50 to +60 °C.
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