Endress+Hauser FTI52 Liquicap M Rope Capacitance Level Switch

Name: Endress+Hauser FTI52 Liquicap M Rope Level Switch | Oman
Brand: Endress+Hauser (E & H)
SKU: FTI52

Description

FTI52 Liquicap M rope-probe capacitance level switch

The Endress+Hauser FTI52 is the rope-probe member of the Liquicap M family of capacitance point level switches for liquids. Where its sibling FTI51 uses a rigid rod, the FTI52 hangs a flexible insulated stainless rope from the process connection and ends it in a tensioning weight, so a single switch can be installed in a tall tank, a deep sump or a vessel with limited headroom for a long rod. Seven Star LLC supplies the FTI52 in Oman and the GCC as an independent supplier in Muscat.

Like all Liquicap M instruments, the FTI52 is configured to order. Rope length, insulation, process connection, housing and electronic insert are selected in the manufacturer’s configurator, which generates the order code. The datasheet does not print a decodable code table, so this page describes the options and leaves the code to be confirmed against your duty.

FTI52 technical specifications

Parameter	Specification
Manufacturer / part number	Endress+Hauser / FTI52 (Liquicap M point level switch, rope probe)
Measuring principle	Capacitive point level detection in liquids
Process temperature	–80 to +200 °C (–112 to +392 °F)
Process pressure	–1 to 25 or –1 to 100 bar (63 bar with an uninsulated inactive length), –1 to 50 bar with a fully insulated inactive length
Probe rope	316 (1.4401) stainless rope, 4 mm diameter, insulation 0.75 mm
Rope insulation	FEP or PFA
Total / active rope length	420 to 10,000 mm (16.5 to 394 in) in the fully insulated version
Tensioning weight	22 mm diameter, 120 mm long, with a 5 mm anchor hole
Tensile load capacity at 20 °C	200 N
Rope weight	0.04 kg/m
Ambient temperature (housing)	–50 to +70 °C, –40 °C minimum for F16 polyester; separate housing to +120 °C
Capacitance span	ΔC = 5 to 1,600 pF; probe base capacitance approximately 18 pF
Wetted materials	316 rope and tensioning parts, 316L process connection, FEP/PFA insulation, asbestos-free seals
Separate housing	Cable up to 6 m; cable plus rope not above 10 m

How the FTI52 rope probe measures

The insulated rope and the grounded tank wall form a capacitor. In air the capacitance is low; as the liquid climbs the rope the capacitance rises, at approximately 19 pF per 100 mm for the insulated rope in water compared with about 1 pF per 100 mm in air. The electronic insert watches for the calibrated switching capacitance and changes its output when the liquid reaches the set height. Because the rope is thin, the change per metre is smaller than with a 16 mm rod, which is why the manufacturer asks for sufficient conductivity or a metallic reference.

Interface detection between a non-conductive and a conductive liquid, and detection of foam on conductive liquids, are listed for the Liquicap M family, with the same adjustment procedure as the FTI51. An optional inactive length keeps the rope insulated and electrically passive near the nozzle, so condensate and deposits in the connection do not move the switch point, and the FTI52 can then be used where there is a mounting nozzle.

Installing the FTI52 rope probe correctly

A rope probe behaves differently from a rod and the installation rules follow from that:

Swinging changes the switch point. The rope must be tightened or anchored, using the thread in the tensioning weight, so that it cannot move with the liquid.
Do not tension excessively. Guy the end with a spring or leave the rope slightly loose; the maximum tensile load is 200 N.
Media below 1 mS/cm need extra measures such as a metallic reference or a metal tank, because the rope capacitance is small.
The FTI52 is not suited to agitator tanks, high-viscosity liquids or plastic tanks according to the datasheet.
Both rope versions can be shortened on site after the weight is removed, which simplifies stocking one spare length.

Keep the rope away from the filling curtain, at least 10 mm from the tank floor, and 500 mm from neighbouring probes. After commissioning, calibrate empty and full with the electronic insert push-button.

Electronic inserts and outputs

Electronic insert	Typical use with the FTI52
FEI51 / FEI52 / FEI54	Direct switching: AC thyristor, DC PNP transistor, or relay with two changeover contacts, calibrated by push-button
FEI53 / FEI57S	Signal to a separate Nivotester, with self-test from the switching unit
FEI55	Two-wire 8/16 mA, SIL2 hardware and SIL3 software approval
FEI58	NAMUR two-wire signal to a separate switching unit

The insert is replaceable without recalibration, and switching delay can be set between 0.3 and 10 s where the insert supports it. Minimum or maximum safety is selected to suit dry-run or overfill protection.

Selecting the FTI52: checklist

Tank depth and the switch height measured from the sealing surface; confirm the rope length is within 420 to 10,000 mm.
Whether the tank is metallic, and the liquid conductivity, since rope probes need a suitable counter electrode.
Whether the rope can be anchored without touching internals.
Process temperature, pressure and connection rating, with the lowest limit of the device and the flange governing.
Need for an inactive length (nozzle mounting) and its insulation.
Output and supply: AC, PNP, relay, 8/16 mA SIL, PFM or NAMUR.
Zone classification and approvals for the ordered version.

Maintenance and spares for the FTI52

The FTI52 has no moving parts, so routine work is visual: check the rope insulation for cuts, check the anchor and the tension, and clean any coating. A damaged insulation layer allows leakage current and invalidates the calibration. Keep a spare electronic insert and a spare tensioning weight for tanks where the FTI52 is installed in numbers. Surge arresters and a protective cover are listed accessories for outdoor tanks.

Applications for the FTI52 in Oman and the GCC

Deep storage and process tanks are common on Omani sites: desalination brine and chemical tanks, water treatment clarifiers, fuel and diesel storage, produced-water holding vessels and waste sumps. The FTI52 suits a vertical tank where a long rigid rod would be impractical to install through a roof nozzle, and its rope can be shortened to fit if the tank height differs from the drawing. Heat and humidity make a protective cover and sealed cable glands worthwhile.

Rod versus rope within the Liquicap M range

Probe	Better suited to
Rigid rod (FTI51)	Agitated tanks, viscous liquids, plastic tanks, rod up to about 4 m for pump control
Rope (FTI52)	Tall tanks, long active length, installation through limited headroom, not for agitators or viscous media

Information to send with an RFQ for the FTI52

Liquid, conductivity and any foam or interface requirement
Tank height, nozzle size and the distance of the switch point from the nozzle
Temperature and pressure range and tank material
Required rope length and whether an inactive length is needed
Output type, supply voltage and the receiving PLC or switching unit
Hazardous area zone and approvals
Quantity and delivery location

Documents and quotation

The datasheet for the FTI52 is attached on this page. It is the manufacturer’s Technical Information with rope dimensions, derating curves and insert specifications.

Send the part number FTI52 together with your tank and process data and we will confirm availability and lead time for Oman and the GCC.

Datasheets & Documents

Datasheet Endress+Hauser FTI52 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 FTI52 Liquicap M Rope Capacitance

Answers from our engineering team on installation, compatibility and integration.

01What is the difference between the FTI52 and FTI51?

Both are Liquicap M capacitance switches. The FTI52 uses a flexible insulated 4 mm rope with a tensioning weight and can be up to 10 m long, while the FTI51 uses a rigid rod.

02What tensile load can the FTI52 rope take?

The datasheet gives a tensile load capacity of 200 N at 20 °C. The rope should be loose or guyed with a spring rather than tightened hard.

03Can the FTI52 be used in a tank with an agitator?

No. The datasheet states that fully insulated rope probes are not suitable for agitator tanks, high-viscosity liquids or plastic tanks.

04What is the temperature range of the FTI52?

Process temperature is –80 to +200 °C. Housing ambient temperature is –50 to +70 °C, with –40 °C minimum for the polyester housing.

05Can the rope length be adjusted on site?

Yes. After removing the weight, both rope versions can be shortened according to the operating instructions, and the switch point is then recalibrated.