Endress+Hauser FMM50 Silopilot Electromechanical Level

Endress+Hauser FMM50 Silopilot electromechanical level system for silos and bunkers

The Endress+Hauser FMM50 Silopilot is an electromechanical level measuring system that lowers a sensing weight on a measuring tape until it touches the product, then reads the tape length and reports the level. It is designed for bunkers and silos with powdered, fine-grained or coarse bulk solids, and it can also be used in vessels with liquids. Because it relies on mechanical contact and a pulse count rather than reflection of a signal, it keeps working where dust, steam, build-up or very tall vessels defeat ultrasonic and radar instruments. Seven Star LLC supplies FMM50 units in Oman and the GCC as an independent supplier in Muscat.

The FMM50 reaches measuring ranges of up to 90 m with a stated resolution of ±5 cm or ±1 pulse, independent of the selected range.

Reading the FMM50 configuration

• Power supply: 180 to 253 VAC or 90 to 127 VAC options.
• Process temperature: options for –20 to +70 °C, up to +150 °C or up to +230 °C.
• Process pressure: 0.8 to 1.1 bar abs or 0.8 to 3.0 bar abs.
• Sensing weight: normal, umbrella, bag, cage, bell or oval float variants.
• Ambient and heater: versions with or without self-regulating heater.
• Relay outputs: 2 as standard, 6 as an option.

FMM50 technical specifications

How the FMM50 measures

When a measurement starts, either manually or on a timer, the motor lowers the sensing weight and the measuring tape runs over a counting wheel that sends a pulse to the electronics every 5 cm. When the weight touches the product, the motor, which is freely suspended, tilts out of its working position, and the electronics stop the drive. The weight is then pulled back up to its top position and the cycle ends. The result appears on the display, on the 4–20 mA output and through relays.

During the whole cycle the relay outputs can emit counter pulses, a measuring flag that locks a filling system while the weight is down, a top-position signal, an alarm and a service-interval signal. A linearization table of up to 32 reference points converts level into volume or mass. Since a measurement takes at least one minute, and the datasheet recommends not going below five minutes even for short ranges, the FMM50 suits slow-changing silo inventories, not fast process control.

Sensing weights and what they are for

FMM50 selection and ordering checklist

• Vessel height and empty/full distances, to confirm range up to 90 m.
• Bulk material and its density, particle size, dustiness and temperature, to pick the sensing weight.
• Process temperature option and nozzle length: the datasheet recommends a nozzle of at least 500 mm up to 150 °C and 1,000 mm up to 230 °C.
• Process pressure option and the wiper length that matches the nozzle height (225, 515 or 1,015 mm).
• Supply voltage, relay count and need for an external start button.
• Cold-weather heater if ambient falls below 0 °C.
• Hazardous-area requirements; explosion protection data is in separate Ex documentation.

Installation, commissioning and maintenance of the FMM50

Mount the FMM50 on a horizontal DN100 PN16 counter flange (maximum tilt 2 degrees) on the silo roof, away from inflow cones, cornices and structure that could damage the tape. Use weather protection outdoors with at least 400 mm free height above. In dusty silos, connect a slight air purge to the G1/4 connection on the flange. Keep the device away from vibration, which can falsely trigger the tape switch.

Commissioning is menu-driven from the four-line display: set empty and full calibration, block distance and safety distances. The device stores parameters when power is lost and lists current and previous errors with help text. Wearing parts are the measuring tape, sensing weight and chain, so schedule inspection and keep a spare sensing weight, especially for silos with a mill or screw below.

Typical FMM50 applications in Oman and the GCC

Common uses in Oman and the GCC include cement and clinker silos, fly ash, lime, sand and aggregate bunkers, grain and feed silos, coal stockyards and bulk chemical storage. Heavy dust, high temperature and very tall silos are where a mechanical system is chosen over radar. Dust-tight IP67, an optional heater and sensing weights up to +230 °C cover the Gulf climate and process conditions.

Information to send with an FMM50 RFQ

• Silo height, diameter, roof nozzle size and flange.
• Product, bulk density and particle size.
• Process temperature and pressure.
• Power supply and number of relays or inputs.
• Hazardous-area classification (dust or gas).
• Preferred sensing weight, if known.

Documents and quotation

The official Technical Information for the Silopilot FMM50 (TI00395F) is attached on this page as a datasheet.

Send the FMM50 requirements above and Seven Star LLC will prepare a quotation for Oman and the GCC.