FSW-91-R Liquid Flow Transmitter & Switch w/Visual Indication

 Supported Applications

The Omega FSW-9000 Series comprises liquid flow transmitters, sensors, and switches designed for measurement and control applications. The series measures liquid flow velocity in pipes using a conical sensor tip that allows installation at almost any angle without affecting accuracy. Configurations include the compact FSW-9000 transmitter with visual indication, the separate-sensor FSW-91-R model suitable for very small pipes (e.g., 3/8" or 9.5 mm), and remote control options via the FSCN-91 relay.

Operating Conditions & Performance

The series operates within a process temperature range of -20 to 80°C (-4 to 176°F). A sanitary option extends this capability to 284°F for CIP applications. Ambient operating temperatures are rated from -20 to 60°C (-4 to 140°F). The maximum working pressure is specified as 300 bar (4,500 PSI) in the manual and 300 bar (4351 psi) in the data sheet table. Flow velocity measurement ranges cover 0.04 m/s to 2.0 m/s for water.

Performance specifications include an accuracy of ±5% of setpoint and repeatability of ±1% of setpoint. The device features a nominal response time of 3 to 10 seconds with a maximum start-up delay of 12 seconds. Wetted materials are constructed from 316 Stainless Steel, and the series can be coated for aggressive mediums by adding an "-ETFE" suffix.

Configuration Options

The FSW-9000 Series offers configurable process connections, enclosure types, insertion lengths, and output signals to accommodate diverse installation requirements. The electronics utilize microprocessor-based design with self-calibration for temperature compensation.

• Process Connections: Available in ½ NPT thread, ¾ NPT thread, 1 NPT thread, 1.5" Tri-Grip™ (inches only), and 2" ANSI flange, 150# 316 SS.
• Enclosures: Standard glass-filled nylon with ½ NPT conduit, cable gland, and 2 m (6.5') cable; optional aluminum die cast enclosure available for hazardous environments or specific mounting needs.
• Insertion Lengths: Standard options include 35 mm (1⅜"), 50 mm (2"), and 75 mm (3"). Custom lengths are available upon consultation with Flow Engineering.
• Output Signals: Options include analog 4 to 20 mA, PNP/NPN transistor output (up to 400 mA), or Relay (SPDT) for the FSW-91-R + FSCN-90 configuration.
• Visual Indication: Features an 8 LED bargraph for flow rate and setpoint status, plus a di-chromatic switch point status indicator (Red: No flow; Green: Flow).

Key Product Differences

The series distinguishes between integrated transmitters and separate sensor configurations. The FSW-9000 is an enclosed unit with glass-filled nylon or aluminum housing, providing both analog 4 to 20 mA output and PNP/NPN switch output powered by 24 Vdc ±10%. In contrast, the FSW-91-R variant consists of a sensor without an enclosed housing, intended for remote control via separate electronics such as the FSCN-91 relay. The FSCN-91 operates on either DC or AC supply voltage (85 to 240 Vac, 50/60 Hz or 24 Vdc ±10%) and provides analog 4 to 20 mA and SPDT outputs within an ABS enclosure suitable for DIN rail mounting.

Model numbering follows the pattern FSW-9(**)(**)(**) where digits specify process connection, enclosure type, and insertion length. For example, model FSW-9123 denotes a transmitter with ½ NPT thread, aluminum die cast enclosure, and 75 mm (3") insertion length.