FSW30-Series

Supported Applications

The Omega FSW30-Series comprises non-magnetic industrial flow switches designed for in-line fluid monitoring. These rugged units respond to fluid flow and are explicitly noted as ideal for rusty water applications. The series is suitable for use with pure water, tap water, filtered sewage water, alcohols, oils, gasolines, glycols, and soap solutions.

Important safety notes from the documentation state that these units are not compatible with gasoline without proper precautions (such as intrinsic safety relays) if used with flammable liquids. Additionally, the products are not designed for patient-connected applications.

Operating Conditions & Performance

The FSW30-Series operates within a temperature range of 4°C (40°F) to 82°C (180°F). The maximum continuous working line pressure is rated at 300 psig @ 82°C (180°F), with units proof tested to 1200 PSIG @ 180°F. Flow ranges are water-calibrated and vary by model configuration:

• FSW-30A: 0.12 to 8 GPM
• FSW-31A (with Drag Disk #2): 6 to 20 GPM; with Drag Disk #3: 15 to 35 GPM; with Drag Disk #4: 25 to 70 GPM
• FSW-32A: 4 to 8 GPM (fixed range)

Sensitivity is defined as a 5% flow change at the upper end of the range and 25% at the lower end required to activate the switch. Pressure drop across the unit varies by model: FSW-30A ranges from 1 to 5 psi; FSW-31A and FSW-32A (4 to 8 GPM range) show a differential of 2 to 15 psi, while other ranges are less than 2 psi.

Configuration Options

The series offers configurable flow detection via interchangeable drag disks for the FSW-31A model and fixed orifices for specific models. The switches feature a brass body with an aluminum cover (per manual) or Noryl cover (per data sheet), stainless steel, and plastic hardware.

Electrical Outputs

• Standard: SPDT 15 A @ 125 or 250 Vac relay switch with a median life of 10,000,000 operations. The switch may be overloaded to 20 amps @ 125 or 250 Vac for a minimum of 20,000 operations.
• Option 'D': Dual SPDT relays providing DPDT action with a nominal differential flow between actuation points of 5%.

Mechanical & Installation Features

• Process Connection: NPT threaded to pipe directly in-line (½" FNPT for FSW-30A; 1" FNPT for FSW-31A and FSW-32A).
• Mounting: Designed to be mounted in any position.
• Electrical Connection: Easy screw terminal wiring requiring no soldering, with a water-resistant cable fitting for diameters of .250" ±.025" (optional connector cables available).

Wetted Materials

Materials in contact with the fluid include red brass, 316 SS or 302-304 stainless steel, phosphor bronze, Noryl, EPDM, and PVC (specifically for Models FSW-31A and 32A). Buna-N is also listed as a wetted material in manual documentation.

Key Product Differences

The series distinguishes between three primary model numbers based on flow range and connection size:

• FSW-30A: A ½" FNPT unit covering the low-flow range of 0.12 to 8 GPM, supplied with six orifices.
• FSW-31A: A 1" FNPT unit offering a wide adjustable range from 6 to 70 GPM by changing drag disks (Disks #2, #3, and #4 are provided).
• FSW-32A: A 1" FNPT unit with a fixed flow range of 4 to 8 GPM using Drag Disk #1.

All models share the same electrical enclosure dimensions (approximately 5.63 x 4.94 inches) and weight (3.5 lb). The FSW-30A is noted as having orifices slightly smaller than actual size in illustrations, while drag disks for other models can be changed while the switch is in-line but not during operation.