FSW40-50-Series

Supported Applications

The Omega FSW-40A and FSW-50 Series are industrial flow switches designed for in-line monitoring of liquid flow. The series is engineered for use with machine-cutting oils, sewage applications, highly particle-contaminated liquids such as medium slurries, and mildly corrosive liquids including low to medium concentration acids and bases, sea water, sewage oils, and rusty coolant water.

The FSW-50 Series special construction models are specified for concentrated corrosive liquids, including sulfuric, nitric, hydrochloric, and acetic acids; aqueous ammonia; benzene; and magnesium chloride. These switches respond to flow only, independent of line pressure, temperature, and environment, signaling conditions such as pump failure, valve malfunction, or pipe clogging.

Operating Conditions & Performance

The series covers a switch point adjustment range from 2.0 to 15 ft/s depending on the model and configuration. The FSW-40A Series operates at up to 300 psig @ 82°C (180°F), while the FSW-50 Series is rated for 100 psig @ 93°C (200°F). A minimum operating temperature of 4°C (40°F) applies across the series.

Performance characteristics include a nominal sensitivity of 10% flow change to activate at the upper end of range and 30% at the lower end. Pressure drop is less than 1 psi for 1" to 3" pipe sizes and negligible for 4" and above. The switches feature an SPDT relay rated at 15 A @ 125 or 250 Vac with a median life of 10,000,000 operations.

Configuration Options

The series offers configurable switch points via internal screw adjustment and multiple drag disks for incremental tuning. Models are available in various sizes to accommodate pipe diameters from 1" up to 48", with specific models designated for different ranges:

• FSW-40A/41A/42A/43A Series: Brass and stainless steel construction; suitable for pipes ranging from 1" to 48".
• FSW-50/51/52 Series: Plastic (PPS*) / 316 SS construction with a flexible filter boot for particle contamination resistance; available in special PPS*, Hastelloy C, and Viton construction for corrosive service.

Process connections include 1" NPT or 1¼" NPT fittings. Electrical connection is provided via a water-resistant strain relief cable connector compatible with diameters of .250" ±0.025" (or .250" ±0.25"). The series includes CE and RoHS certifications.

Key Product Differences

The FSW-40A Series utilizes brass, 316 SS, phosphor bronze, EPDM, and cork rubber wetted materials, with a special construction option (suffix "-SS") available using 316 SS, FKM, and PTFE. The FSW-50 Series standard construction uses polyphenylene sulfide, 316 SS, and Viton; the special construction model adds Hastelloy C.

Physical dimensions vary by series: FSW-40A/41A units measure 38 mm (1.5 in), while FSW-50 units are more compact at 29 mm (1.2 in). The FSW-40A Series weighs approximately 1.59 kg (3.5 lb) compared to the lighter FSW-50 Series weight of 179 g (6 oz).