The FCI FLT93B Basic insertion‑type FlexSwitch represents a major technological breakthrough in thermal technology. It is easily field‑configured, providing flexibility, accuracy and stability for flow and temperature switching applications. FCI is the only thermal manufacturer to provide temperature compensation ensuring setpoint accuracy for process temperatures that vary up to ±100 °F (±55 °C).

Setpoint Ranges and Accuracy

The switch supports setpoint ranges for water‑based liquids (0.01–3.0 fps), hydrocarbon‑based liquids (0.01–5.0 fps) and air/gas (0.25–120 sfps). Accuracy is ±0.5% of reading or better, with repeatability of ±0.5% of reading. Response time can be as low as 3 seconds. An optional temperature output is also available.

Construction and Installation

The FLT93B is housed in a robust, insertion‑style probe that can be mounted through a compression fitting, threaded or flanged connection. It is suitable for pump protection, cooling water / heat exchangers, drain line flow, safety spray nozzle monitoring, oil well system testing, and relief valve monitoring.

Safety Certifications

The switch complies with NFPA Code 30 for storage and use of flammable liquids, with a SIL 2 rating for Safety Instrumented Systems (SIS). Optional N.I.S.T. flow calibration services are available for customer‑specified setpoints or flow curves.

Applications

The FLT93B is ideal for pump protection (dry‑run prevention), cooling water and heat exchanger monitoring, drain line flow detection, safety spray nozzle flow verification, oil well system testing, and relief valve monitoring. It is widely used in chemical processing, oil & gas, power generation and industrial automation.