FS-550(E) – Paddle Flow Switch

For Flow/No-Flow Detection in Large Line Sizes

The FS-550(E) paddle flow switch has been engineered for positive liquid flow detection at pressures up to 2000 psig (138 bar).

Unique, patented cam design assures low pressure drop and does not require bellows, seals, or mechanical linkages.

Minimum in-line restriction; paddle pivots to move out of liquid path.


Typical Applications:

Assure flow and/or leak detection in large, high pressure lines in:

Compressors • Heat Exchangers • Turbines • Engines • Boilers • Chillers

Protect high or low pressure pumps from cavitation, sense critical reverse flow and protect:

Valves • Pumps • Regulators



When the magnetic field of permanent magnet inside the shuttle or piston is moved into the proximity of the reed switch inside the stationary stem, the reed switch contacts “snap” together and closes the electrical circuit. When the magnetic field is moved away from the reed switch, the reed switch contacts move apart and the circuit is opened.


Request a Quote
Max. flow
determined by the pipe’s inside diameter
Set points
see set point adjustment guideline
Switching function
IP 65
Brass or Stainless steel