Swagelok® Vertical Flow Sensors—FV4 Series
Swagelok vertical flow sensors sense increasing or decreasing flow in gas systems and actuate an electrical switch at a predetermined flow range.

Specifications Flow Sensor Working Pressure Temperature Range Body Material End Connections • Types • Sizes Reed Switch

Up to 5000 psig (344 bar) –40 to 175°F (–40 to 79°C) 316L stainless steel Swagelok tube fittings, VCR metal gasket face seal fittings, tube extensions 1/4 in. and 6 mm Single-pole, double-throw, 3-wire/2-position

More Information
Download the Vertical Flow Sensors—FV4 Series catalog.
Contact your authorized Swagelok sales and service representative.

Operation
The Swagelok FV4 series flow sensor contains a float with a calibrated orifice that moves up or down in the float guide as flow increases or decreases. A magnet encased in the float above the orifice alternates electrical continuity between the black and the red leads of the adjacent reed switch.

Features

• Models can be selected to sense either increasing flow or decreasing flow.
• Snap-action float provides positive actuation.
• All-welded construction ensures fluid containment.
• High-strength, permanent magnet and 316L SS materials enhance durability.
• Replaceable switch assembly outside flow path eases maintenance.

Testing
Every FV4 series flow sensor is tested for proper operation and is helium leak tested at the envelope to a maximum leak rate of 4 × 10^–9 std cm³/s.

Cleaning and Packaging
All FV4 series flow sensors are are processed in accordance with Swagelok Special Cleaning and Packaging (SC-11) to ensure compliance with product cleanliness requirements stated in ASTM G93 Level C.

Installation
The FV4 series flow sensor must be installed in a vertical orientation with the arrow pointing up.

Accessories
Replacement reed switch kit includes switch assembly, retaining ring, assembly tool, and instructions.