Datasheet

FLOW SWITCHES
52
FLOW
SWITCHES
www.gems-sensors.co.uk
PISTON TYPE
FS-3 0.2 - 3.8 (l/min) pre-adjusted set points
0 2.0 4.0 6.0 8.0
Flow rate (l/min)
0.138
0.104
0.069
0.035
0
Pressure drop (bar)
These ultra compact switches have been specially designed for reliable operation in clean-
post-filtered water. They are made primarily of Noryl®, with all other wetted materials are
FDA or NSF compliant. FS-3 switches are instrument quality, yet affordably priced for pure
water equipment from UV lamp switching to filter life monitoring. Also well suited to some
chemical applications and a variety of cooling applications: lasers, welders, etc.
Operating pressure 10 bar at 20°C; 3.4 bar at 100°C
Operating temperature max. 100°C
Switch SPST, NO, 20 VA, 120...240 V AC/DC
Inlet / outlet ports 1/4” NPT, R 1/4”
Electrical connection AWG 22 PVC-lead wires, Length appr. 0.3m
Mounting orientation Any position
Approvals U.L. approved file No. E91926
Specifications (all data related to water at +20°C)
*Materials of construction are either FDA or NSF compliant.
Notes:
1. NO switches in No Flow condition are standard; please contact us for NC models.
2. The device is designed to provide Flow/No Flow sensing. Tabulated set points specify maximum
contact closure thresholds on increasing fluid flow. Re-establishment of a Normally Open contact
occurs on decreasing fluid flow between set point and no flow.
3. Flow settings are based on a vertical position (inlet port down), using water at +20°C on increasing
flow. Some variation in set point actuation will occur in other mounting orientations.
4. Use of 50 micron, or better, filtration is required.
5. Not recommended for use with oils.
How to Order
Dimensions (in mm)
Pressure Drop Diagram
GAS/AIR
Set Points (l/min)(air) Order numbers for Gases
0.35 bar 6.9bar 1/4” NPT R1/4
12 28 165840-AIR 166701-AIR
28 74 165841-AIR 166702-AIR
70 158 165842-AIR 166703-AIR
140 340 165843-AIR 166704-AIR
Set points (Fluid) Order numbers for Fluid
(l/min) 1/4” NPT R 1/4”
0.2 165840
166701
1.0 165841 166702
2.0 165842 166703
3.8 165843 166704
Standard Models (Medium: water)
Specify the FS-3 flow switch using part numbers tabulated column above.
Special Requirements
GEMS caters to OEM needs with special configurations, including Gas (Air) flow and customer specified
electrical terminations.
Housing: Noryl
®
Piston: Noryl
®
Spring: Stainless Steel
25.4
12.7
104
1/4” NPT or
R 1/4”
Standard Products in bold
FLOW ➔