reed contact (3)
magnet (2)
magnet (4)
paddle system (1)
shaft
N
S
N
S
flow
LOW COST FLOW SWITCHES
FSW300 Series
Starts at
$
150
⻬ Adjustable Switch Point
⻬ Low Pressure Drop
⻬ Economical
⻬ Field Installation
for 1⁄2 to 8" Pipes
⻬ Instant Response
⻬ High Repeatability
The FSW301 flow switch comprises
a paddle system (1) with a permanent
magnet attached (2). Above that
magnet is a reed contact (3), located
outside the flow of fluid. A second
magnet with opposing poles (4) creates
the force necessary to reset the switch
back to the no flow position.
When the monitored flow pushes the
paddle and changes the position of
the magnet (2) in relation to the reed
contact (3) it activates the contact.
As soon as the flow is interrupted,
the paddle moves back to its starting
position, which returns the reed
contact to the initial position. The force
necessary to push the magnet back is
provided by the two magnets repelling
each other. Using magnetic force
instead of the usual leaf spring means
the switch is considerably more stable
in the long term and much less
sensitive to pressure peaks.
The reed
contact used
as a sensing
element
consists of two
ferro-magnetic
contact blades
located in a
glass bulb filled
with inert gas.
This practically
eliminates wear
resulting from
contact burning.
This construction
allows a useful life
of up to 100,000,000
switching cycles.
COMMON
SPECIFICATIONS
Max Pressure: 25 bar
(365 psi)
Max Process Temp:
110°C (230°F)
Max Ambient Temp:
80°C (176°F)
Protection Class: IP65
Connection:
Materials of Construction:
Body: Brass
Paddle System:
Polypropylene, Noryl
Shaft: Stainless steel
1
⁄2-14 NPT
®
FSW301, $164,
shown actual size.
Field trimmable to
size. Shown
smaller than
actual size.
FSW301
Pipe Size Setpoint Range
mm (in) LPM (GPM)
3
19.0 (
) 15 (4.0) to 18 (4.7)
⁄
4
25.4 (1) 17 (5.0) to 22 (5.7)
31.75 (1
38.1 (1
63.5 (2
1
) 27 (7.0) to 32 (8.4)
⁄
4
1
) 30 (8.0) to 35 (9.3)
⁄
2
50.8 (2) 40 (11) to 45 (11.9)
1
) 80 (21) to 85 (22.5)
⁄
2
101.6 (4) 97 (26) to 107 (28.2)
152.4 (6) 238 (63) to 258 (68.2)
203.2 (8) 485 (128) to 500 (132)
Insertion Type Switch
To Order (Specify Model Number)
Model No. Price Description
FSW301 $164 Flow switch, insertion style,
70A-2 24 Fast pulse tone audible alarm
Comes complete with operator's manual.
Ordering Example: FSW301, insertion style flow switch and 70A-2, fast pulse tone
alarm, $164 + 24 = $188.
Recommended Reference Book: Instrumentation Control Systems,
FW-336, $66. Visit omega.com/bobi for Additional Books
B-75
AVAILABLE FOR FAST DELIVERY!
1
male NPT
⁄
2
SPECIFICATIONS
FSW301
Max Switching Current: 1 A
Max Switching Voltage:
230 Vac, 48 Vdc
Maximum Rating: 26 VA, 20 W
Set Point Tolerance: ±15%
Plug Connector: DIN 43650
form A/ISO 4400 cable socket
with terminal screws, suitable
for outer cable diameter 4.57
to 6.85 mm (0.18 to 0.27")
Dimensions (Excluding
Paddle or Tee):
114 x 38 x 89 mm
(4.5 x 1.5 x 3.5")
SPECIFICATIONS
FSW302, 303, 304
Max Pressure: 25 bar (362 psi)
Max Process Temp: 110°C (230°F)
Max Ambient Temp: 80°C (176°F)
Material of Construction: Brass body, pipe
section and paddle system
FSW304, $186,
shown smaller
than actual size.
AVAILABLE FOR FAST DELIVERY!
To Order (Specify Model Number)
Model No. Price Description Setpoint Range LPM (GPM)
FSW302 $186 Flow switch, inline
FSW303 186 Flow switch, inline
FSW304 186 Flow switch, inline 1", brass tee 13.2 to 16.7 (3.5 to 4.4)
Comes complete with operator’s manual.
Ordering Example: FSW303, inline flow switch,
3
" brass NPT connection, 70A-2, audible alarm, $186 + 24 = $210.
⁄
4
1
", brass tee 3.4 to 4.2 (0.9 to 1.1)
⁄
2
3
", brass tee 6.8 to 9.1 (1.8 to 2.4)
⁄
4
B
SPECIFICATIONS
FSW305, 306, 307
Max Pressure: 10 bar (145 psi)
Max Process Temp: 60°C (140°F)
Max Ambient Temp: 60°C (140°F)
Materials of Construction:
FSW307, $150,
shown smaller
than actual size.
Pipe Section: PVC
Body: Polypropylene, Noryl
®
Paddle System: Polypropylene, Noryl
AVAILABLE FOR FAST DELIVERY!
To Order (Specify Model Number)
Model No. Price Description Setpoint Range LPM (GPM)
FSW305 $150 Flow switch inline
FSW306 150 Flow switch inline
FSW307 150 Flow switch inline 1" PVC tee 10.6 to 14.8 (2.8 to 3.9)
Comes complete with operator’s manual.
Ordering Example: FSW305, inline flow switch,
$150 + 24 = $174.
B-76
1
" PVC tee 4.9 to 6.8 (1.3 to 1.8)
⁄
2
3
" PVC tee 9.5 to 12.1 (2.5 to 3.2)
⁄
4
1
" PVC tee connection, 70A-2, audible alarm,
⁄
2