G-4
FLOW SWITCHES
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Housing
and Piston
Material
Flow
Setting
GPM
Part Numbers
SPST Switch With
SPDT Switch
N.O., No Flow N.C., No Flow
Ryton®
0.1 122340 122346 122352
0.25 122341 122347 122353
0.5 122342 122348 122354
0.75 122343 122349 122355
1.0 122344 122350 122356
1.5 122345 122351 122357
Material Adapter Size Part Numbers
Ryton®1/8˝ NPT* 123028
1/4˝ NPT* 123029
Polypropylene 1/4˝ NPT* 158602
1/2˝ Barb** 158603
.586
15
1.00
25
3.640
92
3.80
97
1.255
32
LEADWIRES
9/16˝ -18 UNF-2B THREAD
WITH O RING SEAL PORT
.920 DIA
23
1.90
48
2.0
1.5
1.0
0.5
00 0.5 1.0 1.5 2.0
3.0
2.5
FLOW RATE - GPM
PRESSURE DROP (PSID)
Part No. 122355
Part No. 122357
Part No. 122352
Tests conducted with units in vertical position (lead wires up) with water
at +70 F (21 C).
1" (25.4 mm)
DIA.
.87 FLAT
5/8"
(15.9 mm)
1/2"
(12.7 mm)
1/4" NPT
3/4" (19.0 mm) DIA.
.62 FLAT
1/2" (12.7 mm)
3/8" (9.5 mm)
.54" (13.7 mm)
DIA.
1/2" (12.7 mm)
DIA.
3/4" (19.0 mm)
HEX 1"
(25.4 mm)
.25"
(6.3 mm)
1/2" Barb
1/8" NPT
FS-4 Series –
Low Cost, Molded Plastic Construction
Flow Rate Settings: 0.1 GPM to 1.5 GPM
Port Size: 9/16˝-18 UNF
Primary Construction Material: Ryton®
Setting Type: Fixed
The FS-4 Series makes flow protection economical for a broad range of industrial
applications such as welders, lubrication systems, medical sterilizers and laundry
chemicals dispensing.
Specifications
Wetted Materials
Housing and Piston Ryton® R4
Spring 316 Stainless Steel
O-Ring Viton®
Other Wetted Parts Epoxy
Operating Pressure, Maximum 250 PSIG (17.2 bar) @ 70°F (21°C)
Operating Temperature 0°F to 225°F (-17°C to +107°C)
Set Point Accuracy ±15% Maximum
Set Point Differential 20% Maximum
Switch* SPST or SPDT, 20 VA (SPDT: 240 VAC Max.)
Inlet/Outlet Ports 9/16˝ -18 UNF-2B Thread
Recommended Filtration 50 Microns or Better
Electrical Termination
SPST 18 AWG, Zipcord, 24˝ Long
SPDT 18 AWG, PVC 24˝ Long Leads
* See “Electrical Data” on Page X-5 for more information.
How To Order – Standard Models
Note:
Flow settings are calibrated using water @ +70°F on increasing flow, with units in a vertical position
(lead wires up).
Port Adapters for FS-4
Converts 9/16˝ threaded ports to NPT or barbed connection. Made of Ryton®-R4 or
polypropylene with O-Rings in place.
CAUTION: Do not exceed 15 in./lbs. maximum torque when installing adapter fittings.
*Wrench flats provide for proper
assembly.
**Accepts 1/2˝ I.D. flexible hose
– Stock Items.
U.L. Recognized —
File No. E31926
CSA Listed —
File No. LR30200
Dimensions
inch
mm
Pressure Drop – Typical
