G-14
FLOW SWITCHES
Visit www.GemsSensors.com for most current information. FS-10798 Series / p1of2 / 30-JUL-14
UL Approved
Explosion-Proof
SWITCH-FLOW
MAX IN
MIN
OUT
MFRS. P/N
SPEC.
MFRS. S/N
TYPE NO.
CONTR. NO.
STOCK NO.
4-1/8"
(104.7 mm)
2"
(50.8 mm)
3/4"
(19.0 mm)
5/8"
(15.8 mm)
1-1/4"
(31.7 mm) 1/2" NPT BOTH PORTS
FLOW ACTUATION ADJUSTMENT
1-1/16"
(26.9 mm)
MAX.
1/2"
(12.7 mm)
IN
G
E
M
S
C
O
M
P
L
I
A
N
T
®
Ro H S
G
E
M
S
C
O
M
P
L
I
A
N
T
®
RoHS
FS-10798 Series – Externally Adjustable for
Water, Oils and Gases
Flow Rate Settings: Liquids: Infinite Adjustment between 0.5 GPM and
20.0 GPM
Air/Gases: See Gas Flow Adjustment Ranges below
Port Size: 1/2˝ NPT
Primary Construction Material: Brass or Stainless Steel
Setting Type: Adjustable
These externally adjustable switches are ideal for protecting machine tools from
coolant flow failure, for protecting bearings from loss of lubricant or to assure proper
air flow. They offer an infinite number of flow settings at pressures up to 1000 PSIG,
with low pressure drop and precise repeatability.
The adjusting vane is easily field adjustable using an ordinary flat-bladed screwdriver.
The adjustment is set-screw-locked for tamper-free operation after field calibration.
Specifications
Wetted Materials
Housing Brass or 316 Stainless Steel
Piston
In Brass Housing Polysulfone for water; Brass for oil or air
In Stainless Steel Housing 316 Stainless Steel Only
Spring 316 Stainless Steel
O-Ring Viton®
Other Wetted Parts Epoxy
Pressure Rating
Operating 1000 PSIG (69 bar)
Proof 2500 PSIG (172 bar)
Burst 5000 PSIG (345 bar)
Operating Temperature
With Brass or S.S. Piston -20°F to +300°F (-29°C to +148.9°C)
With Polysulfone Piston -20°F to +225°F (-29°C to +107.2°C)
Repeatability 1% Maximum Deviation
Set Point Accuracy ±10% Maximum
Set Point Differential 15% Maximum
Switch* SPDT, 20 VA
Inlet/Outlet Ports 1/2˝ NPT
Electrical Termination No. 18 AWG, 24˝ L., Polymeric Lead Wires
*See “Electrical Data” on Page X-5 for more information.
Air/Gas Flow Adjustment Ranges
Water or oil flow units should not be utilized for air/gas applications. The FS-10798
Gas Flow configuration utilizes a special dash-pot piston for reliability. The flow
adjustment ranges are typical for air service. For other gases, the flow range will vary
with the density of the gas. Please consult factory for more information.
For 5 PSIG Line* 1 to 75 SCFM Approx.
For 100 PSIG Line 3 to 160 SCFM Approx.
* Minimum 5 PSI line pressure required.
U.L. Recognized — File
No. E31926
CSA Listed —
File No. LR30200
Dimensions
With Wire Leads and Strain Relief
With 1/2˝ NPT Conduit Connector
Shown with optional 1/2”
conduit connector.
G-15
FLOW SWITCHES
Visit www.GemsSensors.com for most current information.
Media Materials Part Numbers
With Lead
Wires
With 1/2˝
Conduit
Connector
Housing Piston
Liquids Brass Brass (for Oils) 61205 49073
Polysulfone (for Water) 25357 25363
316 Stainless Steel 25358 25364
Gases Brass 25359 25365
316 Stainless Steel 25360 25366
FS-10798 Series / p2of2 / 30-JUL-14
SPRING
HERMETICALLY SEALED
SPDT SWITCH PERMANENT MAGNET
PISTON
HOUSING VALVE ADJUSTMENT
LOCKING SET SCREW
FLOW ADJUSTMENT
VANE
PISTON
MAGNETIC SWITCH
ADJUSTMENT
Flow diagram with switch
shown actuated.
2.0
1.5
1.0
0
0.5
0 0.5 1.0 2.0
2.5
FLOW RATE - GPM
PRESSURE DROP (PSID)
Part No. 25357
12
8
4
0
0 5 10 15 20 25 30
16
FLOW RATE - GPM
Tests conducted with units in horizontal position with water at +70°F (21°C).
Data will vary slightly for vertically mounted units.
PRESSURE DROP (PSID)
Part No. 25358
PISTON TYPE
How It Works
An externally rotatable vane is positioned in the main flow path within the unit. The
magnet carrier piston is located in a bypass flow chamber. Pressure differential,
caused by flow around the adjusting vane, displaces the spring-biased piston which
actuates a hermetically sealed SPDT reed switch within the unit.
How To Order – Standard Models
Specify Part Number based on desired media, piston material and electrical termination.
Notes:
1. Temperature changes will slightly affect the standard water or gas flow settings listed.
Oil flow settings will vary with temperature and viscosity.
2. Use of 50 micron filtration is recommended.
– Stock Items.
Pressure Drop - Typical
0.5 GPM
10 GPM and 20 GPM
FS-10798 switches are U.L. Approved for Class I,
Division 2, Groups A, B, C, D hazardous locations.
U.L. Approved — File No. E183854
Wire Color Terminal
Orange N.O.
Black Common
Red N.C.
Standard Wiring Color Code
