Dwyer SF2 User Manual

MAINTENANCE/REPAIR

SF2 Series

Sight Flow Meters

Regular maintenance of the total system is recommended to assure sustained optimum performance. These devices are
not field repairable and should be returned to the factory if recalibration or other service is required. After first obt aining a
Returned Goods Authorization (RGA) number , send the unit freight prepaid to the following. Please include a clear descrip­tion of the problem plus any application information available.

Dwyer Instruments, Inc.
Attn: Repair Department
102 Highway 212
Michigan City , IN 46360

Important Points!

Product must be maintained and installed in strict accordance
with the National Electrical Code and Dwyer product catalog
and instruction bulletin. Failure to observe this warning could
result in serious injuries or damages.

For hazardous area applications involving such things as (but
not limited to) ignitable mixtures, combustible dust and
flammable materials, use an appropriate explosion-proof
enclosure or intrinsically safe interface device.

The pressure and temperature limitations shown on the
individual catalog pages and drawings for the specified flow
switches must not be exceeded. These pressures and
temperatures take into consideration possible system surge
pressures/temperatures and their frequencies.

Selection of materials for compatibility with the media is critical
to the life and operation of Dwyer flow switches. Take care in
the proper selection of materials of construction, particularly
wetted materials.

Life expectancy of switch contacts varies with applications.
Contact Dwyer if life cycle testing is required.

Ambient temperature changes do affect switch set points,
since the specific gravity of a liquid can vary with temperature.

Flow switches have been designed to resist shock and vibration;
however, shock and vibration should be minimized.

Filter liquid media containing particulate and/or debris to
ensure the proper operation of our products.

Electrical entries and mounting points in an enclosed tank
may require liquid/vapor sealing.

Flow switches must not be field-repaired.
Physical damage sustained by the product may render it

unserviceable.

Instruction Bulletin No. 201917

(For Additional Information, See Dwyer Catalog)

SF2 Sight Flow Meter units monitor dynamic fluid flow . The rotor reacts
to turbulence, pulsation, entrained air, and other flow anomalies induced
in the flow stream by other process hardware. For optimum perfor­mance, install SF2 Sight Flow Meter units where nominal flow condi­tions exist, with ports located at the top. Incoming flow may be placed
to either port. A minimum of 8" of straight pipe on the inlet side is
recommended.

Low Flow Applications

A low flow adapter is supplied with all SF2 Sight Flow Meter units. It is used to produce accurate response at low flow
rates. Press fit the adapter as shown above, in the port selected for incoming flow. See Flow Range Chart below.

Flow Range - GPM

Port Size

NPT

.25"

.50"

.75"

1.0"

Input

Power

24 VDC

1 10 V AC

24 VDC

1 10 V AC

24 VDC

1 10 V AC

24 VDC

1 10 V AC

Model

Number

SF2-104
SF2-101
SF2-114

SF2-111
SF2-124
SF2-121
SF2-134
SF2-131

Standard

Range

0.5 - 5.0

4.0 - 20.0

3.0 - 30.0

5.0 - 60.0

Low Flow*

Range

0.1 to 1.0

1.5 to 12.0

N/A

N/A

* With use of low flow

adapter supplied

8" Min.

Low Flow

Adapter

←

Incoming

Flow

DWYER INSTRUMENTS,INC.

P.O.BOX 373 MICHIGAN CITY, INDIANA 46361, U.S.A.

Installation: SF2 Sight Flow Meters connect to piping via NPT mating thread forms. The following guidelines are provided to

assist with installation for a leak-free seal, without damage to the unit: 1) Apply pipe thread sealant to male pipe threads. 2)
Thread SF2 Sight Flow Meter unit onto male pipe thread until hand-tight. 3) Tighten pipe 1 to 1-1/2 additional turns. 4) If improper
seal results, continue turning pipe into unit in 1/4 turn increments. Do not exceed one additional turn. Recommended Pipe

Sealants: (a) Permatex® "No More Leaks" (b) Teflon® Thread Tape.

Filtration and Cleaning: 150 micron filtration is recommended. However, should foreign particles enter the SF2 Sight

Flow Meters, accumulation is easily cleared by removing the lens from the body. The lens is removed by turning its center rib 45°
counter-clockwise and then pulling it out. To reinstall the lens, simply reverse the process. Pressure must be relieved from the
system prior to sensor clean-out.

Phone: [phone] www.dwyer-inst.com
Fax: [phone] e-mail: [e-mail]
Lit-By Fax: [phone]

Specifications

Wetted Materials
Body
Rotor Pin
Rotor
Lens
O-Ring
Operating Pressure, Max.

Operating Temperature, Max.
Brass Body
Electronics
Viscosity , Max.
Input Power
Relay Contact Ratings (SPDT)
Repeatability
Set Point Accuracy (Factory Set)
Set Point Differential
Electrical Termination

Brass
Ceramic
PPS Composite/Teflon/PPS Composite
Polysulfone
Buna N/Viton
200 PSIG @ 70°F 80 PSIG @ 212°F

212°F (100°C)
150°F (65.5°C)
200 SSU
12 VDC, 24 VDC or 110 VAC
1 Amp, 24 VDC Resistive 0.5 Amp, 110 VAC
2% Maximum Deviation
±5%
15% Maximum
22 AWG PVC-Jacketed, 24" Cable. Color codes: Red = +VAC/VDC;
Black = Ground; White = N.O. Contact; Brown = N.C. Contact; Green = Common.

Panel Mounting

Any SF-2 sensor may be panel mounted using holes integrated into the bodies:
Two (2) mounting holes are provided on the body centerline, as shown below.
#8-32UNC-2B screws are required for mounting.

2.50"

3.06"

1/4" &1/2"

3.94"

2.5"

3/4" & 1"

Electrical Data

Input power and output are connected via a
multi-conductor, PVC-jacketed 24" cable.

Color codes are shown below:

+VAC/VDC
Ground
N.O. Contact
N.C. Contact
Common

Red
Black
White
Brown
Green

WARNING

When determining chemical compatibility of
materials of construction, the flow media and
application-associated environmental condi­tions should be carefully considered.

Switch Set Point Calibration with LED Signal

With the unit installed in the line and power supplied, complete the following steps to calibrate
switch actuation point with proper flow rate. A small flat-blade screwdriver is all that is required.

Adjust liquid flow in the line to the rate

1.
at which actuation is desired.

2.

Insert screwdriver into opening on
backside of housing and fit blade into
the potentiometer adjustment screw
inside.

3.

If LED is not illuminated, slowly turn
screwdriver counter-clockwise and
stop as soon as LED illuminates.

4.

If LED is illuminated, turn screwdriver
clockwise until LED light goes out.
Then, slowly turn screwdriver
counter-clockwise and stop as soon
as LED illuminates.

LED Indicator Is Illuminated
When Relay Switch Is
Closed. Aids Field
Calibration.

1/2" Strain Relief Hole

Cable
Output

Set Point
Adjustment