Dwyer AFS User Manual

Piston-Type Flow Switches

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 products. 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.

Dwyer Products 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.

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

unserviceable.

DWYER INSTRUMENTS,INC.

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

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

AFS Series

Installation . . .

Install AFS models in piping system using standard pipe fitting procedures. Be
sure to keep thread sealing compound out of unit. Install so that flow is in proper
direction (marked "IN" and "OUT" on housing). Use of 50 micron filtration is
recommended.

Specifications . . .

Housing
Piston

Materials

Liquid Flow Adjustable Range - Water

Pressure

Ratings

Operating

Temperatures

Repeatability

Set Point Differential

Set Point Accuracy (Constant Temperature)

Factory-Set (Standard)

Air/Gas Flow Adj. Ranges:

(Dep. on Oper. Line Pressure)

Switch (See Electrical Data, Below)

Lead Wires

(In Brass Housing)
Piston (SS Housing)
Other Wetted Parts

Operating
Proof
Burst
With SS or Brass Piston
With Polysulfone Piston
For 5 PSIG Line*
For 100 PSIG Line

For 5 PSIG Line*: 1 to 75 SCFM (Approx.)

For 100 PSIG Line: 3 to 160 SCFM Approx.

-20o to +300oF(-29oC to +148.9oC)

-20o to +225oF(-29oC to +107.2oC)

Note: Temperature changes will slightly affect water or gas flow settings.

Oil settings will vary with viscosity.

*Minimum line pressure for positive actuation.

Electrical Data . . .

Switch Ratings - Max Resistive Load

VA

20

Volts

0-30

120
240

Amps AC

.4
.17
.08

Amps DC

.3
.13
.06

Typical Wiring Diagram . . .

Brass or 316 SS

Polysulfone for Water

Brass for Oil or Air

316 SS

316 SS, Viton, Epoxy

0.5 to 20 GPM
1000 PSIG
2500 PSIG
5000 PSIG

1% Max. Deviation

15% Max.

±10% Max.

SPDT, 20 VA

No. 18 AWG, 24" L., Polymeric

3-Pin Receptacle

Red

A

Black

C

Orange

B

Dimensional Data . . .

Electrical Connection . . .

Lead Wires

FLOW

Piping System

Unless otherwise specified, units are factory-calibrated in water for
in-line installation; in horizontal position, as shown above.

4-1/8"

1/2" NPT

(Both Ports)

Piping System

FLOW

2"

Flow Setting Adjustment...

Standard units are normally supplied with adjustment set at minimum flow ­adjusting screw slot (and vane within unit) in vertical position, as shown below.
Adjust unit on test stand or installed in system. With liquid (or gas) flow at desired
rate, adjust unit until switch first actuates (opens or closes, as desired).

Note: Vane is locked at Factory with set screw and must be unlocked prior
to any adjustment; then relocked after adjustment has been made.

Lead Wires,
Strain Relief

2"

1/2" NPT

Conduit Connector

1/2"

1-1/16"

1-1/4"

Maintenance . . .

Occasional cleaning when excessive contamination is present in the liquid is the
only maintenance normally required. To disassemble unit for cleaning: With
system shut down and no liquid in piping, remove piston plug from unit. Unit need
not be removed from system.

MAINTENANCE/REP AIR ...

Adjustment Screw with Slot in
Minimum Flow Position

Locking Set Screw

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. Af ter first
obtaining 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