Dwyer P3 User Manual

In-Line Flow Switches

P3 Series

Installation

All NPT threads should be installed using a suitable
thread sealant (Teflon tape or Permatex “No more
Leaks”). Sealant must be kept out of unit during
installation. Ten diameters of straight run piping are
recommended upstream and downstream of the flow
sensor.

Specifications

Wetted Materials

Housing, End Fitting
Piston
Spring

O-Ring
Oper. Pressure, Max.
Operating Temperature
Required Filtration
Set Point Accuracy
Set Point Differential
Switch, See “Switch Ratings”
Inlet / Outlet
Electrical Termination

Hydrolytically Stable Glass Reinforced Polypropylene
PPS Composite
316 Stainless Steel
Fluorocarbon
200 PSI at 70°F, 100 PSI at 212°F

-20°F to +212°F (100°C)
100 Micron or Better
±20%, Maximum
20% Maximum
SPST, 10 VA
3/8” NPT Male or Quick Connect
No. 24 AWG, 24” to 26” Polymeric Leads

End Fitting

Outlet

Body

Inlet

Spring

P3 Flow Switches Can be Mounted In
Various Positions

Flow settings are based on a vertical
position (inlet port down), using water at
+70°F on increasing flow. Some variation
in set point actuation will occur in other
mounting orientations.

16
14
12
10

8

PSI Drop

6
4
2
0

0 1 2 3 4 5 6 7 8

Pressure Drop - Typical

Switch Ratings

Contact rating: 10W
Switching Voltage (DC or AC Peak): 200 Max.
Switching Current (DC or AC): 0.4 A Max.
Carry Current (DC or AC): 0.4 A Max.
Break down Voltage: 230 VDC Min.

Wiring Diagram

Normally Open

Flow Rate - GPM

3/8” NPT Ports

Quick Disconnect Ports

Dimensions

11/16” Hex.

1” (25 mm)

4”

(102 mm)

1” (25 mm)

11/16” Hex.

O-Ring Typ.

.75” (19 mm)

Across Flats

.43” (11 mm)

Dia. Typ .

4.22”

(107 mm)

MAINTENANCE/REPAIR

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 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

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.

Important Points!

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