Dwyer P4 - Manual

Piston-Type Flow Switches
P4 Series
Notes
* Wrench flats provide for proper assembly
** Accepts 1/2" I.D. flexible hose
Installation . . .
Unless otherwise specified, the units are factory-calibrated with water mounting in vertical position, with lead wires
up. Observe proper direction of liquid flow, as marked "IN" and "OUT" on housing.
Be careful to keep foreign material out of units during installation. Use of 50 micron filtration is recommended. All
plastic NPT threads should be installed, using a suitable thread sealant, such as Teflon tape or Permatex "No
More Leaks". Sealant must be kept out of unit during installation.
Avoid over-tightening when connecting piping to unit, which is constructed of plastic material. Connection of
metallic piping to plastic units is not recommended.
Port Adapter Fittings . . .
Install plastic adapters with O-rings (supplied) directly into "IN" and "OUT" ports of the flow switch before installing
unit. CAUTION: Do not exceed 20 inch-pounds maximum torque when installing adapter fittings. Hold wrench
flats on adapters as indicated below when installing unit in piping to prevent additional torque accumulation
between adapter and body. (Note: Port adapter fittings must be purchased separately.)
- Warning -
These flow switches are plastic, straight-thread, O-ring
sealed instruments. Over-tightening will result in breakage!
P4 Models with SPDT Switches
P4 Models with SPST Switches
Typical Wiring Diagrams . . .
Port Adapters . . .
Adapter
Adapter
Size
Model
Numbers
1/8" NPT*
1/4" NPT*
1/2" Barb **
P4-98
P4-94
P4-92