Standard Mounting Configuration
Vertical mount on a horizontal pipe — the default and recommended installation.
10× Pipe Diameter
Upstream Straight Run
Minimum before switch
5× Pipe Diameter
Downstream Straight Run
Minimum after switch
Within 5° of Vertical
Mounting Angle
Standard configuration
Installation Steps
Select the Correct Location
Install the flow switch in a straight run of pipe with a minimum of 10 pipe diameters of straight run upstream and 5 pipe diameters downstream. Avoid installing near elbows, valves, reducers, or other flow disturbances that create turbulence.
Verify Mounting Orientation
Standard installation is vertical mounting on a horizontal pipe run (switch body pointing up, paddle hanging down into the flow). Other orientations are available but must be specified at time of order. The switch must be installed within 5° of vertical unless otherwise engineered.
Install the Flow Switch
For threaded (NPT) models: apply thread sealant and hand-tighten, then wrench-tighten to the appropriate torque. For flanged models: align the flange, install gasket, and torque bolts evenly in a cross pattern. For wafer tee models: insert between flanges per the dimensional drawing.
Verify Flow Direction
Confirm that flow direction through the line matches the arrow or label on the switch body. Reverse flow will not actuate the switch correctly. For bi-directional (multiple action) models, flow direction is less critical — consult your order documentation.
Make Electrical Connections
Route conduit to the ½″ FNPT conduit connection (¾″ and metric available). Connect wiring per the terminal diagram on the nameplate. Standard SPDT: N.O. (Normally Open), N.C. (Normally Closed), and Common terminals. Verify voltage and current ratings match your application.
Adjust the Set Point
All PEECO flow switches are fully field-adjustable. With flow established, adjust the set screw to the desired actuation point. The switch should actuate cleanly with less than 10% dead band between make and break. Re-check adjustment after system reaches operating temperature and pressure.
Installation Requirements
- Minimum 10 pipe diameters straight run upstream
- Minimum 5 pipe diameters straight run downstream
- Install within 5° of vertical (standard configuration)
- Flow direction must match switch orientation
- All switches must be adjusted after installation
- Third-party calibration available upon request
Important Warnings
- Do not install in turbulent flow without appropriate options (Dash Pot, Stem Dampener)
- Do not exceed rated pressure or temperature without consulting PEECO engineering
- Explosion-proof models must be installed per NEC/CEC requirements for the hazardous location classification
- Do not modify the switch body, bellows, or stem assembly
- Verify electrical ratings before connecting to power
Field Adjustment
All PEECO flow switches must be adjusted after installation unless a third-party calibration has been requested and provided at time of order. The switch is fully field-adjustable across its entire operating range.
Water and nitrogen are used for factory flow testing to establish minimum activation and deactivation points. Field conditions (media, temperature, pressure, specific gravity) will affect the actual actuation point — use the velocity correction factors in the Flow Rate Table when working with fluids other than water.
Troubleshooting
Most field problems trace back to one of six root causes.
- Set point adjusted too high — reduce set screw tension
- Insufficient flow velocity — verify against flow rate table
- Paddle or vane not in flow stream — check orientation and insertion depth
- Wiring error — verify N.O./N.C./Common connections against nameplate
- Set point adjusted too low — increase set screw tension
- Debris or scale on paddle/vane — clean and inspect wetted parts
- Damaged return spring — contact PEECO engineering for replacement
- Turbulent flow at installation point — add Dash Pot or Stem Dampener option
- Insufficient straight pipe run — relocate switch or add flow conditioning
- Set point too close to actual flow velocity — adjust set screw
- Fluid specific gravity differs from water — apply velocity correction factors from Flow Rate Table
- Operating temperature affecting fluid viscosity — consult engineering
- Partial blockage of paddle/vane — inspect and clean
- Contact wear from excessive cycling — replace micro-switch
- Voltage or current exceeds switch rating — verify electrical specs
- Moisture ingress in enclosure — inspect conduit seal and gasket
- Insufficient thread sealant on NPT connection — re-seal and re-torque
- Flange gasket damaged or misaligned — replace gasket and re-torque in cross pattern
- Body cracked from over-torque or thermal shock — contact NCI for replacement
Still having trouble?
Our engineering team provides free technical support for all PEECO installations.