Pressure Switch Installation and Operating Guide
Pressure switches provide on/off detection for pressure-based control and safety applications. They are used for pump control, compressor protection, and safety shutdown systems.
I. Installation
- Mount the switch in a location accessible for adjustment and testing. Avoid areas with excessive vibration or temperature extremes.
- Use a gauge snubber or pulsation damper in applications with pressure pulsations to prevent premature switch wear
- Install a siphon loop for steam service to protect the switch from direct steam temperature
- Connect the process using appropriate fittings. Apply sealant carefully to avoid contaminating the switch internals.
II. Setpoint Adjustment
- Determine the desired actuation and deactuation pressure values based on the application
- Connect a calibrated pressure gauge or calibrator to monitor the applied pressure
- Gradually increase pressure to the desired setpoint and adjust the switch until it actuates
- Verify the reset (deadband) value by decreasing pressure and confirming the switch deactuates at the correct value
- Cycle through setpoint and reset multiple times to verify repeatability
III. Wiring and Testing
- Wire switch contacts to the control system. Verify contact rating is adequate for the connected load.
- For electronic switches, verify power supply voltage and polarity
- Test switch operation by varying pressure and confirming the output changes state correctly
- Test the entire safety loop from switch to final element for safety instrumented applications
IV. Maintenance
- Test switch setpoint quarterly for critical applications
- Inspect electrical connections for tightness and corrosion
- Replace switches showing setpoint drift or mechanical wear
