IOM Guide
Installation, Operation
& Maintenance
Complete field guide for threaded and wafer-style Flo-Gage™ flowmeters — from mounting and orientation through zero adjustment, calibration, and correction factors.
1. Principle of Operation
Flow rate is measured by the pressure differential across a machined flow nozzle in the meter body. Opposed bellows sense this pressure difference and move a mechanical linkage to drive the flow indicator needle.
For digital versions, the bellows and mechanical linkage are replaced with a solid-state differential pressure sensor. See the full IOM manual for digital-specific wiring and configuration.
Safety — Section 3.1
- Never exceed pressure or temperature limits marked on the nameplate.
- Overpressure can cause injury or permanent meter damage.
- Contact the factory for high-temperature applications.
2. Installation Planning
- Choose a location with easy visibility and service access.
- Ensure 10 pipe diameters of straight piping upstream of the flowmeter for accurate readings.
- Flowmeters are calibrated for Schedule 40 pipe — avoid tubing or hoses without proper transition fittings.
- Avoid water hammer, vibration, or freezing conditions.
- Outdoor or splash-exposed meters should use a gasketed case (Option D / D2, NEMA-4X / IP-66).
3.2 Dial Orientation
The dial face can be rotated in 90° increments for better readability by removing four screws. Do not remove the housing screws.
After reorientation, re-zero the meter using the fine adjustment procedure (Section 4.5).
3.3 Horizontal ↔ Vertical Conversion
- Rotate the dial and reinsert using the locating indents.
- After reorientation, re-zero using the fine adjustment procedure.
3.4 Threaded Bodies (Series 7000)
Use proper thread sealant; ensure threads are clean and free of burrs before installation.
3.5 Wafer Bodies (Series 8000)
Mount between flanges, ensuring gaskets are centered to prevent flow errors. Suitable for 150 or 300 lb class flanges.
7. Summary & Best Practices
- Ensure proper installation alignment, sealing, and orientation.
- Re-zero after any adjustment, cleaning, or reorientation.
- Prevent mechanical stress, vibration, and overpressure.
- Always open valves slowly to avoid water hammer.
- Periodic inspection of zero, reed switches, and cleanliness ensures long-term accuracy.
- Correction formulas allow use with various fluids and gases without factory recalibration.
Flo-Gage™