ROTAMETER, liquid flow rate indicator.

Generically known as Variable Area Flow Meters

  • Simple & reliable.
  • Give instant visual indication of flow.
  • Mount in a vertical position only.
  • Ideal for applications with clear, clean liquids, such as:
  • Gland seal flows.
  • Bearing cooling water flows.
  • Analyser sample water flows.
  • Can be fitted with switches for digital alarm outputs for high & low flow rates.
  • Mercon meters come with solvent cement sockets sized to suit Australian pipe.
  • BSP female threads are an available option.
  • Manufactured from durable PVC materials.
  • EPDM standard, or optional FPM (Viton) “O” rings.
  • Short tube meters have a leader rod to stabilise the float.

Long Tube Flow Meter Size & Flow Rate

Long tube flow rate and price table

Short Tube Flow Meter Size & Flow Rate

Short tube flow rate and price table


  • ALo is a low flow alarm.
  • AHi is a high flow alarm.
  • 2AHL is a dual alarm for low flow & high flow.
  • Alarm contacts are reed switches, rated at 100mA at 24VAC. Use interposing relays for high currents or voltages.



Is a 1″ NB (DN25) long tube flow meter, range 100 – 1000L/H with solvent socket connections & a dual alarm output for high & low flow rates.

We can offer meters in sizes up to 6″ NB (DN150) for flow ranges up to 200M³/H with flange connections & a choice of “O” ring materials. Please call to discuss your special requirements.


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Phone 02 4351 4022