Project Description


The Hoverflo will accurately measure the flow of highly corrosive, aggressive and non lubricating liquids and chemicals.

  • All plastic bearingless design 
    – No maintenance
    – No corrosion
    – No wear
  • Accurate metering of difficult liquids 
    – Well proven
    – Reduce waste and costs
    – Improve product quality
  • High quality manufacture 
    – ISO 9001 certified company
    – Approvals for use in hazardous areas
    – Individual calibration certificates


This range of flowmeters is used for measuring highly corrosive solutions such as nitric, sulphuric, hydrochloric and hydrofluoric acids. It is ideal for measuring aggressive and non-conductive liquids which have proven to be incompatible with most magnetic and mechanical flowmeters.
The long term reliability and stability of the Hoverflo make it ideal for both batch and continuous process operation.
In hazardous areas you can use the flowmeters with the Apollo IS pick-off coil, approved to ATEX II 1G EEx ia IIC T5/T4. The signal can be used in the IS area or transmitted to the safe area using the intrinsically safe P5 preamplifier and suitable barriers.

Principle of Operation

The flowmeter has two turbines connected by a central shaft. The liquid flows through both turbines, spinning the shaft whilst it hovers. The lower turbine has magnets sealed in the rim which are detected by the sensor to generate pulses. The frequency of the pulses is proportional to your flow rate.


The signal can be used for a local display, remote display or converted for transmission to a separate control system. Apollo have a range of instruments to suit all your requirements.


All wetted parts are either PVC or PVDF for maximum chemical resistance. The seals are PTFE or piton. The meter combines the advantages of a turbine flowmeter without the problems of bearing wear.


All Apollo flowmeters are individually calibrated with water and are traceable to national standards. We provide you with a test certificate for each meter showing the number of pulses per litre, which is used to set the instrumentation.


The flowmeter is installed horizontally in the pipeline. To reduce turbulence and achieve the best results from your flowmeter we recommend that you install it in a straight section of pipe with at least 10 pipe diameters upstream and 5 pipe diameters downstream.
Control valves should be installed downstream of the flowmeter.The flowmeter must be kept full of liquid and reverse flow must be avoided.
An amplifier is required if you need to transmit the signal more than 4 metres, or if there is an electrically noisy environment close to pumps, solenoids, switchgear or high current cables.
Intrinsically safe systems always require an IS pick-off coil. The IS P5 preamplifier is required for transmission to the safe area through barriers.