HEX800 Series Flow Meter
The HEX800 flow meter is an insertion style electromagnetic flow sensor for pipelines from 1" to 12" in size. This equates to a fluid velocity range of 0.28 to 20 FPS which means that the maximum flow rate would be approximately 7,000 GPM with a 12" pipeline. Remember, if used in a non-alloy pipeline with our non-alloy valves and strainers, the recommended velocity falls within the <8 FPS range.
What is an electromagnetic flow meter?
Electromagnetic flow meters work with moving conductive fluids. As fluid passes through the magnetic field created by the flow meter, an electromagnetic force results. This electromagnetic force is voltage and based upon the pipe diameter the velocity can be calculated. This operating principle is based upon Faraday's Law of Induction where energy (voltage) is proportional to velocity, magnetic field strength and the pipe diameter.
Advantages of an electromagnetic flow meter are that the fluid pressure, density, viscosity and temperature do not affect the accuracy. Aerated fluids or fluids containing solids are also compatible with this style of flow meter. In-fact since the The HEX800 flow meter has no moving parts to repair/replace, it is considered better for reclaimed or abrasive fluids, complimenting our sealless pumps quite well.
Drawbacks include that the fluid needs to be conductive (at least 20 microsiemens/cm), therefore this type of flow meter will not work on gasses or liquids such as DI water, methanol and ethanol which are not conductive. The HEX800 also requires a short section of straight pipe to insert the flow sensor.
Since most of our PVC/CPVC and polypropylene strainers, valves and filters are used for water and water-like liquids the HEX800 will be suitable for most of our customers applications.
The body is made from PVC and has a PVDF end cap. The electrodes are made from Hastelloy-C and the o-ring seal is EPDM. The housing itself is aluminum.
Powered by 24 VDC, the HEX800 is rated for non-shock pressures up to 150 PSI at 75ºF and can be operated within a temperature range of 32ºF - 130ºF and maintain its ±1% full scale accuracy.
The base unit has a blind 4-20mA output (square wave pulse, opto isolated, 550 Hz @ 20 ft/secand) and there's an option for a built-in indicating transmitter as well as batching controller.
We can provide a complete range of insertion fittings to make sure the flow sensor is inserted to the correct depth.
Best Installation Practices for Electromagnetic Flow Meters
Install the flow sensor such that there is a length equivalent to at least ten pipe diameters upstream and five pipe diameters downstream.
Having sufficient lengths of straight piping helps to ensure a relatively turbulence-free flow, otherwise accuracy may suffer. Sometimes the ideal installation isn't possible and reliance on repeatable readings is emphasized over the actual readings themselves.
The position or orientation of the flow sensor can also be an important consideration, especially if your fluid is aerated or has sediment. Mounting the flow sensor one the "side" of the pipe is usually the best position.
Please view/download the HEX800 IOM manual for complete set-up instructions and specifications.