Variable area flow meters (rotameters) and other mechanical flow meters are not typically permanently installed in closed-loop geothermal systems since they add pressure drop, add cost, and can become cloudy or fail over time. Further, most geothermal systems require installation on all piping and components, so the insulation would have to be removed from the meter to read it. However, flow meters can be useful during system flushing and startup on non-pressurized flow centers (see graphic below). Our 3762 flow meter tool allows the technician an easy way to measure the flow rate to ensure the proper flow velocity for flushing and/or operation. Note that variable area flow meters are calibrated for water. If there is antifreeze in your system, the flow rate displayed on the meter must be corrected.
PDF: