The GEMU 840 flowmeter operates according to the part flow principle and consists essentially of three parts: Main flow unit, part flow unit and manual diaphragm valves.

Main flow unit: The material used is PVC-U or PP. The orifice material can be selected as either PVC-U, PP or stainless steel. The body has plain or welded spigots enabling it to be connected by means of unions or flanges.

Part flow unit: Plastic flowmeter which operates according to the variable area principle with integral metering orifice, housing material: polysulfone. The float is made of PVC-U or PP which can also be fitted with a magnet for electrical detection of the flow rate. Dovetail sections moulded onto the metering tube allow for easy mounting of adjustable visual flow indicators (supplied with the flowmeter) and limit switches.

Manual diaphragm valves: The part flow unit can be removed from the main body of the flowmeter without interrupting the main flow by closing the manual by-pass valves.

  • Good level of accuracy, simple operation
  • Impact resistant, corrosion resistant
  • Large measuring range 3 - 50 m3
  • Part flow tube can also be easily replaced without downtime


Float Material/Working Medium PP (Liquids) PP with magnet (Liquids) PVC-U (Liquids) PVC-U with magnet (Liquids)
Nominal Size DN 65
Body Configuration Straight through pipe
Connection Spigots DIN
Tube Material PP PVC-U
O-Ring Material EPDM FPM
Orifice Material of Main Flow Unit PP PVC-U Stainless Steel (1.4571)
Orifice Diameter 36 mm40 mm44 mm48 mm52 mm
Measuring Range 3 - 20 m³/h4 - 25 m³/h5 - 32 m³/h6 - 40 m³/h8 - 50 m³/h

Working Medium

Working Medium Inert and corrosive liquid media which have no negative impact on the physical and chemical properties of the tube, float, seal and body materials or any other medium wetted parts.
Standard Range Measuring ranges are based on medium water at 20°C
Accuracy Class 4 ace. to VDE/VDI 3513, i.e. ±1% of end value and ±3% of measured value
Working Pressure 10 bar