VZO is a volumetric meter with an oscillating piston. Its design makes it extremely rugged and highly accurate, even at low flowrates. VZO may be installed horizontally, vertically or at an angle. When used with burners, it may be fitted directly on the nozzle line. Its metering chamber can be easily cleaned without removing the meter from the pipe.
VZO is made of cast iron, bronze and aluminium piston and is particularly suitable for metering non-aggressive liquid lubricants such as fuel oil or mineral oil.
Modular, VZO may be fitted at any time with a pulse emitter. The variety of values and pulse types make VZO compatible with all centralised technical management systems. The version with an electronic register (VZF) offers a multifunctional display facility, as well as pulse and analogue outputs.


  • High measuring accuracy
  • Smart meter
  • From 1 to 5,000 mPa.S
  • DN 15 to DN 50
  • Fuel and oil measurement
  • Metering in both flow directions
  • Technical characteristics
    Nominal diameterDNmm1520254050
    Nominal diameterDNinch1/2 "3/4 "1 "1-1/2 "2 "
    Nominal pressure with threaded endsbar1616161616
    Nominal pressure with flanges*bar2525252525
    Maximum temperature*°C130130130130130
    Metering in both flow directionsyesyesyesyesyes
    Maximum flow rateQmaxl/h6001,5003,0009,00030,000
    Permanent flow rateQcontl/h4001,0002,0006,00020,000
    Minimum flow rateQminl/h204075225750
    Starting flow ratel/h4123090300
    Error tolerance of volume between Qmin and Qmax< ±1 %< ±1 %< ±1 %< ±1 %< ±1 %
    Repeatability< ±0.1 %< ±0.1 %< ±0.1 %< ±0.1 %< ±0.1 %
    Volume of the metering chamber (cyclical volume)cm³12361003301,200
    Verification stepl0.
    Recording capacity1,00010,00010,00010,000100,000
    Max. recording time with continuous flow and no reseth2,50010,0005,0001,6675,000
    Width of the safety filter meshmm0.
    (*) Version up to 180°C also available.
  • Pulse values for emitters (l/pulse)
    Nominal diameterDNmm1520254050
    IN (Inductive) K=
    IN (Inductive) K=10.10.11110
    RV (reed) K=10.111110
    RV (reed) K=101--10100
    VZF programmable pulsemax. freq. 100Hzmax. freq. 100Hzmax. freq. 100Hzmax. freq. 100Hzmax. freq. 100Hz
    VZF passive analogue outputmA4-204-204-204-204-20
  • Electronic register (VZF)
    Displayed valuesTotal volume, volume with reset, instant flowr ate value. Run time and other information in Service submenu.
    Display8-segment LCD with parameter identification, 8-mm digit height, instant flow rate value (meter load) by a bar diagram.
    TemperatureAmbient temperature -10°C to +70°C / Storage temperature -20°C to +80°C
    SafetyEC, fatigue and impact resistance tests to DIN IEC 68
    Power supplyStandard lithium battery, CR 1 / 2AA or CR2 type
    Data backupNon volatile EEPROM memory
    Battery replacementAfter five years, on the basis of a six-year lifetime, with digital display of the instant value for 10 hours max.
  • Dimensions : Body with threaded ends
    Nominal diameterDNmm1520254050
    Height under pipebmm455477116
    Meter diameterØfmm105105130210
  • Dimensions : Body with flanges
    Nominal diameterDNmm1520254050
    Height under pipebmm455477116166
    Flanges diameterØemm95105115150165
    Meter diameterØfmm105105130210280
  • Assembly

    Rotary piston meters may be fitted on horizontal or vertical pipes at an angle. They do not require the presence of straight lengths before or after the meter. The dial of the register must never be installed head down. Rotary piston meters are precision instruments and must always be protected by a filter. The mesh width must be less than 100 microns (0.1 mm).