Metering plunger pumps and units can be assigned for voluminous pressure metering of neutral and aggressive liquids, emulsions and slurry oils which have kinematic viscosity from 8,5x10-7 to 8x10-4 m²/s (from 0,0085 to 8 St); temperature from 258K to 473K (from minus 15°C to plus 200°C and more); nonabrasive solid phase concentration not more 10% in the mass with maximum particle density up to 2000 kg/m³; particle size of nonabrasive solid phase not more than 1% from internal diameter of inlet nozzle.