Cross ventilation of the inside of a hydraulic housing of a metering pump, dispenser or remote pumping unit shall
be provided and the total effective area of the ventilation openings shall be not less than the greater of 8 000 mm2
or 3,5 % of the maximum horizontal internal cross-sectional area of the hydraulic housing at the base of the
metering pump, dispenser or remote pumping unit. At least 50% of this minimum ventilation area shall be at the
lower