Venturi Tube Flow Meter also measures flow rates by constricting fluids and measuring a differential pressure drop.In the upstream cone of the Venturimeter, velocity is increased, pressure is decreased.Pressure drop in the upstream cone is utilized to measure the rate of flow through the instrument

Features of Venturi Meters

a.    Design Pressure: No limitation. Limited by DP transmitter/ pipe press ratings.
b.    Design Temperature: No limitation. Limited by DP transmitter/ pipe pressure ratings
c.    Sizes: 25 mm to 3000 mm
d.    Fluids/ Applications: Clean Liquids/ clean gases
e.    Limited applications: Dirty /corrosive/viscous Liquids & Dirty gases
f.     Flow range: limited only by pipe size and beta ratio.
g.    MOC: No limitation (cast iron/ carbon steel/ SS/Monel, Titanium, Teflon, Hastelloy, Naval Bronze / haste alloy)
h.    Accuracy: It varies from ±0.25% to ±0. 75% of actual flow. The accuracy of DP transmitter varies from ±0.1% to ±0. 3% of full scale error.
i.      Rangeability is 3:1 to 5:1.
j.      Upstream length/ Downstream straight length is 20 / 5