The venturi tube is a method of measuring fluid flow using a cylindrical depressurizer with a restriction.
As a fluid flows through the tube, its flow rate increases due to the restriction. The pressure difference between upstream and downstream is proportional to the flow rate.
Venturi tube flowmeters offer high accuracy and long stability. These flowmeters are easy to use and have a low cost of ownership. What's more, they are capable of operating in harsh conditions, making them ideal for measuring the flow of liquids, gases and steam. Thanks to their rugged construction, venturi tube flowmeters are also suitable for applications requiring high resistance to corrosion and shock. These instruments are therefore ideal for flow measurement in the most demanding production processes and industrial applications.
HIGH PRECISION
LONG STABILITY
COMPLIANT
LOW PRESSURE LOSSES
The phenomenon of Bernoulli's theorem applies to venturi tube flow measurement.
This physical law of fluid mechanics describes the relationship between the velocity, pressure and flow rate of a fluid.
In particular, this equation can be used to calculate the pressure difference created as the fluid passes through this pipe.
As the fluid passes through the neck, the principle of the venturi effect, created by the constriction, increases its velocity and creates a pressure difference between the two ends.
This pressure difference is proportional to the fluid flow rate and can be accurately measured by a differential pressure transmitter.
A venturi tube flowmeter consists of a differentialpressure transmitter and a tube with a constriction.
This is constructed with a smaller converging cross-section at the inlet and a diverging outlet. Fluid flow is always in the direction from the larger to the smaller cross-section through the neck.
The upstream inlet of the tube is connected to the high-pressure port of the differential pressure transmitter , and the downstream outlet is connected to the low-pressure port.
As the fluid enters the instrument, its velocity increases and its pressure decreases. The differential pressure transmitter measures the pressure difference between the inlet and outlet of the venturi tubes.
This variation in head loss is converted into a measurable flow rate.
Venturi tubes are available in different versions and diameters for a variety of uses.
They are made in France, machined from solid or from forged parts, and come in either flanged or welded versions.
There are also many non-industrial applications for venturi flow measurement.
Since venturi-type depressurizers are capable of measuring flows ranging from a few tens of liters per minute to several hundred cubic meters per second, they can be used in a wide range of applications.
This method is widely used in hydraulic processes and aerodynamics to measure fluid velocity in piping.
Industrial sectors that use venturi tube flow measurement are the metallurgy, chemical and oil industries. These sectors need to measure and control the flow of liquids and gases (air, nitrogen, etc.).
Venturi flow measurements enable them to regulate industrial processes,optimize yields and reduce energy consumption.
