The most diverse substances are transported and distributed in piping system every single day.
They can include solvents and chemical ,... oil and gas ...or steam for energy transmission
The fluids flowing through pipes often have completely different properties.
Therefore , different principles for their measurement are required.
One method is flow measurement based on the differential pressure principle.
Some 300 years ago, Swiss mathematician and physicist Daniel Bernoulli discovered the direct relationship between the pressure and speed of a fluid flowing in a pipe.
Italian physicist Giovanni Battista Venturi also performed experiments on flow and, in 1797, he built the first flowmeter for closed pipe -- known as the "Venturi tube".
Here is how this measurement method works.
Differential pressure flowmeters have an artificial restriction integrated into the measuring tube -- illustrated here by the example of an "Orifice Plate".
Two holes are located in the pipe wall , one before and one after the orfice plate.
Two separate tube connect these holes to a differential pressure sensor.
With it's two pressure chambers-- separated by a diaphragm -- the tiniest pressure differences in the flowing fluid can be precisely measured.
If the fluid is not flowing , the pressure before and after the orifice plats is essentially identical.
As soon as the fluid starts to flow, it's velocity around the orfice plate increases significantly because of the restriction in the cross --section.
At the same time , due to the laws of fluid mechanics, the static pressure at this point decreases.
Consequently , different values are detected in the pressure chambers of the sensor -- a higher pressure before and a lower pressure after the orifice plate.
This pressure difference is directly proportional to the flow velocity and thus to the mass and volume flow in the pipe.
The higher the flow velocity and the resulting drop in pressure around the orifice plate, the greater the differential pressure measured.
In numerous industrial application , the measurement technology.
However , other designs are available for certain measuring tasks to minimize undesired effects -- such as excessive pressure loss or abrasion of components due to solids carried in the fluid.
Nozzles with a rounded , funnel-- like inlet clearly reduce turbulence and thus create less pressure loss.
Nozzles are particularly suitable to higher flow velocities or to fluids with abrasive solid particles.
Turbulence reduction is even greater with Venturi Nozzles ... and finally with Venturi tube where the restriction is created by longer , conical constrictions in the pipe wall.
All these designs can be supplied with different restriction diameter sizes so that the pressure loss and the differential pressure generated can be optimized for the process condition.
Industrial flow measurement using different pressure has been tried and tested in numerous application worldwide for about 100 years.
With this measuring principle all liquids , gases or steam can be measured ever at extremely high process pressure and temperatures.
Every differential pressure flowmeter manufactured by Endress+Hauser is configured to customer specifications and premounted.
For all application , we have the right solution.
Endress+ Hauser -- your single -- source supplier for measurement technology!