Flow Direction for Venturi Tube

They are unidirectional devices, so reversing them is counterproductive.

If all you're doing is a simple calculation, as in a freshman fluids class, direction doesn't usually matter. If you're doing a real venturi design, say for the eductor of a paint sprayer, it matters a great deal. What you call the "tapping point" is what I might call the injection point and that works in a quite asymmetrical way. In addition, the inlet and outlet tapers are often not the same; outlet pressure affects the efficiency quite a bit.

Is this homework or a real design? If a real design, please share some details and we may be of some help.

no.it will not work in counter directions aswhen the direction will be reversed the inclined angle and the declination angle will be different,and you cant make them both same in regardance of space and cost..also in technical aspect the inclination degree should be less than declination[input side] because of pressure head recovery without forming vortex and countering flashing phenomenon.

It must be unidirection. every venturi flowelement is comming with flow direction.

Inclined and declined angles are not same. so amount of specific pressure drop wont take place as you know in flow calculation A1 and A2 also considered.

If you are ordering , then close your eyes....vendor will mark the direction 100%

Direction has to be mentioned as the length of diverging section (from throat dia to outlet dia) is more than the that of converging section(from inlet dia to throat dia).

Anant.