venturi fabrication

[MartinAir]

Hi,

I'm interrested in the fabricationprocess of venturi tubes for flow measuring.

This is a venturi tube:

http://www.mattech.cz/en/vent_trubice.htm

The medium is dry air and the pressure is <1500 Pa

I was thinking of plumbing pipes made of steal. But there would be better if I could get aluminium parts. Is there any standard pipes from some other industry that could be used where aluminium pipes, concentric reducers with different angles (the most important).

Regards