For flow-rate measurement of aggressive and non-aggressive gases, steams and fluids especially if low pressure loss is indicated.
It consists of an inlet cylinder, an outlet cone which is being followed by a cylindrical neck and the outlet cone. Classical venturi tubes are being carried out in several types of construction corresponding to the make of their inner surface. You differentiate betwe en either venturi tubes with treated in let cone, inlet cylinder and neck or venturi tubes with rough, with welded (steel panel) in let cone. Depending on the nominal diameter the neck is either treated or not. Venturi tubes are welded constructions out of steel or high-grade steel with predominantly rounded cross section. In particular cases angular cr oss sections are possible; those are exclusively manufactured out of rolled plate. Positive and negative pressure tapping takes place in the tube wall each through one or several single bores. When having bigger nominal diameters it is recommendable to connect them with a circuit. The calculation is accorded to ISO 5167-3.
Classical venturi tubes have little pressure losses depending on the make of the inlet cone and the opening angle. In contrary to all other DP-flow elements only short upstream paths are needed. When having venturi tubes which are big and completely out of steel panel the weight is much lower than comparable venturi tubes.