【2026 Flow Measurement】Selection of gas flow meters — Vortex flow meters and turbine flow meters
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Vortex street and turbine – these two names differ by just one character, and many people get them mixed up when making selections; they even end up entering the wrong model on the purchase order. But they are fundamentally based on two completely different sets of principles. The standard answer to this question is: none is absolutely better; it depends on what gas you are measuring and what you intend to use it for.
I. First, understand how each of them works – one is for \"counting vortices\", and the other is for \"counting rotations\". Vortex Flowmeter: Its principle is based on the \"Kármán vortex street\" phenomenon in fluid dynamics. A fixed flow disruptor (vortex generator) is installed in the pipe; as gas flows through it, regular vortices are generated alternately on both sides downstream of it. The frequency of the vortex is proportional to the flow velocity; by counting this frequency using piezoelectric sensors, the flow rate can be calculated.
In simple terms: it’s like there’s a stone in a river; as the water flows past it, two alternating vortices are formed downstream. By counting the speed generated by the vortex, one can determine how fast the water flow is.
Key feature: There are no moving parts; the entire measurement process involves being a stationary \"observer\" who simply counts the vortices with their eyes.
Turbine Flowmeter: The principle is much more intuitive. A turbine with blades is installed in the pipeline; as gas flows past, it pushes the blades to rotate, and the speed of the turbine is proportional to the flow rate. A magnetoelectric sensor is used to detect the rotational speed of the turbine, which is then converted into pulse signals to calculate the flow rate.
In simple terms: it’s like a windmill that is pushed by the wind; the stronger the wind, the faster it spins. By counting how many times it rotates, one can determine the strength of the wind.
Key feature: It has moving parts – the impeller rotates and the bearings wear out; it is a moving mechanism subject to wear.
II. Horizontal comparison across nine dimensions — One key difference
III. To choose the right instrument, two factors are key. Question 1: What gas are you measuring? For measuring steam, dirty gases (compressed air containing dust and oil mist), and gases with fluctuating composition – choose vortex flow meters. Vortex flow meters have no moving parts, so they are not susceptible to wear caused by impurities. Vortex flow meters are the only universal type of flow meter capable of measuring gases, liquids, and steam.
For measuring high-value clean gases, natural gas trade transfers, and applications requiring the highest precision – choose turbines. The accuracy of turbines in clean gas measurement can reach ±0.5%, which is much higher than the ±1% of vortex flow meters. The turbine is one of the statutory instruments for measuring natural gas trade, with established standards and widespread application.
Question 2: Do you want “convenience” or “high precision”? Low maintenance, requires little upkeep, and not picky → Choose vortex flow meters. No wear-prone parts – once installed, you don’t have to worry about them for years. The requirements for medium cleanliness are relaxed; there is no need to worry about installing filters or replacing bearings regularly.