What is the impact of fluorine-lined rotameters on the measurement range?
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1. By checking the specifications for rotor flowmeters, it can be seen that the measurement range of those with PTFE measurement tubes and PTFE floats is much smaller than that of those with ordinary stainless steel floats. Is this due to the density of the floats? 2. Is there a PTFE rotameter with DN50 that can measure 20 m3/h? The sample shows that a maximum flow rate of 16 M3/h can be achieved; most manufacturers can only reach 10 M3/h. 3. Is it possible to use a flow meter with a fluorinated lining for the measuring tube and an alloy float, thereby reducing costs while still allowing for a large measurement range?
That is the issue regarding the product series of the manufacturer that the original poster was inquiring about. There are rotameters with tubes lined with PTFE and metal floats coated with PTFE; I think it’s because you haven’t found the right manufacturer or asked the right person.
Most manufacturers are capable of producing products made of PTFE. My question is whether it’s possible to use PTFE for measuring high flow rates, for example, in the case of DN50
Rotary flow meters are not suitable for high flow rates. How high must the flow rate be? The maximum diameter of rotary flow meters is generally up to 150 mm, and the flow range can be adjusted to a certain extent depending on the choice of float. Your first question concerns the relationship between float density and flow rate; high flow rates were not mentioned in your primary question. Additionally, the selection of the measuring tube and float for rotary flow meters requires calculation by the manufacturer using software, rather than estimation. Flow rate is closely related to the selection of floats.
1. It’s definitely due to the difference in density; rotameters work by utilizing the principle of buoyancy, so no further explanation is needed. 2. The samples I have are in the range of 1–10 m3/h, and rotameters are generally used for measuring low flow rates; for higher flow rates, other types of flow meters should be used. 3. It depends on the specific medium being used; generally, they are designed to work together, as the material of the main body is usually the same as that of the float. Additionally, the float can be equipped with a weight, and if needed, you should contact the manufacturer directly to ask whether it’s possible to create such a design. It’s advisable to provide details about the medium to be measured as well as other relevant conditions, so that others can help determine the most suitable option
High-flow rates cannot be measured using rotameters
It is indeed due to the float; the fluorine-lined float being a non-metallic material results in a limited measurement range. Indeed, no metal float can be found in the lining.
For float flowmeters of the same caliber, the range of those with a fluorine-lined interior is generally smaller than that of those without such lining. The main reason is still related to the density of the float. Theoretically, reducing the density of the float allows for a larger mass to be achieved by changing its shape, or the range can be increased by altering the taper of the cone. However, when the range of a float flow meter is insufficient, this issue can be resolved by choosing a model with a larger diameter. Therefore, few manufacturers are willing to produce fluorinated lining products with a wide range of specifications in large quantities. Most manufacturers apply fluorine lining based on the existing standard models. Therefore, the range of fluorinated linings is smaller than that of those without fluorination.