Industrial machinery is a complex combination of devices functioning to achieve a specific goal. Some of these devices, no matter how minute are vital to the proper function of a machine. Flow meters, for example, are responsible for measuring mass, linear, volume, non-linear, and linear flow of gas or fluid. Some intangible factors affect the choice of flow meters in different industrial applications. Engineers need to consider the following: the experience and familiarity of plant workers, their knowledge of calibration and maintenance, and availability of parts.
In most industrial applications, a common mistake made is justifying the use of a cheaper device that does not accurately fit the intended use. While the initial purchase may be cheap, it can result in costly repairs and installation issues. Avoiding errors and installation problems are some of the reasons flow meter selection is a crucial step that requires careful consideration.
Choosing the right flow meter
The basic rule of flow meter selection involves an explicit evaluation of the requirements of the intended application. Categorising each factor helps with a complete assessment leaving no area unchecked. Here are the factors to consider in flow meter selection:
- Fluid characteristics and nature of the flow. The fluid has various attributes that impact the accuracy of flow meter measurement. These characteristics include viscosity, density, pressure drop allowable, and temperature. In addition to these, there should be detailed information on toxicity levels, light transmission qualities, the presence of solids, and presence of bubbles.
- Temperature range and pressure. In addition to the average temperature and pressure operating values required for flow meters, the maximum and minimum values are also considerations. Other factors related to these are a reversal of flow, the likelihood of pulsation and aeration, occurrence of sudden temperature change, and specialised maintenance and cleaning requirements.
- Installation area. Installation area covers the piping where the flow meter is attached. The piping direction of pipes, its size, fabrication, the presence of valves, regulators, and whether there are upstream or downstream turns. Engineers should be aware of magnetic fields present in the area, as well as possible sources of vibration. Other considerations for the installation area include safety, clean-up, and hazard regulations.
- Flow rates and accuracy required. After identifying all the external factors, the next step is to know the required measurement range. The measurement range includes identifying the minimum and maximum flow range either in mass or volume. These parameters help determine the flow measurement accuracy range. For specific applications where meter reading is vital, accuracy is a critical requirement. On the other hand, there are other applications where it is more critical to establish repeatability rather than accuracy.
- Measurement unit in mass or volume. Determining whether the unit of measurement is mass or volume is another consideration in choosing flow meters.
Choosing the right flow meter for industrial applications is not a simple matter. Engineers understand the gravity of finding the exact device fit for its intended use. Flow meters are invaluable tools that have become part and parcel of machine operation. They are essential to many of the processes involved in modern living.