This article will outline important factors to consider when selecting a flow meter. Read about how to select the perfect flow meter for your application below.
Price vs Popularity
Price plays an obvious role in selecting a flow meter. We all have budgets to follow. It is common for people to search for the best price when selecting a flow meter. We do want to caution using this as your main factor when in the selection process. If you place the price at the top of your criteria, it will be easy to get the wrong flow meter for the application or one that does not perform well. The bargain price you thought you had will dissipate having to buy ancillary equipment and performing expensive maintenance.
Another common factor is popularity. It’s important to research the Flowmeters most used in your industry. Be that as it may, using this as the only factor in your decision making will also cause problems. When a flow meter is not suitable for an application measurement can be inaccurate. This leads to the loss of valuable materials and loss of revenue. Advancements in technology can also put instruments on the market that are not well-known but provide a better solution. An example of this is how inline ultrasound flow meters had to be recalibrated when introducing a new fluid. New technology has solved these problems and allows for the use of these flow meters.
Volume or Mass Flow Measurement
Flow meters have use either Volumetric flow measurement or Mass flow measurement. Choosing between a volumetric flow meter or a mass flow meter is dependent upon your application. Before choosing a flow meter make sure to understand the purpose of your application and its components.
Flow meter categories based on fluid
Flowmeters do not work within every application. For instance, electromagnetic flow meters need a conductive liquid. They also will not work with hydrocarbons. This is one example, listed below are the main flow categories, paired with the fluid type the meters can handle.
- Gas– Coriolis Mass, Thermal Mass, Ultrasonic, Variable Area, Variable Differential Pressure, Positive Displacement, Turbine
- Liquid– Coriolis Mass, Thermal Mass, Ultrasonic, Variable Differential Pressure, Positive Displacement, Turbine, Electromagnetic
- Slurry – Coriolis Mass, some subsets of Variable Differential Pressure, Electromagnetic, Ultrasonic
- Vapor – Vortex, Ultrasonic, Diaphragm, Floating Element
Properties of the Application & Fluid
It is imperative to understand the physical properties of the application site, such as:
- Configuration of the pipe before and after the flow meter and the length of straight pipe at the inlet and outlet of the flow meter.
- The size of the pipe. Some flow meters have a poor performance with very small pipes and some cannot measure fluids in larger pipes
- The material of the pipe
- The surrounding environment and whether it is stable or variable
- Will the flow meter work at a certain angle? This can affect a flow meter’s performance
Its also important to understand the properties of the fluid measured. Below are some of the primary components:
- Type of fluid – liquid, gas, slurry, vapor
- Condition of the fluid – foreign objects in it, suspended particles, air bubbles,
- Other contaminants
- Flow consistency – consistent or breaks, fill the pipe or fill
- Flow range – the min. and max. of the flow
- Corrosive nature of the material – corrosive liquid or gas can deteriorate inline sensors
Flow Meter Specifications
Lastly, the specifications of the application must be considered when choosing the right flow meter.
To even suggest that accuracy is a variable seems ridiculous. Who would want an inaccurate meter? But the importance placed on accuracy varies dependent on the application. Some applications do not even require precision.
Repeatability means the number of times (%) you get the same results running the same test or measurement under the same conditions. Repeatability is not about accuracy, rather consistency. Many will say that the repeatability of a flow meter is considered more important than accuracy
Turndown Ratio or Rangeability
This implies the range that a flow meter can accurately measure the fluid. Usually, it’s best to choose a flow meter with the greatest range available without compromising other components that are more critical.
There are many variables to consider when searching for the perfect flowmeter for your application. There. This does not even touch on the various options in different models. The best way to get the right meter is to get help with your search and team up with experts in the field. Experience matters.