A flow meter or sometimes called a flow sensor is a device that is used to measure the nonlinear, linear, volumetric, or mass flow rate of a fluid or gas. There are different kinds of flow meters like variable area flow meters, but the goal stays the same; to get the most accurate measurement possible for different situations.
There are certain factors you should consider if you decide to use a flow meter. The personnel involved with the process should be familiar with handling and maintaining the flow meters used. Two of the most important things that your staff should know is the calibration and the functionality of flow meter.
One of the usual mistakes that some people make is that they tend to use flow meters because it is the cheapest way to measure certain liquids and gases. But they don’t pay attention to what flow sensors they should apply for this specific situation.
It is crucial to make sure that the engineer has approved of the whole thing, and with that, you are good to go.
Taking the first step
The first step in choosing the right flow meter is to know if the measurement should be continuous or made in totality. Also, you should consider if you need the results remotely or locally. If you choose to have it remotely, ask yourself if you want the transmission to be digital, analog, or shared.
If you decide to have it shared, you should know the required data-update frequency. Once all of these questions are answered, determining the properties and the flow characteristics of the fluid and the piping where the specimen should be measured should take place.
Fluid and flow
The fluid and its characteristics like temperature, pressure, allowable pressure drop, maximum permissible temperature, viscosity, density, conductivity, and vapour pressure should be jot down. Taking notes on how these variables usually interact is also essential to predict unexpected situations. Furthermore, other properties of the fluid-like toxicity or different hazardous nature should be made known to avoid any accidents.
Pressure and temperature
Determining the expected maximum and minimum pressure should be determined, as well as the varying temperature of the fluid as well as the standard operating variables that are important in choosing the right flow meter.
The possibility of a reverse flow, the chances of it filling the pipe, and the formation of slugs, pulsation and aeration, and other variables changing in numeric values are needed and should be made known to allow smooth and safe maintenance.
Pipe and Installation
There are certain factors to be considered as to where and how the pipes should be installed and where the flow meters are found. The size, pipe material, the schedules measurements and maintenance, accessibility, the flag-pressure rating, valves, regulator, and the length are just some of the elements to be considered when specifying the whole process.
The engineer in charge of the entire thing should be notified if there are magnetic reactions in the area, as well as the vibrations, pneumatic power, and other safety hazards that can occur during the measurement. These requirements are required to ensure the safety of the personnel as well as the success of the whole thing.
In measuring liquids, make sure the flow meter is full of liquid at all times as gas and vapour can alter the volume and will significantly affect the accuracy of the measurement. On the other hand, gas and vapour service, the opposite should be done. Be sure that the flow meter is full of gas or vapour, as liquids can significantly alter the accuracy of the measurement.
Disturbances could occur upstream or downstream or both at the same time, specifically in control valves and pipe elbows. These disturbances can alter the accuracy of the flow meter and will give off a wrong measurement. See to it that the control valves are located downstream as not to have the flow disturbances be directed to the flow meters as they are located upstream of the pipes. Also, ensuring that there are enough straight pipes for the specimen to run through is essential to minimize or avoid flow disturbances altogether during the process.
Moreover, when having a two-phase flow such as liquid/gas or liquid/solid, make sure the flow meters can be plugged or completely stopped. These types of flow can alter each of their volumes, making it difficult to have an accurate measurement.
There are specific factors that you should consider before picking the right flow meter that will be used, as well as for instructions on how to use them properly and efficiently. Taking note of all the properties of the specimen is essential to make sure the measurement is always accurate. Always remember that the safety of the personnel involved and the success of the whole operation is paramount.
Slyvia Hopkins is a writer and blogger. She can be found writing content about flow measurement and technology. Sylvia enjoys her free time seeing live music, biking, and fishing.