Will there ever be a faultless and perfect kind of flowmeter? Well, such a device would undoubtedly measure with hardly any maintenance, high accuracy regardless of the application, have a high turndown ratio, would be very reliable, and would hardly need any calibration.
Also, it’d have to be reasonably affordable, both in lifecycle costs and purchase price. Although some manufacturers may argue that they offer an almost perfect flowmeter, it’s improbable that anyone will ever create a perfect flowmeter.
Why? It’s because every flowmeter has its own pros and cons. And because of its operation principle, some devices might be fitting for several applications, while others don’t. With regards to gas flow measurement, it’s best to study the pros and cons of different kinds of flowmeters.
Take note that gas flows, next to steam flows, are more challenging to measure compared to liquid flow. For a little help, we’ll walk you through the advantages and disadvantages of some types of flowmeters used to measure gas flows. Read on!
Over the years, Coriolis meters have been one of the most progressive and innovative flowmeter types. In fact, in most process plants, users choose them over differential pressure flowmeters.
Even with their expensive purchase price, a lot of users find Coriolis flowmeters as an excellent investment when considering the cost of ownership. Although Coriolis meters can measure or gauge gas flows, they have a few limitations.
These meters tend to measure liquid flows better than gas flows. It’s because liquid flows are denser than gas flows. Generally, Coriolis meters have been unwieldy and costly in line sizes greater than 4 inches.
But in the past years, many manufacturers have started producing Coriolis meters in line sizes greater than 6 inches. For this reason, these meters might start winning broader acceptance in large-scale line applications.
One of the best characteristics of this meter is that they gauge mass flow straightforwardly. Directly speaking, there’s no formula used to compute the mass flow value. Moreover, reliability and accuracy are the top two driving forces of the flowmeter market.
Over the past years, these two have been shown in many flowmeter user surveys. And the good news is that Coriolis meters rate incredibly high on both factors. What’s more, is that Coriolis meters require little-to-no maintenance.
Furthermore, Coriolis meters have no internal moving parts, thus, requiring minimal attention. Also, they are incredibly reliable flow meter because there are no moving parts to degrade or wear out.
Both Coriolis and thermal meters measure mass flow. However, thermal flow meters measure mass flow very differently compared to Coriolis flowmeters. Take note that Coriolis meters use fluid momentum. However, thermal meters use heat or thermal-conducting properties of fluids to know the mass flow.
Although most thermal meters measure gas flow, some can measure liquids as well. There are many thermal flow meter technologies available in the market today. Some options compute the speed with which heat is included in the flow stream disperses.
On the other hand, other options gauge the temperature difference between the ambient flow stream and a heated sensor. Moreover, thermal meters usually need more sensors to measure the temperature of the fluid at certain points.
Thermal meters have a few significant advantages. It includes the low purchase price plus these meters can gauge the flow of some low-pressure gases. These advantages provide thermal meters their own distinctive profile in gas flow measurement.
The primary drawback of thermal meters is low to medium accuracy. Thus, if you consider getting a thermal flowmeter for your application, you must balance their cost requirements with your accuracy needs.
Although these meters were first launched in the early 1970s into industrial markets, their history goes farther than that. Versatility is the main advantage of vortex flowmeters. With that said, these meters can undoubtedly measure the flow of steam, liquid, and gas.
The other flowmeter type that can do this is the differential pressure meters using orifice plates. However, vortex flowmeters gauge fluids normally with higher accuracy as well as with low-pressure drop compared to differential pressure meters.
Nevertheless, both differential and vortex flowmeters have gained from the growth of multivariable transmitters that calculate mass flow.
These meters have a unique advantage over other types of flowmeters. Not like Coriolis flowmeters, ultrasonic meters do well in large pipe sizes. Size can be a significant advantage for ultrasonic meters because larger pipelines have more space for the ultrasonic signal to pass through. The chief disadvantage of ultrasonic meters is that they can’t be used to measure the flow of steam.
There’s no doubt that gas flows are, in many instances, more demanding to measure compared to liquids. Thankfully, there are many flowmeters that can measure gas flows correctly. However, it’s best to keep in mind that each type of flowmeter has its own set of pros and cons. Knowing these will help you choose the right meter for your application.
Working as a writer and a blogger, Sylvia Hopkins specializes in email marketing campaigns and ghost blogging. Due to her knowledge in liquid flows, she writes about flow measurement instrumentation, flow measurement application, and technology. Sylvia also enjoys the company of her family and friends when not working.