June 17, 2024

Rotameter: How does Rotameter works and its functions?

Today, you can easily monitor the volumetric flow rate of gases and liquids. All you require is the right Rotameter that suits your application. Are you running a business that involves liquids and gases? Getting it right when it comes to flow rate can save you from damages or losses resulting from a high flow rate or even a low flow rate than the intended limit.

You will find many types of Rotameter in the market. Not all Rotameter will be suitable for the fluid or gases you seek to monitor. That’s why it will be crucial to understand every type of Rotameter and how each works. After doing that, rest assured to get the best flow meter device that guarantees accurate results.

How Rotameter works

A Rotameter operates based on a variable-area principle. As the fluid or gases flow through the Rotameter, it raises afloat inside a tapered tube. When the float is raised, it increases the area through which the fluid flows.

The float rises until it hits a stable level where force generated by the flowing fluid or gases plus buoyancy is equal to the gravitational force. Any change of flow rate can upset the created balance. When that happens, the float will move down or up until it can reach a position where the forces are in balance.

Besides, there will be a low-pressure drop across the float and maintains that low level while the flow rate changes. A Rotameter floater responds to a change in the flow rate in a linear manner. Generally, a 10 to 1 flow range will be the standard.

The position of a Rotameter float depends on gravity. That requires you to mount your Rotameter vertically and oriented with a wide end of the taper at the top. You should also keep in mind that when the flow stops, the float sinks to the bottom of your Rotameter due to its weight.

When reading the flow rate, you just look at the graduated sale found on the side of your Rotameter. The scale is calibrated to a particular fluid with known gravity. Weigh of the fluid or the specific gravity affects the reliability and accuracy of the Rotameter.

Functions of a Rotameter

1. It can be applied in the process analysis

Are you a process analyzer? You won’t avoid measuring a target analyte in a process stream. In-process analysis, sampling is a great issue. A plugged sampling system may cause a big problem and even losses. It may also lead to unplanned maintenance.

But with a Rotameter, you will not have to worry much. It will monitor analyzer sample flow in a continuous process. Any time flow begins to go down, which is an indication of plugging, you will get signals, and you can schedule maintenance to eliminate the problem. That prevents the analyzer from being starved of the sample.

2. Monitoring of lube oil and coolant control flows

You may deal with large rotating equipment. That needs a reliable flow monitoring of several fluid supplies to ensure safe and efficient operation. It can be dry gas seal gases, coolants, and lubrication fluids. So, with a metal-tube Rotameter, you may use well monitor coolant flows and lube oil. On the other hand, a glass-tube device is the most suitable to ensure the smooth flow of dry gas seals.

3. You can use a Rotameter on offshore platforms

Have you ever encountered extreme conditions on offshore platforms? That’s where you require a Rotameter! You may use such a device to inject exclusive fluids into a high-pressure extraction fluid as a way of preventing corrosion or extraction-fluid freezing. It may also be done to add lubrication.

For all those situations, a Rotameter helps to carry out local monitoring to improve the overall process yield. But you may have limited choices when it comes to flowmeter since extraction occurs under very high pressure. However, a Rotameter will be a great option since it is simple, reliable, proven, and available for use where high pressure is needed.

4. Purge application

Liquids or purge gas maintains the process line very clear. That is achieved by forming a shielding gas inside a contained welding application or positive pressure.

Pros of a Rotameter

  • It can offer accurate results repeatedly under the same process conditions
  • Since it has a low-pressure drop, you can install your Rotameter in many places in the process
  • A Rotameter is simple to install and maintain.
  • It is a cost-effective device.
  • When using a Rotameter, you can observe and see the process
  • No external power is needed to run a Rotameter which saves the cost of energy.
  • Rotameter isn’t that expensive and offers reliable and accurate results.


You may be looking for a cheap yet effective solution to the flow metering issue. Don’t look far since a Rotameter is reliable whether you are dealing with liquids or gases. Ensure you get your Rotameter from a reliable supplier.

Naman Modi

Naman Modi is a Professional Blogger, SEO Expert & Guest blogger at NamanModi.com, He is an Award Winning Freelancer & Web Entrepreneur helping new entrepreneur’s launches their first successful online business.

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