HOW DOES A BOURDON TUBE MANOMETER WORK?

Operating principle
Selection criteria
Applications

INTRODUCTION
OPERATING PRINCIPLE
KEY FEATURES
CHOOSING MANOMETER
APPLICATIONS

GUIDE ON THE BOURDON TUBE MANOMETER

The bourdon tube pressure gauge is the type of most used pressure gauge in industry. It is characterized by using a curved bourdon tube, which gives it its name, which will be responsible fortransmitting the pressure to the gear, subsequently, the needle will provide the dial reading as it varies the pressure.

The bourdon tube pressure gauge is the industry favorite, and not for nothing, because its strengths are key: The pressure gauge offers high readings precision and accuracy, resistance to vibration (a common phenomenon in most installations) and simple maintenance.

In this article we will talk about its operating principle, selection criteria and its applications.

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OPERATING PRINCIPLE OF THE BOURDON TUBE MANOMETER

COMPONENTS

A. Inlet pipe

The bourdon tube manometer connects to the pipe, it is supported by the inlet tube which also holds the device to the process line.

B. Stationary end tube

The medium flows in the direction of the stationary end of the bourdon tube.

C. Bourdon tube

The pressure of the fluid is distributed throughout theC-shaped bourdon tube As a result of this pressure, the shape of C straightens up

D. Movement

The movable sector of the bourdon tube collects the pressure changes of the bourdon tube, the pivot link transmits movement to the gear sector.

E. Needle

The movement that occurs at the moving end is amplified by the gear system which results in greater movement of the indicator needle regarding a small change in pressure. Generally, the indicator moves from left to right in a circular path on a calibrated scale. A complete decrease in pressure will cause the bourdon tube to return to its original position.

DIFFERENCES BETWEEN A DRY AND A WET BOURDON TUBE

The bourdon tube manometer can be filled with glycerin (or silicone) or it can be dry, that is, containing only air.

Unfilled pressure gauges are more economical, less complex and withstand low temperatures better. However, this leads to less precision and also requires more frequent maintenance since the mechanism does not have the same resistance to vibration as it is not protected by liquid. In manometers filled with glycerin, the liquid lubricates the movement of the tube, protecting it from vibrations and sudden changes in temperature. These manometers, although more expensive, are more stable and accurate. .

KEY FEATURES

Let’s review the key features of bourdon tube pressure gauges High pressure range: Bourdon gauges can withstand high pressures, with typical pressure ranges up to 1034 bar (15,000 psi). High precision: The Bourdon tube manometer features a high sensitivity to pressure changes, which guarantees great accuracy and precision in the measurement. reading, normally within 2% of full scale. This makes them ideal for use in applications with critical pressure measurements, such as in process control and real-time monitoring systems. Moderate vibration and corrosion resistance: The vibration and corrosion resistance offered by the pressure gauge makes it the preferred choice of many industries for their pressure measurement applications. pressure. Ease of use: They are easy to install and require minimal maintenance. In addition, they are equipped with clear and easy-to-read dials and needle indicators. Low cost: Bourdon tubes are relatively inexpensive, making them a cost-effective option for many industrial and commercial applications.

CHOOSING MANOMETER

1. Diameter of the sphere

The size of the dial is chosen based on readability, space and precision. We have two models, the 6.3 cm one and the 10 cm one. More sizes are available upon special request.

2. Temperature:

The temperature of the fluid is directly related to the material of the internal organs, these are usually brass, nickel alloy or stainless steel. At high temperatures, the most recommended is stainless steel and filling with glycerin (-20ºC to 60ºC). When temperatures are low, it is recommended to fill the pressure gauge with oil or dry (-40ºC to 60ºC)

3. Corrosion resistance:

The nature of the fluid is very important, the internal brass organs are suitable for water, air and other non-aggressive gases. For aggressive fluids such as acid, ammonia and other corrosive chemicals, the most suitable pressure gauge is a stainless steel one filled with oil or glycerin, since glycerin also protects the needle from corrosion.

4. Vibration resistance:

An unfilled bourdon is suitable for low vibration applications, however, in the event of excess vibration a filled gauge absorbs shocks and pulsations allowing for easy and accurate pressure reading. In extreme cases, the pressure gauge may incorporate a shock absorber for pressure spikes.

5. Pressure:

There are 3 types of pressure to measure: Relative pressure, absolute pressure and differential pressure. Additionally, the operating range of the application must be taken into account. As a general rule, we will choose a pressure gauge with a pressure range twice the optimal service pressure. This way we ensure better performance.

APPLICATIONS

Bourdon tube manometers are present throughout the industry for measuring medium and low pressures due to their durability, accuracy and ease of use. These are the most common applications:

Oil and Gas Production: Bourdon tube pressure gauges are often used in the oil and gas industry to measure the pressure of fluids in wells, pipelines, boilers and other equipment.
Agriculture: Bourdon tubes are commonly used to measure fluid pressure in sprayers, irrigation systems and other agricultural equipment
Power generation: They are used in power plants to measure the pressure of steam, water and other fluids to generate electricity.
Water treatment: They are used to measure water pressure in water treatment plants, ensuring that water is pumped and treated at the correct pressure.
Pneumatics and hydraulics: Used in pneumatic and hydraulic systems to measure the pressure of air and liquids in cylinders, pumps and other components