Types of Bourdon Tube

October 26, 2022
bourdon tube with exposed wire

The most common mechanical pressure gauges are variations of the Bourdon tube. Their pressure element is similar to an elastic spring, a c-shaped, bent tube with an oval cross-section, thus the name “Bourdon tube.”

What are the Types of Bourdon Tube?


In the oil and gas business, this instrument is used more frequently than any other gauge pressure indicator device. Within the range of its elastic properties, the gauge follows Hooke’s Law. The fluid pressure exerted on its free end will cause it to move.

The Bourdon tube is based on the fundamental premise that a tube can be bent to adapt to different pressures on the inside and outside. If you apply pressure on the inside of the tube, it will straighten and then go back to its original shape when you release the pressure.

This measurement concept is used for pressures between 0.6 bar (9 psi or 60 kPa) and 7000 bar in the real world (105,000 psi or 700,000 kPa). For pressure readings below 60 bar, a C-shaped tube is typically utilized (900 psi, or 6000 kPa). Bourdon tubes that wind and twist are used to measure at greater distances.


To create a Spiral Bourdon Tube, a flattened metal tube is spiral-wound into multiple turns rather than a single C-bend arc. The total rotational motion of the spiral equals the rotational motion of each of its C-bend arcs taken separately.

Consequently, a bourdon tube with a C bend results in more directional change at the tip. Most its deployments involve working with relatively low pressure.


The helical is a bourdon tube that has been spirally wrapped. To convert the tip movement into a circular motion, a central shaft is mounted inside the helix adjacent to its axis and attached to the tip.

What is Bourdon tube used for?

A bourdon tube is a pressure gauge that displays the current pressure reading to the user and helps prevent dangerous spikes and drops in pressure. The Bourdon gauge is just one type of pressure gauge, however, it is the most widely used.

Gauge pressures between 0.6 and 7,000 bar can be measured with a Bourdon tube pressure gauge. One of the greatest advantages of this kind of pressure gauge is that it doesn’t require an external power source to function.

What is Bourdon gauge pressure?

The Bourdon pressure gauge is a gauge that measures pressure by measuring the expansion and contraction of a metal tube that is either coiled or semicircular in shape. This type of tube can be either straight or curved. We are able to see why this is the situation by keeping in mind the presumption that a distorted tube, when subjected to an amount of pressure that is sufficient, would return to its original circular shape.

Mid-West Instrument

Midwest Instrument is an industry leader in manufacturing and designing differential pressure gauges, transmitters, and switches. With over 60 years of experience, you can rest assured that we have all the skills, time, equipment, technology and workforce to get you the best products in the industry. Feel free to contact us to learn how our products can help you today!