Bourdon tube pressure gauge: Definition, Diagram, Working, Principle, Construction, Application, Advantages and disadvantages [with Pdf]

Are you in search of a Bourdon tube pressure gauge? then check this article where you will get detailed information about it.

What is bourdon tube pressure gauge?

What is bourdon tube pressure gauge?

  • Bourdon tube pressure gauge is a device used for sensing & measuring pressure which is invented by Eugene bourdon in 1849.
  • In this device, bourdon tube is a sensing element for pressure due to its elastic nature.
  • It can be worked for pressure limit up to 100000 psi.
  • It is a commonly used pressure gauge in many industrial applications.
  • It is generally oval or elliptical in cross-section with one end sealed & bend in C-Shape known as bourdon tube & another tube is for measurement of pressure.

Bourdon tube pressure gauge working principle:-

It generally works due to the elastic nature of the bourdon tube.

When oval or elliptical shaped tube is pressurized, It tries to attain the circular shape due to hoop stresses onto the wall of tube & due to this  C-shaped of tube also tries to straighten its shape.

Bourdon tube pressure gauge working principle

This moment of c-shape is magnified using gear sector & pinion arrangement.

Bourdon tube pressure gauge diagram:-

Bourdon tube pressure gauge

Bourdon tube pressure gauge construction:-

It generally consists of the following elements:-

A) Bourdon tube :- 

i) Bourdon tube is oval or elliptical in cross-section of thickness between 0.01 to 0.05 inches.

ii) It has one end sealed & another end open for pressure measurement & fixed into the socket.

iii) The socket has provision for attaching the gauge with equipment whose pressure has to measure.

iv) The material of construction for the bourdon tube is stainless steel, phosphor bronze, etc.

v) Generally bourdon tube is made in three shapes, C-shaped bourdon tube, Spiral shaped bourdon tube, helical bourdon tube.

vi) C-shaped bourdon tube is widely used in industrial applications. The C-shaped bourdon tube is bend in circular are over angle of 250 degree.

One end of the tube is sealed & connected to geared sector & pinion arrangement & another end is open & fitted into the socket.

B) Geared sector & pinion arrangement:-

i) The movement of the free sealed end is non-linear & smaller multiplication of movement of tip end is done by means of geared sector & pinion arrangement.

It is connected to the sealed end of the bourdon tube by means of an adjustable link.

C) Pointer & Dial :- The pointer is mounted onto the spindle of the pinion wheel. The dial is circular arc-shaped fitted onto the housing.

Working of bourdon tube pressure gauge:-

1] The open end of the bourdon tube is connected to the equipment or fluid. Transfer line whose pressure is to be measured.

2] When the fluid enters into the bourdon tube, hoop stresses are generated into the tube which tries to straighten the circular tube.
This allows the sealed end of the tube to move in a non-linear manner.

3] This movement of the sealed end is magnified by gear sector & pinion arrangement which allows the pointer to move onto the calibrated dial.

4] When the pressure is removed, the bourdon tube regains its shape & it allows the pointer to move on zero position.


Calibration of Bourdon tube pressure gauge is carried out by a deadweight tester.

Bourdon tube pressure gauge advantages:-

The Bourdon tube pressure gauge has following advantages

  • Simple in construction.
  • It can be used for the wide pressure range.
  • It gives high accuracy for high pressure.
  • It is less costly.
  • It gives very accurate results.
  • It has good sensitivity.
  • It gives continuous output.
  • It can be used for the vacuum measurement.

Bourdon tube pressure gauge disadvantages:-

The Bourdon tube pressure gauge has following disadvantages

  • It is subjected to hysteresis.
  • Slowly respond to changes in pressure.
  • It is sensitive to shock & vibration.

Bourdon tube pressure gauge applications:-

The Bourdon tube pressure gauge has the following uses

  • On the pressure vessel.
  • On the Air tank.
  • on the Gas pipelines.
  • on the material/Fluid pipelines.
  • Boilers.
  • Vacuum gauges.
  • High pressure reservoirs.
  • Fire extinguishers tank.  

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Pratik is a Graduated Mechanical engineer. He enjoys sharing the engineering knowledge learned by him with people.

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