The primary elements used for measuring pressure are:
- Bourdon tube.
- Diaphragm.
- Capsule.
- Bellows.
- Pressure Springs.
The above are known as elastic deformation pressure elements.
Type of Bourdon tubes.
- ’C’type.
- Spiral.
- Helix.
Diaphragm: The diaphragm is best suited for low pressure measurement.
Capsules : Two circular diaphragms are welded together to form a pressure capsule. Material Used: phosphor bronze, Ni-spanc stainless steel.
Bellows : Bellows is a one - piece, collapsible, seamless metallic unit with deep folds Formed from very tin walled tubing. Material used: Brass, phosphor bronze, stainless steel. Used for high Pressure.
Pre.spring: Pressure springs of helical or spiral shape used for measuring high pressures.