Diaphragm pressure gauges

Diaphragm pressure gauge - Precise pressure measurement for liquids and gases

Diaphragm pressure gauges with radial connection are ideal for measuring various liquids and gases. Thanks to the large surface area of the corrugated diaphragm, you can read the pressure reliably. Our range includes robust models made of gray cast iron as well as chemical-resistant versions made of stainless steel with a safety disk. Find out more about the functionality, applications and advantages of this measuring technology here.

Applications of the diaphragm pressure gauge

Diaphragm pressure gauges with radial connection are suitable for liquid, viscous and gaseous media where contact between the medium and the measuring element must be excluded. The chemical version can also be used in more aggressive environments. These pressure gauges are used in the chemical, petrochemical, oil and gas industries as well as in energy technology and are especially designed for low pressure ranges.

How the diaphragm pressure gauge works

A diaphragm pressure gauge uses a flexible, thinly corrugated metal diaphragm that is clamped or welded between two flanges. This diaphragm separates the medium from the measuring system and thus ensures that the pressure acts exclusively on the diaphragm. If the diaphragm is loaded by the measuring pressure, it bends in proportion to the pressure. A transmission rod transfers the movement of the diaphragm to the pinion of the pointer mechanism, which enables the pointer to move on the circular scale.

Overload protection

The design of the diaphragm and housing ensures that the pressure gauge is reliably protected against overload. If the pressure exceeds the maximum permitted value by more than one percent, the diaphragm supports the upper part. The standard model already offers five times the overload protection in relation to the full scale value. Versions with higher protection are also available on request.

Performance of the diaphragm pressure gauge

The measuring unit can measure positive pressure up to 40 bar and negative pressure up to -1 bar for gases, vapors and liquids. The accuracy of the display is between 1.6 and 2.5 percent of the maximum measuring range.

Permissible temperature ranges

The ambient temperature of the pressure gauge should be between -20 and +60 degrees Celsius, while the medium may be up to 180 degrees Celsius. For special versions, the upper limit can even reach 350 degrees Celsius.

Protection from aggressive media

Special materials such as tantalum, polytetrafluoroethylene or Hastelloy provide additional protection for the diaphragm against aggressive media. The housing and wetted parts made of stainless steel meet the high requirements for resistance to corrosive substances.

Plate spring pressure gauge with open measuring flange

For highly viscous, contaminated or solids-carrying media, a diaphragm pressure gauge with an open connection flange is recommended. This design prevents blockages in the pressure channel and enables easy cleaning of the pressure chamber thanks to a flushing hole.