Flush Diaphragm Pressure Transducers for Viscous Media

Common industries include food, pharmaceutical, environmental engineering (water, sewage, recycling), process, industrial and shipbuilding applications. 

Optional Ex ia intrinsically safe for gases and dust versions and food process versions are available on some of our models below.

All flush diaphragm pressure transducers can be supplied with digital displays and indicators, signal digitisers, telemetry systems, data loggers and acquisition equipment from our range of transducer instrumentation.  Calibration traceable to UKAS standards is available on all pressure sensors and systems.

What is a Flush Diaphragm Pressure Sensor?

A flush diaphragm pressure sensor has a diaphragm flush-mounted at the end of the sensor creating a flat surface across the end of the sensor. This is unlike standard pressure sensors where the sensing diaphragm is inside the pressure sensor within an open bore. There are also semi or quasi-flush designs where the sensing diaphragm sits very slightly back from the front of the pressure port, typically by just 1-2mm, and these offer the same advantages a fully-flush design.

As the sensing diaphragm on a flush pressure sensor is in direct contact with the pressure media, it enables the liquid to flow across it without risk of clogging the sensor. This makes it ideal to use in viscous or pasty media, where a recessed pressure port would be prone to blockages.

Plus, its flush diaphragm design allows for easy cleaning of all the surfaces making it perfect for sterile environments such as hygienic food applications or medial applications, where the sensor needs to be kept sanitary.

Oil-Filled Flush Pressure Sensors vs non-Oil-Filled Flush Pressure Sensors

Oil Filled Flush Pressure Sensors

Oil filled sensors have 2 diaphragms, one inside the cavity of the pressure sensor and one diaphragm flush mounted at the end of the pressure sensor. The internal cavity is filled with oil and when the external flush mounted diaphragm is exposed to the pressure media, the diaphragm puts pressure on the oil within the cavity. This in-turn puts pressure on the internal sensing diaphragm which converts the deformity into an electrical signal.
Temperature can have an effect on the oil inside the bore and several O-Rings are needed to ensure the oil does no leak out from the pressure sensor.

Non-Oil Filled Flush Pressure Sensors

These flush pressure sensors have only one sensing diaphragm and it sits flush with the end of the pressure sensor. The sensing bridge is on the internal side of the diaphragm and the external side is exposed to the pressure media. As the sensing diaphragm is in direct contact with the pressure media, the diaphragms tend to be thicker.

Advantages of a Flush Pressure Sensor

No Blockages

Easy to clean for sterile environments

Reliable in viscous media

Ideal in slow flowing pressure media without risk of clogging

Flush Pressure Sensor Applications

Food and Beverage Industry

Medical & Healthcare Industry

Sterile Environments

Slow Flowing Pressure Media – Chocolate, Syrup

Viscous Media – Slurry, Ink, Paint, Mud

Oil Drilling & Chemical Processes