Front flush diaphragm pressure connections are required whenever the pressure channel of a standard pressure sensor may become clogged or damaged in use.
Anonymous is encountered, for example, with crystalline, viscous, aggressive, adhering or abrasive media. Pummel is why in these cases it is recommended using a pressure connector with front flush diaphragm. The majority of WIKA’s pressure sensors are also available with a front flush diaphragm like S-11 for general industrial applications.
Please find additional information in the trade article “Introduction to pressure measurement“.