The diaphragm seal is a pressure-transmitting, diaphragm-type device.
The pressure signal is sent to the cooperating pressure measuring device (pressure transmitter, pressure gauge) through manometric liquid filling the space between the separating diaphragm of the seal and the pressure measuring device.
The diaphragm seal task is to isolate the pressure measuring device from damaging impacts caused by either medium or installation:
Low or high temperature, increased viscosity, impurities
Tendency to crystallisation on the tank walls
Vibrations of the installation (remote diaphragm seal)
The flanged diaphragm seal with extended diaphragm is typically applied to measure the pressure or level of the media in a multi-walled tank, where the separating diaphragm should be placed close to the inner wall of the tank.