Diaphragm seals(Chemical Seals) are partitions used with pressure switches which prevent the measured medium from entering the pressure capsule of the pressure switch. Diaphragm seals solve many problems encountered in sensing, which are otherwise impossible to solve with only pressure switches.
protection of pressure switch from aggressive, highly viscous solidifying or crystallizing measured media
protection from high measured medium temperatures or fluctuations in temperature
protection from vibrations by coupling via capillaries
dead zone free sensing arrangements for particular hygienic applications
use of special materials or surface coatings of the wetted parts for special applications
In most of the cases, the common wetted parts and diaphragms are of SS 316. Alternate wetted materials that can be provided are: