A differentiation is made between diaphragm seals and inline seals
With the diaphragm seals, the pressure is measured via a flat convoluted diaphragm welded to a convoluted backup.
With the inline seals, the pressure is measured via a cylindrical diaphragm positioned in a pipe, and transmitted to the transmitter via the filling liquid.
The inline seal is a special design for flowing media. It consists of a cylindrical pipe in which a cylindrical diaphragm is embedded. Since it is completely integrated in the process pipe, no turbulences, dead volumes or other obstructions to the flow occur.
The following types of diaphragm seals exist:
• Pancake design, and pancake design with extended diaphragm (extension) to DIN or ANSI which are secured using a backup blind flange.
• Flush flange design, and flange design with extended diaphragm (extension) to DIN or ANSI which are installed by using holes in the flange.
• Sanitary remote seals, e.g. to DIN 11851, Cherry Burrell, APC connection, Tri-clamp connection, etc.
The sanitary remote seals are common designs in the food industry. Their design means that the measured medium cannot accumulate in dead volumes. The sanitary clamp present on the remote seal means that quick dismounting is possible for cleaning.
• Button diaphragm seal with male thread for screwing into tapped holes.
• Remote seals with customer-specific process connections.
The following types of clamp-on seals exist:
• Sanitary inline seals, e.g. to DIN 11851, Cherry Burrell, triclamp connection etc. The sanitary facility enables the seal to be removed quickly for cleaning purposes.
• Inline seals for positioning between DIN or ANSI flanges.
• Inline seals with customer-specific process connections.