Flanged seals with extended diaphragm S-T

The Aplisens S-T Flanged Diaphragm Seal with Extended Diaphragm is specifically designed to isolate pressure measuring instruments from process media that are high temperature, corrosive, viscous, or prone to crystallization on tank walls. The extended diaphragm design positions the separating diaphragm close to the inner wall of a multi-walled tank, ensuring accurate pressure and level measurement without direct contact between the process medium and the instrument.

The pressure signal is transmitted to the connected instrument through a manometric liquid filling the space between the separating diaphragm and the measuring device. This hydraulic transmission principle ensures reliable and accurate signal transfer even in the most demanding process conditions.

The S-T is available in both direct mount and remote mount configurations. The remote mount version uses a capillary connection, allowing the pressure transmitter or gauge to be located away from the process connection — ideal for high vibration or high temperature installations where the instrument cannot be mounted directly at the process.

Three manometric liquid options cover a wide range of operating temperatures. The DH fluid handles very high temperature applications up to 380°C in direct mount configuration. The DC fluid covers high temperature applications from -30°C to +315°C. The AK low temperature fluid covers applications down to -60°C for overpressure measurement.

The diaphragm, tube, and flange are manufactured entirely from 316L stainless steel as standard, providing excellent corrosion resistance for aggressive media. The S-T is fully compatible with Aplisens smart and analog pressure transmitters, differential pressure transmitters, and 63 mm and 100 mm pressure gauges. Special versions including radial capillary outlet and other DIN and ANSI configurations are available on request.