The SISTO-C 2/2-way diaphragm valve is built around a single defining principle: only two components ever touch the process fluid — the forged stainless steel body and the chambered diaphragm. Everything else (actuator, spindle, bonnet) is hermetically isolated. This makes the valve inherently dead-space-free and fully self-draining, properties that matter most in sterile process environments where residual fluid pockets create contamination risk.

How does the chambered diaphragm seal work?

Unlike a conventional weir-type diaphragm valve where the diaphragm presses against a raised seat, the SISTO-C uses a chambered membrane — a closed diaphragm element that forms a sealed cavity around the flow path. From DN 65 upward, a metallic spiral support distributes the closing force evenly across the diaphragm face. The result: longer diaphragm life, higher permissible operating pressures (up to PN 20), and no leakage path to atmosphere even if the diaphragm wears — the chamber contains any weepage until scheduled replacement.

What makes this valve suitable for aseptic service?

The forged 316L body is available with electropolished surface finishes down to Ra 0.25 μm, meeting pharmaceutical surface requirements. The self-draining geometry — with the drain angle laser-marked on weld ends — ensures complete drainability after CIP cycles. Certifications include FDA CFR 21 177.2600 for food contact, USP Class VI for pharmaceutical biocompatibility, and EU 1935/2004 for materials in contact with food. TA-Luft compliance confirms fugitive emission control for chemical and sterile barrier applications.