Stop Silent® – Non-return valves…

Medusa Stop Silent

…moves like a jellyfish.

Valves for Every Application

Stop Silent® check valves are different to common valves:

No moving parts

No electronics

No wear-and-tear




low maintenance


durable, up to 50 years

No moving parts>low maintenance
No electronics>fail-safe
No wear-and-tear>durable, up to 50 years

The Jellyfish

The Stop Silent check valve’s membrane moves like a jellyfish. It silently deformes to let liquides pass in one direction and withstands strong pressure in the opposite direction.
Die Membrane liegt in unbelastet im gelochten Stützkegel und die Dichtlippen liegen auf der Innenfläche des Kegel und verunmöglichen den Rückfluss.

The Stop Silent Product Line

For waste water up to 0.5 Bar

  • Easy and quick to install without structural adjustments
  • Always closed and active against backwater

  • No mechanical moving parts and no electronics for a longer lifetime

  • Also serves as flat check valve (against frogs) and anti-odour valve

For clean media up to 16 Bar

  • Consists of two components only (membrane and support cone)
  • No moving mechanical parts, no electronics
  • Gentle closing, no water hammer
  • Low pressure drop
  • Low maintenance
  • Long-lasting

Lasso Technik AG

Niklaus von Flüe-Strasse 33

4059 Basel


Phone: +41 61 331 40 90

Fax: +41 61 331 42 76