Non-return valve i.e. flutter valve, has stopping element whose stop surface extends parallel to bending line of spring tongue in deflected state, where elastic deformation of tongue is limited by striking tongue against stop surface

摘要

The valve has a spring tongue (10) i.e. spring plate, clamped at one end and elastically deformed to open/close an aperture (16), based on pressure difference on both sides of the aperture. A stop surface (26) of a stopping element (14) extends parallel to a bending line (28) of the tongue in a deflected state, where elastic deformation of the tongue is limited by striking the tongue against the surface. A mechanical damping layer e.g. plastic or elastomer layer, is arranged between the tongue and the stopping element. The stopping element is formed as a support for the tongue.