A reversing valve for a compressed air membrane pump in which an equilibrium state of the main piston in the neutral position, leading to stoppage of the pump, is prevented by disposing the main system piston and the pilot system piston immediately adjacent to one another....http://www.google.fr/patents/US6382934?utm_source=gb-gplus-shareBrevet US6382934 - Reversing valve for a compressed air membrane pump
Reversing valve for a compressed air membrane pump
