DS EN 14455:2005 Devices To Prevent Pollution By Backflow Of Potable Water - Pressurised Air Inlet Valves Dn 15 To Dn 50 Inclusive - Family L, Type A And Type B Defines the characteristics of pressurised air inlet valves of nominal size DN 15 up to and including DN 50 that are suitable for use in drinking water systems at pressures up to and including 1 MPa (