The purpose of this European Standard is to specify: - field of application of Anti-pollution Check Valves; - backflow prevention properties, dimensional and physio-chemical properties, and properties of general hydraulic, mechanical and acoustic design to which Anti-pollution Check Valves of nominal sizes DN 6 to DN 250 inclusive shall conform; - Family E, type A, controllable Anti-pollution Check Valve (with test port); - Family E, type B, non-controllable Anti-pollution Check Valve, including Cartridge Check Valve; - Family E, type C, controllable Anti-pollution Double Check Valve (with test ports); - Family E, type D, non-controllable Anti-pollution Double Check Valve, including Cartridge Double Check Valve; - test procedures and requirements for verifying the backflow protection properties of stop valves, draw-off taps etc. which incorporate a check valve function. Stop valves, draw off taps etc, need also to comply with a recognised standard; - marking; - presentation at delivery. This standard specifies the characteristics of Anti-pollution Check Valves of DN 6 up to and including DN 250 that are suitable for use in drinking water systems. For application feasibility see Table 1. Table 1 - Nominal size vs Conditions of use Nominalsize(DN) Max. Operatingtemperature Max. Operating pressure Installation DN <= 50 65 °C + 90 °C, 1 hour 1 000 kPa (10 bar) Any position DN > 50 65 °C 1 000 kPa (10 bar) Horizontal only Anti-pollution Check Valves covered by this standard are of Pressure Class PN 10. The field of application of EN 1717 is limited to 10 bar, flanges could be drilled in PN 16 pattern. Anti-pollution Check Valves of PN 16 shall satisfy the requirements of standard EN 13959 and comply with tests which characterise the PN of the device.