HD Preventer HD N9 & HD NLF9

Double check valves/aerators with intermediate connection to the atmosphere. These non-return valves prevent the return flow of polluted water into the drinking water network and are suitable for laboratory taps, among other things. The HD N9/NLF9 must be placed vertically.

 The construction is the same as that of the HA S8C, but a second check valve is installed on the discharge side. The HD N9 is suitable for mounting under continuous pressure. The HD NLF9 is suitable for mounting after the shut-off valve, of which the downstream pipe section must be flexible and demountable, not continuously under pressure.