User manual HONEYWELL NK295C

[. . . ] NK295C Refilling combination Compact construction Product specification sheet Application The refilling combination serves filling and refilling of closed heating systems to DIN EN 12828:2003. It can be connected in accordance to EN 1717 constantly with the drinking water supply. [. . . ] The backflow preventer is a safety device in accordance with EN 1717 to protect systems against back pressure, back flow and back syphonage of non-potable water into service pipe, plants and equipments. The backflow preventer is separated in three chambers (inlet, middle and outlet chamber). If no water is drawn from the downstream system, the backflow preventer is in normal position. The up- and downstream check valves and the discharge valve are closed. If water is drawn from the downstream system, the backflow preventer is in flow position. The check valves up- and downstream are opened and the discharge valve is closed. L If the differential pressure between middle and inlet chambers is less than 10 % of the inlet pressure, the system disconnector moves into disconnect position (back suction). The inlet side backflow preventer closes and the discharge valve opens. The pressure reducing valve reduces the pressure on the inlet side (admission pressure) to the level of the desired pressure on the outlet side (outlet pressure) in individual cases. Spring-loaded pressure reducing valves work according to a system of force balance. If the outlet pressure (back pressure) drops as a consequence of drawing water, leading to the piston force dropping as well, the now greater spring force will open the valve. The outlet pressure is higher again until the balance between piston and spring force is once again achieved. [. . . ] Below two typical applications: · · Automatic refilling of the heating system Automatic refilling of system up to liquid catgory 3 in accordance with DIN EN 1717 · · · · EN0H-1548GE23 R0709 · Subject to change www. honeywell. com 3 NK295C Refilling combination Automation and Control Solutions Honeywell GmbH Hardhofweg D-74821 Mosbach Phone: (49) 6261 810 Fax: (49) 6261 81309 http://europe. hbc. honeywell. com www. honeywell. com Manufactured for and on behalf of the Environmental and Combustion Controls Division of Honeywell Technologies Sàrl, Rolle, Z. A. La Pièce 16, Switzerland by its Authorised Representative Honeywell GmbH EN0H-1548GE23 R0709 Subject to change without notice © 2009 Honeywell GmbH NK295C Refilling combination EN0H-1548GE23 R0709 · Subject to change www. honeywell. com 5 NK295C Refilling combination EN0H-1548GE23 R0709 · Subject to change www. honeywell. com 6 [. . . ]