DOMUSA TEKNIK LIGNUM NG 20, Инструкция по установке и эксплуатации

Страница: 15 / 44

13
5 TEMPERATURE RELIEF SAFETY VALVE
In order to avoid the temperature inside the boiler reaching damaging levels, this valve opens and lets
the mains water supply pass into the interior coil, thereby dispelling the heat in a fully reliable manner.
This occurs when, for hydraulic reasons or due to lack of electric current, the boiler cannot dispel the
heat it is generating.
This valve is obligatory in Lignum NG boiler installations.
5.1 Operating principle
The valve is regulated by the hot water from the boiler. If the water temperature is greater than
95ºC, the valve opens and lets the mains water through. This water moving in the coil absorbs the
boiler temperature and this prevents overheating and any damage to the boiler. The boiler
protection system corresponds with Standard EN 303-5.
5.2 Valve assembly
The temperature relief valve must be connected with free discharge to the safety heat exchanger
(in accordance with Standard EN 12828). The connection must not be blocked manually.
Furthermore, access must be granted to the heat protection mechanism and to the cleaning
inspection, once assembled. The minimum connection pressure for the safety heat exchanger is 2
bars. The nominal pressure of the valve is 5 bars.
The temperature relief valve is installed up-current of the coil (placed respecting the flow direction
according to the arrow on the coil). The mains water supply must be connected directly to the
temperature relief valve. The connection is threaded, type Rp 3/4" (DIN EN 10226).
IMPORTANT: It should not be possible to close the supply pipe so as to avoid any accidental
blockage.
IMPORTANT: The cold water pressure should not depend on the electricity supply.
IMPORTANT: The pipe must be thoroughly washed before installation.