A.O. Smith EQ 380 G, EQ 280 G manual General, Description of the appliance

1.GENERAL

1.1Description of the appliance

Construction of the water heater is in accordance with the European standard for gas heated water storage heaters for sanitary application (EN 89). The appliance thus meets the European Directory for Gas Appliances and is therefore entitled to carry the CE- marking. It is an open flued appliance without ventilator and with a flue gas down draught safeguard (category B11BS). The water heater is suitable for a maximum working pressure of 8 bar. The water-heater tank is manufactured from low carbon sheet steel and is glass-lined on the inside. In addition the tank is fitted with a sacrificial anode as an extra protection against corrosion. A thick PU-insulation layer covered in a steel jacket reduces unnecessary heat loss. When the appliance is filled with water it continuously is under water pressure. As hot water is drained from the tank, cold water is added immediately. Four flue baffles has been placed in the flue tube to improve heat transfer. The flue gasses pass their heat on to the water by means of radiation and convection. The flue gasses are guided to the chimney via the draught diverter. The exhaust of the flue gasses is realized by natural thermal draught (see drawing 1).

Dead legs on a hot water installation are undesireable. Where possible they should be avoided. Where the inclusion on the system of a dead leg is unavoidable the following restrictions should be applied:

-for pipes not exceeding 19 mm. inside diameter; maximum lengh of dead leg permitted 12.0 metres;

-for pipes exceeding 19 mm. but not exceeding 25 mm. inside diameter; maximum length of dead leg 7.5 metres;

-for pipes with an inside diameter

exceeding 25 mm. maximum dead leg 3.0 metres.

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