Dražice NADO 300/20v6, NADO 500/25v6, NADO 750/35v6, NADO 1000/45v6 Operation And Installation Manua

Operation and Installation Manual

Accumulation Tanks

NADO 300/20v6
NADO 500/25v6
NADO 750/35v6

NADO 1000/45v6

Družstevní závody Dražice – strojírna s.r.o. (Works Cooperative - Dražice – Machine Plant, Ltd.)

Dražice 69

29471 Benátky nad Jizerou

Tel.: [phone], fax: [phone]

www.dzd.cz
[e-mail]

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1. Description

Accumulation tanks serve accumulation of excessive heat from its source. The source may be a

solid fuel boiler, heat pump, solar collectors, fireplace inserts, etc. Some types of tanks allow
combination of connecting even multiple sources.

The NADO type tanks serve accumulation of heat in the heating system and allow heating or
preheating of HSW (Hot Service Water) in an inner stainless tank. Incorporation of an accumulation
tank in the heating system with a solid fuel boiler allows an ideal run of a boiler at favourable
temperature during the boiler operation. The main benefit lies in the period of optimum operation (i.e.
with maximum efficiency) when the excessive unconsumed heat accumulates in the tank.

The tanks are manufactured in 300, 500, 750 and 1000-litre volumes. The tanks and tubular
exchangers are made of steel, without the inner surface treatment, the outer surface of the tank is
provided with a protective paint. Individual versions are additionally equipped with a tubular
exchanger and a buried stainless exchanger of 20, 25, 35 and 40 litre volumes, and two funnels G1½“

mm, with the possibility to install an electric heating element of TJ 6/4“ series with an extended

cooling compartment. The tanks are equipped with a removable 100 m thick insulation – polyester
foam (Symbio) and a lock.

The NADO type enables direct heating of HSW (Hot Service Water) in a stainless exchanger, or
its preheating for another water heater. Connection to a boiler usually allows direct HSW heating in an
inner stainless exchanger to the desired temperature whilst, on the contrary, connection to solar
collectors or heat pump only preheats HSW and another, e.g. electric, heater has to be used, in order to
complete heating of the water to the desired temperature, or final electric reheat has to be fitted in the
accumulation tank which is enabled by a TJ 6/4“ series electric heating unit with an extended
compartment of up to 6 kW output.

2. Designing the size and connection of ACCU tank to the heating system

An ideal size of the accumulation tank is designed by a design engineer, or a person sufficiently
qualified to design heating systems.
Product assembly must be implemented by an authorised person (confirmed in the warranty
certificate).

Notice: When putting into operation, water has to be filled first into the inner stainless HSW
exchanger and the operating pressure inside it has to be kept, only then heating water can be
filled into the outer accumulation tank, otherwise the product may get damaged!

The manufacturer explicitly emphasises the necessity of being particular in testing the tightness
of the heating circuit (radiators, piping joints, floor heating, etc.) with the connection of the
accumulation tank. No pressure grow above the maximum operating pressure of 0.3 MPa in
the accumulation tank heating water compartment may occur, if the heating system is
pressurised to higher than the maximum operating pressure, the inner stainless exchanger may
get permanently damaged!

No stop fitting can be put between the security fitting of the heating circuit and the accumulation
tank!!!