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SCOTCH type water boilers

Hot / Superheated water boilers product range: • PRN /W • SCOTCH /W • ARTO HN



Reverse flame tube boilers for hot / superheated water.

Three-pass flame tube boiler for hot and superheated water.

Capacity range: 35.000 – 3.000.000 kcal/h High efficiency.

Range Capacity : 500.000 – 8.000.000 kcal/h Durability.

The flame produced by the burner develops in the furnace. Produced flue gases return towards the front and enter the tube nest through the smoke chamber in the door. On leaving the tube nest, flue gases are collected in the rear box and transferred to the chimney.

These boilers have a three flue gas pass layout, the first of which passes through the furnace. Produced flue gases are reversed in the rear wet reverse chamber and return towards the front through the tube nest of the second pass.In the front smoke chamber flue gases are reversed again, enter the tube nest of the third pass and are then collected in the rear box and transferred to the chimney.

The bottom of the boiler is arched and not flat as is common in the market. This geometry ensures greater tolerance to mechanical stress and better heat transfer. High water volume in combination with a sophisticated design ensures good water circulation and prevents from scaling. Insulation with high density mineral wool protected with stucco aluminium cover sheets.


The gas reversing chamber is water rinsed, while its design allows not only the smooth reverse of flue gases towards the tubes of the second pass but also its easy visitation when it needs to be cleaned or serviced.


ARTO HN TYPE WATER-BOILERS Hot water boilers with an integrated stainless steel water heater.

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Capacity range : 50.000 – 500.000 kcal/h A compatible burner is adapted to a steel made combustion chamber. The flue gasses pass through fire tubes and heat up the DHW which is inside a stainless steel tank with corrugated walls. The fact that the DHW tank is hanged from the top bottom of the boiler ensures that there is no accumulation of scaling. This plays a vital role to the long life of the boiler.

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Flue gases towards the chimney Metal casing Domestic Hot Water (DHW) Metal Base Furnace Insulation Primary fluid (central heating water) 4



ARTEMIS economizers can increase the boiler efficiency by 5-7% using the flue gas energy that is released unexploited in the atmosphere. This energy builds up the temperature of the return flow water so the efficiency of the boiler can reach 96%. ARTEMIS economizers are especially designed and can be applied to both new and already existing boilers. • Finned tubes of high quality • Large inspection openings • Easily removable and pre-mounted to the flue gas rear chamber. When the fuel used is heavy oil, then the flue gases except for their high content in soot usually also contain unburnt masses which are particularly damaging for the atmosphere and the environment. A solution to this problem are soot accumulators, which through a special layout of fins retain a big part of the soot and unburnt masses and as a result the gases driven to the atmosphere are cleaner. Because heavy oil has high content in sulphur which is particularly corrosive the soot accumulators are made of stainless steel sheets.


The electrical control panel of the boiler consists of the following:

In most cases the investment of an economizer can be paid back in

less than a year time!!

General switch Burner switch Circulator thermostat

Thermostat for burner function Safety Thermostat for burner Thermometer

ADVANTAGES For all traditional oil and gaseous fuels Low fuel consumption Easy cleaning and maintenance High water volume Wet back High efficiency Sophisticated design High quality insulation Durability Superheated water boiler type PRN/HW



The rear gas chamber is dismountable in all sizes of PRN/W and SCOTCH/W type boilers.This makes maintenance and service a simple procedure.

One of the most important characteristics of a reverse flame boiler is its door support.

There in the flue gas chamber is also welded the flue gas connection duct to the chimney. The connection is made by a carefully designed coupling. In big sized SCOTCH/W boilers (over 3.000.000 kcal/h) the rear smoke gas chamber is welded to the boiler plate. However, it bears two spacious ports which allow the cleaning of the boiler as well as easy access to the rear boiler plate. The flue gas side inspection opening bears a fireproof lining suitable for temperatures up to 1900 °C, which ensures easy access to the furnace.

In most cases a ‘’hanging’’ of the door is observed and as a result maintenance becomes hard and o‘en a leak of smoke gas appears. The support of the door of the ARTEMIS PRN/W boiler is very carefully designed. Despite its particularly big weight, it can be closed even by a little child and no sign of hanging will ever appear. Smoke gases coming from the tube nest are reversed through the hollow in the door insulation. Special insulating materials cut radiation losses to an insignificant minimum.

Alternatively the flue gas connection duct can be flanged and also arranged on the top PRN/W



T +30 2310 519708

F +30 2310 510794


+30 2310 529783


P.O. Box 1226, GREECE

+30 2310 799659

PRN/W - Reverse flame tube boilers for Hot/Superheated water.  

Reverse flame tube boilers for Hot/Superheated water. PRN/W type water boilers are suitable for all traditional oil and gaseous fuels.