Sprache / Sprog / Språk :                  




Introduction to Compact Water-Tube Steam Boilers


contact                                main menu


Boilermaker AB&CO (Copenhagen, Denmark)
Models Small Vertical Types
Larger Horizontal Types
Steam Capacities 70 - 3,000 kg/hour
Working Pressures 3 - 190 bar gauge
Energy Source
Natural gas, LPG, bio-gas,
light and heavy fuel oil,
- and combinations hereof.
Utilisation of Energy

(depends on working loads and steam pressures. Designs for ultra high efficiencies on request)
Efficiencies (based on LCV) :

90 - 92% (basic boiler design

95 - 97%
an economizer i.e. extra flue gas cooling e.g. for water heating)
The Model General Description
Design Horizontal & Vertical Options
Data & Dimensions Total Data Survey - For Guidance Only
Steam Boiler System Typical Flow Diagram
Special Optional
Design & Features
Mobile Steam (skid/container/trailer)

High Pressures (high temperatures)

Clean Steam (sanitary steam)

Economisers (flue gas heat recovery)
Steam Boilers
Steam Generator Range with Specific Data

All THE STANDARD boilers - range & data
Introduction to
Other Steam Boilers
Fire-Tube Steam Boilers (for oil/gas)

Electric Steam Boilers
(electrical heating

All THE STANDARD boilers - range & data
Heating Methods Steam Generators VS Steam Boilers

Thermal Fluid VS Steam
Flue Gas Data How to Calculate - Flue Gas Properties
Chimney / Flue Gas Design & Lay-out - Stack Sketch
Assistance Design & Trouble Shooting

Service & Supervising

Steam table

data sheet




assistance & tools
of references


The steam gewnerators are industrial steam boilers for small steam capacities. The special compact water-tube design gives a small internal steam/water compartment.

Steam generators offer fast start-up, modest heat losses during hot stand-by (idle) and an extreme safety during operate (no risks for steam explosions). Even though the investment is not the lowest when choosing the high quality models, the special technical features ensure that the long term costs are still much lower.



150 - 1200 kg/h

PI-diagram for your
choice in scope of supply

  power ratings
150 - 1200 kg/h



contact                       main menu      








Easy & Safe to Operate
- normally very few or no requirement  on installation, start-up an operation from national authorities (depending on actual state law and regulation).
Rapid Start-Up
- from cold condition, which also means no energy consumption when no steam output.
- no large water volume thus small outer dimension. Easy to fit in
almost everywhere
Horizontal or Vertical Design ?
- even more flexible to fit into an existing arrangement. Choose between the
Horizontal or Vertical Design.
Environmental & Customised Design
- Efficiency means low fuel consumption,  low CO2 emission and low NOx emission. Thus this gives low operational cost and an environmental (green) profile. A customized design gives different options in this aspect - depending on the investment.
Heavy Duty Design
- Rigid design and constructed to withstand extreme pressure and temperatures - up to 350°C and 190 barg on request (as delivered for a test bench for safety valves for nuclear submarine)
Price Attractive
- both in purchase, but especially in operation. Particular supreme economy at small operation times with periods with no or low steam rates.
Approved & Proven  
- by the most demanding customers and authorities worldwide. The basic design is 'battle proved' - the first units was put into service by TT BOILERS in the 70ties.

Special Optional Features
>  Clean Steam and Pure Steam
Ultra High Pressure Steam
>  Portable / Mobile Package Solutions



Steam generators are industrial water-tube steam boilers of the once-through princip and with small and medium-sized steam outputs.

 Steam Generator Boilers in Strong & Reliable Design

They are developed and designed especially for reliability even during "heavy duty" operations - with no compromise on quality even though it mean higher purchase price. The focus is dedicated to ensure the best long term investment with lowest operational costs during the longest lifetime.

The pressure parts are designed as standard up to 40 bar pressure although operation pressure might between 3 - 10 bar (gauge). Pressure of 190°C and design temperature of 350°C on request.

This industrial type steam generator is also known as the steam generator boiler. It operates as a forced circulation water tube boiler. Unlike the conventional fire-tube steam boiler (fire/smoke tube boiler), the water in the steam generator boiler contains a very small amount of water and steam (equal the volume inside the pressure vessel i.e. inside the tube).

As listed up in the left column, this gives quite a few advantages.

The steam generator boilers are delivered in the range from 100 to 3,000 kg/h steam at design pressure going from 3 barg and all the way up to 190 barg (for special applications). These complete units are easy to install and does not require any special foundation; they can be place directly on a concrete floor.

The advantages are numerous - just image what you gain with a start-up time down to few minutes !

Get here a fast overview how to Choose your Boiler Type - the classic fire-tube type or this compact water-tube type.



Steam Troll.JPG (23704 bytes)

Steam Generator - Vertical type



Steam generators often comes with very high efficiencies equal low fuel consumption and low CO2 emission.

But special request on extra high efficiencies and extra low CO2 emission can be offered as a part of our general customized solution features. It costs a little more, but the overall cost are normally lower - and the environmental issue should also been taken into account.

Additional efficiency can be obtained by using an economizer (optional extra).



The steam generators are prepared with combustion chambers for ensuring Low NOx when choosing an appropriate Low NOx burner. This design also offer high efficiencies. More green solution, often a request. The long term extra costs are very often modest due to the higher efficiency.

NOTE! Without a suitable combustion chamber design, no Low NOx burner can ensure  environmental values with regard to NOx emissions - the boiler design is essential to ensure Low NOx.




Steam generators can be delivered in horizontal execution (with low height), or in vertical execution (occupying limited floor space). They are delivered insulated with stainless steel cover sheets and complete with burner, armatures, instrumentation, safeties and a control panel - and with full documentation including necessary certificates.

All steam generators are carefully checked, controlled and function tested prior to dispatch from the workshop.


The steam generators heaters are made with coils made of seamless tubes, where the feed water is preheated and evaporated during the flow through these. The heat is transferred to the water/steam mixture as radiant heat in the combustion chamber, where the inner cylindrical tube coil and a flat tube coil forms the chamber wall and the bottom respectively. Consequently refractory concrete is avoided. The combustion gasses are hereafter cooled in the outer convection part, as the gasses pass the space between the two tube coils. The thermal design ensures a modest volume of steam relative to the size of the heater, and allows unlimited thermal expansion due to the high temperatures. All TT BOILERS steam generators and steam boilers are designed and equipped according to German TRD boiler regulations and Danish boiler regulations and corresponding EN-norms.

DT steam generators are made in carbon steel, but also different grades of stainless steel.

Stor_Coil_2_Cut.jpg (23562 bytes)

Making the Steam Generators


Beside the standard execution the steam generators can be delivered in e.g. following variations:


More info about
  the 'R&D Workshop'



As standard the heaters are provided by international recognized and only high quality burner brands - for natural gas, light fuel oil, heavy fuel oil and combinations (dual fuel). This include Low NOx burner designs. Demands for special burner designs can be fulfilled and adapted in the heater design.


There are indeed some major differences between a steam generator and a classic 3-pass fire-tube steam boiler.

Advantages and disadvantages are present depending on the actual circumstances.

Read more about different type of steam boilers and about making the right choice on selecting the Correct Type of Steam Boiler. AB&CO offer both types and have no preferences in advising in favour of either type.






Steam generators are also delivered for production of clean steam for food industry, pharmaceutical industry, electronically industry etc.



oil/gas-fired clean steam generator     Tube coil of a clean steam generator                                   steam generator with reboilers for pure steam


Sanitary steam (clean steam) for food applications are provided by a steam generator made in high grade stainless steel. The photo above shows a unit  for Rolls Royce in UK which should also have other special features such as steam of  190 barg / 350°C. See more details here about clean steam.


For pharmaceutical industry a special grade of high quality sterile steam is used -  so-called pure steam. The photo above shows steam generators with capacity of 300 kg/h and 600 kg/h - with reboiler, grinded and polished internally. See more details here about clean steam..


wpeA.gif (11196 bytes)

Steam Generator - Special Customised Unit

Horizontal type only



Oil · Gas
[kg/h · Nm³/h]












   DTM 125

125 87 8,5 · 9 1700 1300 800 700 800 Ø150 150 175

  *    Measurement including control panel , which can be placed anywhere or delivered separately.
  **  Measurement adjusted with respect to nozzles (inlet feed water, outlet steam) which are located at the front.




Oil · Gas
[kg/h · Nm³/h]















   DT 300/100 100 67 7 · 7 1,800 1,400 1,400 1,000 1,500 ø210 440 460
   DT 300/150 150 100 10 · 10 1,900 1,400 1,400 1,000 1,500 ø210 445 465
   DT 300/300 300 200 20 · 21 2,000 1,400 1,400 1,000 1,500 ø210 450 470
   DT 300/400 400 266 26 · 28 2,100 1,400 1,400 1,000 1,500 ø210 455 475
   DT 600/700 700 466 46 · 49 2,550 1,850 1,500 1,100 1,500 ø250 600 650
   DT 1000/800 800 533 52 · 56 2,900 2,400 1,600 1,200 1,800 ø350 1,285 1,385
   DT 1000/1000 1,000 666 65 · 70 3,100 2,400 1,600 1,200 1,800 ø350 1,300 1,400
   DT 1000/1200 1,200 800 78 · 84 3,300 2,400 1,600 1,200 1,800 ø350 1,325 1,425
   DT 1500 1,500 1,000 98 · 105 On request
   DT 2000 2,000 1,333 130 · 139
All below figures and data are estimations for guidance only. The exact capacity appears from the quotation. Exact sizes to be determined as part of order effectuation and adjustment of the customised design.

Since most AB&CO models are customised units, the above figures only represent some of the available sizes. Above models are all oil or gas-fired, while dimensions on electrical heated models can be provided on request.

For using above table you should choose the size above your required heat capacity, to get the dimensions and weight for the unit.

TABLE VALUES · Presumptions
The below stated values for heat capacity and fuel consumptions are based on 80°C feed water temperature, 7 bar steam pressure, 90% efficiency and normal European quality light fuel oil (LCV=42 MJ/kg) and natural gas (LCV=40 MJ/Nm³)



An option is the container solution, comprising all equipment for ensuring a efficient steam production.

Containerized solutions are used widely as an fast and economical way to establish steam up to 2400 kg/h.

It can be used as an emergency steam back-up, when a steam supply fails and a fatal situation occurs. With a container solution you can rapidly be "on-steam" again.

This solution is used for end-user of steam, but it is certainly also as an attractive business opportunity to buy these for renting out - and thus offering the above services to end-users.

Steam generator boiler are also available in:

Read more about mobile solutions

Delivery options

10 / 20' containers :

Up to 1200 kg/h steam
operating pressures 1 - 190 bar

Up to 2400 kg/h steam
on two steam generator boilers
operating pressures 3 - 190 bar