1. Watertube Boilers

2. Water Tube Boilers
A water tube boiler is the opposite of a fire tube boiler.
Water flows through the tubes and that are incased in a furnace in which the burner fires into.
The tubes are connected to a steam drum and a mud drum.
The water is heated and the steam is produced in the upper drum.

3. Water Tube Boilers
Large steam users are better suited for the water tube boiler.
The industrial water tube boilers are typically used for producing steam or hot water for large industrial process applications.
Water tube boilers are usually not used for heating applications.

4. Water Tube Boilers
Reasons for changing from Fire Tube Boilers to Water Tube Boilers
Larger Capacities up to several million lbs/hr.
Higher Pressure and Temperature Steam up to 5,000 PSIG.
More Compact
Faster Responding to Load Changes

5. Water Tube Advantages
Less weight and space for the amount of steam generated
Flexibility when raising steam and answering sudden changes in steam demand
More adaptable for higher pressures and temperatures than the fire tube boiler
Better heat transfer characteristics resulting in higher boiler efficiency
Less danger of injury to personnel from an explosion

6. Water Tube Boiler Disadvantages
The requirements for the use of pure water
The need for constant skilled supervision during operation
Higher initial cost
Higher maintenance and repair costs on bent tube designs

7. Types of Water Tube Classifications
Number of Steam and Water drums
Drum arrangement
Arrangement of tubes
Types of headers
Water Circulation
Number of gas passes
Superheater location
Superheater heat transfer method

8. Number of Steam and Water Drums
Single Drum (Header Boiler) or Auxiliary Boilers
Two Drum “D” Type Boiler
Three Drum “A” Type or “M” Type Boilers

9. Header Type Boiler Safety Valve Steam Drum Exhaust Furnace Rear Header
Forward Header
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10. A-Type Water Tube Boiler
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11. A-Type Water Tube Boiler
Header
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12. M-Type Water Tube Boiler
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13. D Type Water Tube Boiler
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14. D-Type Water Tube Boiler
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15. D-Type Water Tube Boiler
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16. D-Type Water Tube Boiler
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17. D-Type Water Tube Boiler
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18. Drum Arrangement
Cross Drum if the drum is at right angles to the tube bank
Longitudinal Drum if the drum runs in the same line as the tubes that make up the tube bank

19. Types of Headers Box type headers Sinuous type headers
Circular type headers

20. Water Tube Boiler Headers

21. Water Tube Boiler Headers

22. Arrangement of Tubes Straight tube boilers
Bent tube boilers with tubes inclined or vertical

23. Water Tube Boilers
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24. Water Circulation Natural Circulation Accelerated Circulation
Forced Circulation

25. Number of Gas Passes Single Double Triple
Depending on the number of times the combustion gases pass through the generating tube banks

26. Superheater Location Pertaining to the positioning of the superheater
Overdeck
Interdeck
Underdeck

27. Superheater Heat Transfer Method
Convection Type
Radiation Type
Radiation-Convection Type

28. Auxiliary Boilers
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29. Auxiliary Boilers
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30. Auxiliary Boilers
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31. Auxiliary Boilers
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32. Auxiliary Boilers
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