Steam Boiler Breakdown: Fire Tube vs. Water Tube

Depending on the industry, you may have to choose between a fire tube or a water tube boiler. These two steam boilers both have their benefits but will provide better results for particular industries. Our specialist boiler sales team will be breaking down these two popular boiler types so you can have a better understanding of them, and what will best suit your operations.

Fire tube boilers

Sometimes referred to as shell boilers or drum boilers, fire-tube boilers are thought of as the more cost-effective steam boiler solution and are suitable for smaller industrial applications. With fire tube boilers, the burner produces gases that travel through small tubes in a pressurised cylindrical drum, or shell, surrounded by water; this creates the steam. Fire tube boilers can sometimes be distinguished by passes — the metric used to measure how many times the flue gas (combustion gas) passes through the pressure vessel, transferring heat to the water to create steam.

Wet and dry back

Fire tube boilers can be either wet or dry back. Wet back boilers have water-cooled combustion chambers, which increases the heat exchange surface and eliminates the need for the rear outer casing to be protected from excessive heat. Dry back boilers rely on refractory lining to increase the heat exchange surface.

Pressure rating

The pressure rating and maximum output of a fire tube boiler tend to be limited by the furnace thickness. The code states that the maximum furnace thickness cannot exceed 22 mm. This is one of the reasons that fire tube boilers are ideal for smaller industrial applications as their maximum pressure rating and output typically will not meet the demands for higher intensity applications.

Compact and flexible

Fire tube boilers are fairly small in terms of physical footprint and thus are available to purchase in package form making them easy to transport and install on-site. Additionally, this also makes them easier to relocate should the need arise. Their general cleaning and maintenance are easy to handle with simple, regular cleaning schedules and readily available replacement parts. If you require any assistance with your fire tube steam boiler maintenance, then get in touch with our boiler sales team today.

Water-tube boilers

The easiest way to understand a water tube boiler is to think of it as the opposite of a fire tube boiler. In this instance, water flows through the tubes and the hot combustion gases pass around the tubes, heating up the water. Water-tube boilers generally have multiple drums (or shells) compared to the single drum in a fire tube boiler, this also means they can be overall larger in size (but are also available in smaller sizes). A standard water tube boiler consists of multiple burners positioned on the wall in either vertical or horizontal firing configurations.

High-pressure steam boiler

Water-tube boilers tend to have higher maximum pressure outputs compared to fire tube varieties with capabilities of reaching as high as 5,000 psig. To compensate for the equivalent amount of stress but higher pressure levels, the tubes are smaller in diameter. The higher pressures and faster recovery rates of water tube boilers compared to fire tube boilers are a couple of the reasons why they are preferred in higher-output applications such as chemical processing and power generation stations.

Models for every application

As mentioned earlier, water tube boilers can be both large and small in design. The smaller models are available in packaged steam boiler form, making them easier to transport and install by our boiler service team. The larger designs, however, must be transported in separate parts (these would be boilers suitable for high-output industries) and assembled at the site — resulting in a longer install time.

High performance, High efficiency

Water-tube boilers are made for high performance, so it’s no surprise that their efficiency is made to match the high-output industries they’re made for. They’re so efficient that they can even be used to produce superheated steam (perfect for high-output energy generation applications) and saturated steam (ideal for heating applications).

Are you looking for a quality steam boiler?

Tomlinson Energy Service is Australia’s premium steam boiler manufacturer and supplier. We can deliver unparalleled products and services tailored specifically for your industry so you always know you’re getting the perfect fit for your operations.

Get in touch with our boiler sales team today by calling your state office or filling out our online contact form.