The Aquatube boiler series is a flexible tube water tube boiler series with a wide range of capacities and applications .Compare to a firetube boiler; it takes less room to install and requires less area around the boiler for maintenance. It costs less to manufacture. The tubes and drums are so arranged that they are thermal shock proof and offer a very good heat transfer rate .The tubes are symmetrical on both sides of the furnace and only three tube configurations are required. The natural circulation is perfectly balanced, as well as the heat transfer rate. The tubes can be attached to headers by expanding, welding or ferrules. The arrangement of refractory being reduced to almost nothing, the maintenance is minimal .The Aquatube can be started up in minutes compared to hours for a firetube boiler. It can be fired with oil or gas or combination burners.
The Aquatube boiler can be used as a high temperature hot water heater as well as low or medium temperature hot water heater. The Aquatube can be used also for glycol/water mixture heating at low, medium or high temperature .It can also be used to heat medium or high temperature thermal fluids since it can be used as a forced circulation heater with an equally balanced and controlled fluid flow through each tube. See engineering bulletin #EB-101 &EB-102 for a more practical comparison.
Typical clients for such a boiler with be the commercial clients where hot water or steam is required for heating or for the processes like dry cleaners, apartment, building etc…, institutional clients like schools, university campus, hospitals, military based and industrial clients like food processing, textiles, chemicals, pulp & paper, wood processing etc…
The Aquatube boiler is ideal for boiler replacement projects. The entire unit can be supplied as a field assembly kit and is easy erected on site when boiler room access is a problem. It can also be shipped to the client as a complete assembly with burner and controls ready to be fired.
The design will allow a boiler manufacture, to mach any firetube boiler sizes and applications, to offer this design for high temperature hot water, for thermal fluid or glycol/water and to mach also the low end of the D-type, A-type and O-type range up to 40,000 lbs/hr (18 tons/hr) or 1200HP (12000kw).This design can also be built for very high pressures. It is the most versatile watertube boiler design on the market for capacities ranging from 20HP to 1200HP (200 to 12000kw).

The Aquatube Boiler Standard Equipment:

-High limit temperature control with manual reset.
-Modulating or high low controller.
-Probe type low water cut off.
-Boiler or burner mounted control panel.
-Optional combustion control system and boiler available to comply with the most stringent specifications and applications.
-Pressure gauge.
-Operating temperature controls.
-Safety relief valve(s).
-Flame safe guard control.
-Main and pilot fuel trains.
-fully modulating or high low burner.
-Convenient operator controls and status lights.

Efficiency:
-The Aquatube boiler is a multi pass balanced flow watertube design with staggered tubes and longitudinal gas passes. Heat transfer and turbulent gas flow is optimized for efficient heat transfer.
-Casing insulation characteristics are excellent. The tangent tube furnace walls are insulated with 2200Deg F ceramic fiberboard secured by the heavy gauge steel inner casing panels. The steel outer cladding allows for a suitable air gap for low outer casing temperatures and minimal radiation losses.
-Efficiencies of up to 85% are normal without the use of external heat recovery equipment.

Emissions:
-The generous furnace volume design and resultant low heat release rates with minimal use of refractory result in a boiler design that is excellent for low NOX applications.
-NOX emissions lower than most current regulations are easily achieved.

Symmetrical Design:
-True symmetrical and staggered tube layout with balanced combustion gas and fluid velocities.
-Symmetrical tube configuration allows for minimal tube removal clearances of less than half a boiler width between boilers in multiple unit installations.

Low Maintenance:
-Tube to header connections are industry standard, rolled and expanded or seal welded depending on the boiler capacity and application. Optional drive fit ferrules for ease of sit assembly are also available.
-All inner casing panels are welded to provide a gas-tight inner envelope and outer casing panels are of bolted construction for ease of assembly and easy removal for maintenance.
-The Aquatube boiler is thermal shock proof on the fluid side and combustion gas side. Water return temperatures on the boiler are acceptable at the minimum allowable temperature above the flue gas dew point .Differential temperatures of up to 150Deg F can be achieved when operating on high temperature water or thermal fluid.
-Large diameter down comers located inside the boiler casing provides excellent natural circulation. There is no requirement for external circulating pumps or site insulation.
-Access to the furnace is available through a rear door without changing the burner setting or disconnecting fuel piping.
-Optional soot blowers can be supplied for applications when heavy oil or high fouling factor fuels are fired.
-A Water-cooled rear target wall design is supplied to provide additional heating surface area, higher efficiency, lower emission results and the elimination of high-maintenance refractory .An optional water-cooled front wall design is available to provide additional heating surface and the complete elimination of refractory.

Retrofit:
-The Aquatube boiler is ideal for boiler replacement projects. The entire unit can be supplied as a field assembly kit and is easily erected on site when boiler room access is a problem. As the entire boiler assembly can be bolted and the tubes can utilize a drive fit there are no requirements for site welding or pressure vessel welding certificates.

Aquatube Boiler Designs Include:
-Low water content and forced circulation boiler designs for operator exempt applications
-Low and medium temperature hot water boilers.
-High temperature hot water boilers.
-High and low temperature water glycol heaters.
-High temperature hot thermal oil heaters.
-High pressure steam boilers.
-Low pressure steam boilers.