Watertube Boilers

There are a few different types of watertube boilers, from a single pass vertical to coil tube to bent watertube designs. In the packaged commercial and light industrial market, watertube boilers typically have a smaller footprint and have less water content than a firetube boiler. Some watertube designs also offer higher efficiency than a firetube boiler as well. The packaged watertube boilers have design pressures from 15 psig to 300 psig and capacities up 1650 BoHP to in a single boiler. Water treatment is a key component for any boiler, but especially for watertube boilers. While the required treatment for a watertube boiler does not differ much from a firetube boiler, it is more critical to continue proper treatment. Both types of boilers will lose efficiency if not properly treated, but a watertube boiler is more susceptible to damage or failure from neglect.

In the large industrial and utility market, watertube boilers are the preferred design as they offer higher design pressures up to 2,000 psig, temperatures up to 1000°F, and capacities up to 500,000 lbs/hr. Due to their large design and pressure capabilities, these boilers typically require a more engineered approach and careful consideration is needed for key design points, such as low volumetric and furnace heat release rates, full membrane surfaces (including front and rear walls), and pressure vessel warranties.

In certain areas of the country, there are state-specific laws on the design of boilers. One such case has been in Ohio where there are restrictions on the amount of heating surface to run a boiler without an operator. However, the laws in Ohio have recently changed to allow boilers that exceed the heating surface requirement to be run without an operator by providing some additional monitoring and documentation.

Lathrop Trotter partners with Harsco Industrial – Patterson-Kelley, Miura and Unilux/Evolve to offer our customers the best watertube boiler solutions engineered for optimal efficiency, excellent performance, and the utmost reliability.

Harsco Industrial – Patterson Kelley

Harsco Industrial Patterson-Kelley offers a full line of condensing and non-condensing watertube hot water boilers. Their compact design allows for a large amount of MBH in a small footprint – designed to fit through standard doors which is ideal for retrofit applications.

• MODUFIRE – Natural gas or propane-fired, non-condensing copper finned water tube boilers with modulating control.  Input sizes ranging 750 – 3000 MBH rated to up to 160 psig.
• MACH – Natural gas or propane-fired, condensing aluminum water tube boilers with modulating control.  Input sizes ranging 300 – 4000 MBH rated to up to 125 psig.
• SONIC – Natural gas or propane-fired, condensing stainless steel water tube boilers with modulating control.  Input sizes ranging 300 – 4000 MBH rated to up to 160 psig.
• THERMIFIC VELOX –  Natural gas or propane-fired, non-condensing copper finned water tube boilers with on/off control.  Input sizes ranging 750 – 2000 MBH rated to up to 160 psig.

Miura Watertube Boilers

Miura boilers are a single pass, vertical design that can quickly deliver full steam output from a cold start-up in under 5 minutes, without creating a thermal shock to the watertube or to the enclosure. They are dual-fuel capable and are available with NOx reduction technology to sub 9 ppm. Its modular design offers 85% efficiency and a small footprint, providing a plant with a great amount of future flexibility.

• EX and EXH – Dual-fuel fired boilers with module sizes ranging from 50 to 300 BoHP, and design pressure from 70 psig to 300 psig.
• LX, LHL, and LXH –  Natural gas or propane-fired boilers with module sizes ranging from 50 to 300 BoHP, and design pressure from 15 psig to 300 psig.

Unilux/Evolve Watertube Boilers

Unilux offers a five-pass, bent watertube boiler for both steam and hot water with a tangent tube design, allowing for excellent convective internal pumping and heat transfer. The standard pressure on this design is 160 PSI / ASME Section IV, with higher pressures available. The Unilux series of watertube boilers offer the widest size range in this design. The controls are designed for easy access and maximum accuracy.

• Evolve – Natural gas, oil or propane steam, hot water, and high-temperature hot water boilers with sizes ranging from 800 to 1650 BoHP, rated up to 800 psig.
• LS Series – Natural gas, oil or propane-fired, low-pressure steam boilers with sizes ranging from 30 to 925 BoHP, rated up to 15 psig.
• HS Series – Natural gas, oil or propane-fired, high-pressure steam boilers with sizes ranging from 30 to 950 BoHP, rated up to 150 psig.
• W Series – Natural gas, oil or propane-fired, non-condensing hot water boilers with input sizes ranging from 1250 -38000 MBH, rated up to 160 psig.