UBW Boilers

P. C. McKenzie Company is pleased to represent UBW Boilers, a division of Precision Boilers.

UBW manufactures a diverse line of high efficiency for heating or process applications. These flex-tube boilers are available in sizes ranging from 50 BHP to 2400 BHP in both Hot Water and Steam configurations. 

The UBW design is a two-drum system with multiple longitudinal gas passes separated by tangent water walls resulting in long turbulent gas travel without gas stratification.

General Information:

The furnace is entirely water cooled on all four sides and heat adsorption does not exceed 60,000 BTU per cubic foot of furnace volume. Large downcomers are located outside the heat transfer zone to ensure positive natural circulation without having to rely on external circulation pumps. A structural steel frame to ensure that undue stress is not placed upon the heat exchanger assembly independently supports the boiler drums.

The pressure vessel is warranted against thermal shock damage for twenty years at temperature differentials up to 150 degee F. 

UBW MODEL MC Hot Water Boilers - 9.5 BHP to 200 BHP - Features and Benefits

• Built in accordance with Section I or Section IV requirements
• Customer units are available to meet job specific requirements
• Left and right hand tube configurations allows for shared tube removal space
• Full access to the combustion chamber through one side of the vessel
• Equal heat absoption by all tubes in furnace and convection area
• Tube design provides constant air velocity from furnace to stack for higher efficiency
• Utilizes 1.5" .105 wall tubes on all sizes (9.5 HP - 200HP)
• Tangent water wall tube configuration eliminates gas flow directional baffles that could corrode and increase soot collection
• Furnace walls comprised of water-cooled tube on roof, floor and one side for maximum heat transfer
• 5 square feet of heating surface per boiler horsepower
• Conservative heat transfer rates (Btu/sq.ft.) provides longer tube life
• Minimizes NOx emission: less than 50 PPM (gas) with standard burners, less than 20
• PPM with low NOx and less than 10 PPM with ultra low NOx
• Design permits complete combustion with lower heat release rates (Btu/cu.ft.) than other designs
• Hand-hole plates for waterside inspection, eliminates hard to remove plugs as used with other designs
• Removable side [panels and casing for easy access to tubes
• 11 Gauge inner casing provides for firebox pressure of 3" W. C.
• Heavy gauge steel on inner and outer casing
• 2" fiberglass insulation between casings for near ambient exterior surface temperature
• Field erectable with no code welding
• Pressure Vessel Warranty of 20 Years Against Thermal Shock

UBW MODEL UF Boilers - Features and Benefits

• Built in accordance with Section I or Section IV requirements
• Independent Inspection for Code compliance ensures safety and reliability
• Custom units available to meet job specific requirements

Pressure Vessel Design

• Tube configuration ensures equalized water flow and gas flow at all load conditions
• Ensures equal heat absorption by all tubes in furnace and convection area

Multi Pass Gas Travel Design

• Tube design provides constant air velocity from furnace to stack for higher efficiency
• Tube configuration eliminates gas flow directional baffles that could corrode and increase soot collection.

Tangent Wall Furnace Design

• Furnace walls comprise of water-cooled tubes on both sides, roof, and floor for maximum heat transfer
• Conservative heat transfer rates (Btu/sq.ft.) provides longer tube life

Generous Furnace

• Minimizes Nox emissions: less than 50 PPM (gas) with standard burners, less than 20 PPM with low NOx and less than 10 PPM with ultra low NOx
• Permits complete combustion with lower heat release rates (Btu/cu.ft.) than other designs

Inspection/Maintenance

• Rear furnace access for full inspection of furnace: eliminates sidewall refractory burnout inherent with other designs
• Hand-hole plates for waterside inspection, eliminates hard to remove plugs as used with other designs
• Minimum aisle spaces for tube removal as no single tube transverses the width of the boiler
• Removable side panels and casing for easy access to tubes

Double Wall Casing Construction

• 11 gauge inner casing provides for firebox pressure of 3" W. C.
• Heavy gauge steel outer casing for durability
•  Insulation between casings for near ambient exterior surface temperature

Pressure Vessel Warranty of 20 Years Against Thermal Shock

• Confidence against thermal shock damage