ASH parts & services

Allen-Sherman-Hoff® Ash Handling

ASH parts & services

Allen-Sherman-Hoff® Ash Handling

B&W Environmental

About B&W’s Allen-Sherman-Hoff® (A-S-H®) Products

B&W is the original equipment manufacturer of all Allen-Sherman-Hoff® (or A-S-H®) ash handling equipment, systems and replacement parts.
Combining our strengths, history and experience, B&W’s extensive knowledge of the physical and chemical properties of various material combinations has made us an integral supplier of customized solutions.
Each project begins with careful analysis and planning to meet scheduling, execution and performance goals. We also provide dependable after-sales support, with spare or replacement parts, maintenance services, and component and system upgrades to maximize the life of your material handling equipment.


Allen-Sherman-Hoff® Ash Handling Parts and Service 
Phone: +1 740 687 4160 or toll free within  
North America 1 800 848 5086 
After-hours Emergencies 1 800 876 9762

Bottom Ash Solutions

B&W ASH Hydrobin dewatering bin

Hydrobin® Dewatering Bin

Proven, reliable approach for dewatering bottom ash

  • Gravity-driven water/solids separation
  • Low initial cost, shortest lead time
  • No outage required for installation
  • Utilizes existing hydraulic transport system (no modifications to boiler)
  • Located remote from boiler, small footprint
  • Ideal for batch transport of bottom ash
  • Up to 72-hour storage capacity

Submerged Chain Conveyor

Submerged Chain Conveyor  

Efficiently removes bottom ash from boilers burning solid fuels such as coal, bark, wood or refuse. 

  • Eliminates storage ponds
  • Removes material using less power
  • Uses less water to operate
  • Automatic ash dewatering
  • Less maintenance with fewer components
  • Easy access for inspection or maintenance

Submerged Grind Conveyor

Submerged Grind Conveyor (SGC) System

Offers maximized results and minimized modifications to the existing footprint. 

  • Meets zero-discharge bottom ash removal requirements
  • Simplified and cost-effective system
  • Offers flexibility in design to avoid disruption to operations and shorten installation time and costs
  • Reduces conversion costs by retaining existing ash hoppers and boiler seal plates

B&W Remote Submerged Chain Conveyor

Remote Submerged Chain Conveyor

  • Eliminates storage ponds
  • Simple design for ease of maintenance
  • Flexible design allows multiple ash disposal options
  • Up to twice the storage time of a submerged chain conveyor system installed under the boiler
  • Located remote from the boiler
  • Easy retrofit to plant having an existing bottom ash slurry transport system

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B&W provides new build, parts and services.

Fly Ash Solutions

B&W Pugmill Recycler

Pugmill Recycler

  • Provides an economical way to recycle FGD water in the fly ash which is sent to the landfill for disposal
  • Minimizes fugitive dust during operation by using flexible isolation curtains
  • Optimal mix to avoid unabsorbed water in transport vehicle
  • Overlapping paddle configuration minimizes ash buildup
  • Nozzles specifically target mixing area with fine mist of water
  • Easy access for routine maintenance
  • Water meter and valve for precise water flow control

B&W ASH Vacuum System

Vacuum System

  • Uses air as transport media below atmospheric pressure to entrain and convey material
  • Vacuum source is located at the discharge end of the conveying system
  • Ideal for shorter transport distances (< 1500 ft)
  • Safest design for indoor and hazardous environments
  • Uses fewer components
  • Less clearance required under hoppers
  • Low initial system cost

B&W Vacuum/Pressure Combination System

Vacuum/Pressure Combination System

  • Used for long conveying distances where vacuum system benefits are desirable in confined or hazardous locations, then transfer to pressure system for long distance
  • Initial material discharge from hoppers is by a vacuum system
  • Requires an intermediate collection vessel/transfer station
  • Pressurized conveyance system to storage silo

B&W ASH Pressure System

Pressure System

  • Can convey over longer distances (1000 to 10,000 ft
  • Simpler ash/air separation equipment at the storage silo
  • Airlock is required to transfer material from collecting hoppers to high pressure conveying line
  • Lower cost silos and related equipment
  • Lower operating costs
  • Eductor-based pneumatic system available for special applications

B&W ASH Dense-Phase Transport System

Dense-Phase Transport System

  • Variation of pressurized system but operates at higher ash-to-air ratios
  • Smaller transport line sizes, for intermediate material transport rates, will often be the lowest initial and operating cost system
  • Long distance conveyance, same capabilities as pressure transport systems

Site Services for Ash Handling Equipment

Through a dedicated team of professionals, B&W provides quality onsite services focused on the proper operation and maintenance of your ash handling equipment and systems. Our complete turnkey services encompass all onsite installation, project management and technical oversight, including: necessary labor, equipment, tools and consumables.


Allen-Sherman-Hoff®  Bottom and Fly Ash Systems

  • RSC2™ remote submerged chain conveyor

  • Hydrobin® dewatering systems

  • Dry bottom ash conveyors

  • Vacuum, pressure and combination fly ash systems

  • DenseASH dense phase pressure system

  • Conventional fly ash and scrubber byproduct handling systems

Fuel Feeder Systems

  • Feed hoppers

  • Hydraulic dampers

  • Changeable wear plates on feed pushers

B&W's Diamond Power & Allen-Sherman-Hoff Brands

Boiler Cleaning and Ash Handling Business to Better Serve our Customers

The company and brand you recognize as "Diamond Power" entered the boiler cleaning business in 1903 and has operated as a Babcock & Wilcox company since 1922.  Today, B&W Diamond Power® boiler cleaning systems, while much more elaborate and sophisticated than they were a century ago, still serve the same purpose: to keep boilers operating at peak efficiency.

The reliability and efficiency of your operations is important to B&W. 

Trust that B&W will continue to offer the innovative and proven Diamond Power® technologies and support for products including boiler cleaning technologies such as IK™ retractable, HydroJet ® and other boiler cleaning systems / sootblowers.

B&W's Allen-Sherman-Hoff® provides ash and material handling solutions. As part of our complete environmental technologies line, we continue to provide a variety of ash and material handling solutions, from completely dry bottom ash handling to fly ash and petroleum coke processing. These technologies offer environmentally sound solutions to address wet FGD (scrubber) wastewater and mitigate ash storage ponds.     

History of Allen-Sherman-Hoff (A-S-H)



Three mechanical engineers, Frank Berry Allen, John Baker and Frank H. Dunbar form the Baker-Dunbar-Allen Company in Cleveland, Ohio. Their goal was to improve coal handling techniques for power plants. In 1921, Frank Allen left for Philadelphia, Pennsylvania, to form a new company with Max Sherman and Leigh Hoff. Together they formed the Allen-Sherman-Hoff Company (A-S-H) and subsequently purchased the equipment drawings and patterns from the Baker-Dunbar-Allen Company.

1920 - 1929

1920 - 1929

Allen-Sherman-Hoff’s business initially consisted of the supply of cast iron hoppers for coal storage and the collection and conveyance of bottom ash below the boilers.

Allen-Sherman-Hoff Material Handling History

1930 - 1949

1930 - 1949

The original arrangement was modified in the early 1930s when A-S-H develops the HYDROSEAL pump, designed to better handle the high abrasive wear of the ash. Its use allowed the collected ash to be carried through pipes at faster conveying rates and farther distance from the boiler.

A-S-H introduces the Hydrovac™ pneumatic vacuum conveying systems for the transport of fly ash to the sluices. A new line of fly ash components is developed to combat the wear of abrasive fly ash moving at high velocities. HYDROVACTOR® vacuum producers and steam jet exhausters provided the required vacuum-induced flows. The hydraulic bottom ash handling system, utilizing the HYDROSEAL pump, dominated the ash handling industry until the introduction of the jet pump which provided improved performance at a lower cost with reduced maintenance.

1950 - 1959

1950 - 1959

A-S-H introduces its complete line of HYDRO-EJECTOR jet pumps in 1952.

1960 - 1969

1960 - 1969

The Allen Family retained control of the company until 1963 when the assets of the ash handling group were purchased by the Baldwin-Lima-Hamilton Company and a new corporation named Allen-Sherman-Hoff, Inc. was formed. This new company operated first as a subsidiary, then as a division, of Ecolaire Incorporated.

Pugmill 3600

1970 - 1979

1970 - 1979

Ecolaire establishes the offices of A-S-H in Malvern, Pennsylvania.

A-S-H successfully negotiates the technology transfer contract with the People’s Republic of China, establishing A-S-H’s dominance of the ash handling industry in the PRC. A-S-H was also awarded the two largest ash handling system contracts ever tendered at that time, both for Taiwan Power Company’s Taichung Station.

Allen-Sherman-Hoff advances its technology development in dilute-phase transport systems, pressure dense-phase transport systems and mechanical drag conveyors.



Allen-Sherman-Hoff acquires HydroAsh from the L. B. Foster Company of Pittsburgh, Pennsylvania. At the time of this acquisition, HydroAsh had established itself as the third largest ash handling equipment supplier in the United States. Under Allen-Sherman-Hoff, the HydroAsh group targeted the industrial ash handling market, its strongest niche. Eventually the design strengths and products of HydroAsh were assimilated within A-S-H’s product offerings.

In late 1987, Ecolaire merges with Joy Manufacturing Company. A-S-H’s operations were combined with Western Precipitation (WP), another Joy unit, forming Joy Environmental Technologies, Inc. The product offerings of this new company included A-S-H’s ash handling equipment and WP’s air pollution control equipment.



Anticipating a synergy with its highly successful sootblower and auxiliary boiler equipment business, Diamond Power Specialty Company (DPSC), part of The Babcock & Wilcox Company (B&W), acquires the assets of Joy Environmental.

Allen-Sherman-Hoff was established as a division of DPSC for the supply of traditional ash handling systems, equipment and parts, while the Western Precipitation air pollution control equipment was joined under B&W’s environmental technologies group.



Diamond Power International, Inc. (DPII) acquires certain assets of the Beaumont Birch Co., establishing Allen-Sherman-Hoff as part of DPII’s ash handling division.



As part of a company-wide strategy to integrate operations and emphasize its complete and broad power plant capabilities, B&W realigns the Allen-Sherman-Hoff operations under the B&W company brand, marketing all ash handling, systems, products, parts and upgrades with the Allen-Sherman-Hoff® (A-S-H®) product brand.
ASH system

New Build

Babcock & Wilcox (B&W) projects, new build
We consistently demonstrate the ability to successfully execute innovative solutions for our customers, from new equipment to large, complex full-scope engineering and construction projects.

Upgrades / Retrofits

Upgrades and Retrofits by B&W
Modifying, improving and maintaining existing equipment are vital considerations for the long-term viability and profitability of all operations.

Parts / Services

Babcock & Wilcox Parts and Service Support
An extensive network of worldwide regional service centers, field service engineers and technical support personnel are available to provide the customized service and aftermarket solutions for your requirements.