Product Description

Cleaver-Brooks watertube boilers were industrial heating and steam-generation systems designed for large-scale commercial and industrial applications. Unlike firetube boilers, in which hot combustion gases pass through tubes surrounded by water, watertube boilers circulate water through a network of tubes exposed to heat from an external firebox or combustion chamber. This design allowed for higher operating pressures and greater steam output, making watertube configurations particularly well-suited to power generation facilities, manufacturing plants, chemical processing facilities, shipyards, hospitals, and other installations with substantial and continuous thermal energy demands.

Cleaver-Brooks, a Milwaukee-based manufacturer with a long history in the industrial boiler market, produced watertube boilers across decades of the twentieth century. The company became one of the more recognized names in commercial and industrial boiler manufacturing, and its equipment was installed in facilities throughout the United States and internationally. Because of the demanding operating environments in which these systems functioned — including extreme heat, high pressure, and continuous thermal cycling — robust insulation and heat-resistant materials were central to the engineering and construction of these units.

Asbestos Content

Litigation records document that Cleaver-Brooks watertube boilers incorporated asbestos-containing materials as part of their standard construction and insulation systems. Plaintiffs alleged that asbestos was used extensively throughout these units because of its well-established properties as a thermal insulator and fire-resistant material — properties that were considered essential for safe and efficient high-pressure steam generation.

Asbestos-containing components associated with these boilers, as identified in litigation records, include insulating cements and block insulation applied to boiler exteriors, internal refractory materials lining combustion chambers and fireboxes, gaskets used to seal pipe connections and access panels, insulating rope and packing materials used around doors, ports, and steam lines, and insulating blankets or sectional insulation covering boiler tubes and headers.

Plaintiffs alleged that the asbestos used in these applications was sourced from a variety of raw material suppliers and component manufacturers, meaning that the asbestos fiber content of any given installation could reflect contributions from multiple upstream product manufacturers. This multi-source exposure environment is consistent with patterns documented in industrial boiler litigation more broadly.

How Workers Were Exposed

Industrial workers who installed, operated, repaired, or decommissioned Cleaver-Brooks watertube boilers faced potential asbestos exposure through a range of occupational activities. Litigation records document that asbestos fiber release from these units could occur at multiple stages of a boiler’s service life, not only during initial installation.

Installation: Workers who received and installed new boiler systems were required to handle, cut, and fit insulating materials around tubes, headers, and combustion chambers. Cutting or shaping asbestos block insulation or insulating cement generated respirable dust that could be inhaled by installers and nearby tradespeople working in the same area.

Routine Operation and Inspection: High-pressure steam systems require periodic inspection and maintenance. Opening access panels, inspecting tube bundles, and testing gasket integrity brought workers into contact with aged asbestos materials. Vibration, thermal cycling, and pressure fluctuations common in industrial boiler operation caused asbestos-containing gaskets, rope packing, and insulating cements to degrade over time, potentially releasing fibers during normal operational activities.

Maintenance and Repair: Plaintiffs alleged that repair work on these units was particularly hazardous. Removing deteriorated insulation to access tubes, refractory, or internal components required workers to break apart or tear away asbestos-containing materials that had hardened or crumbled after years of heat exposure. This kind of work — described in occupational health literature as friable asbestos disturbance — is associated with elevated airborne fiber concentrations.

Overhauls and Refractory Work: Major overhauls involving the replacement of combustion chamber refractory linings, replacement of tube insulation, or rerouting of steam lines exposed workers to asbestos disturbance on a larger scale. Sandblasting, chipping, and grinding activities near asbestos-containing refractory or insulation surfaces were among the tasks plaintiffs alleged caused significant exposure.

Decommissioning and Demolition: Industrial workers involved in taking aging boiler systems out of service faced exposure risks as well. Dismantling older units required breaking down insulated components, removing gaskets and packing, and cutting through refractory — all activities that litigation records associate with fiber release.

Workers who were not directly handling asbestos-containing materials but who worked in proximity to those who were — a category sometimes referred to as bystander exposure — were also represented among plaintiffs in litigation against Cleaver-Brooks and related boiler manufacturers.

The trades most consistently identified in litigation records as potentially exposed through contact with industrial watertube boilers include industrial maintenance workers, boiler operators, pipefitters, millwrights, insulators, and facility engineers. However, litigation records document that exposure was not limited to any single job category; the nature of industrial boiler operation meant that multiple trades worked in close proximity to the same equipment.

Documented Product Identification

The following details are drawn from public asbestos litigation records, manufacturer catalog pages, technical manuals, and corporate history materials. Each item reflects the product as documented in those sources.

Documented asbestos-use period: 1931-Early 1980s

Corporate context: Cleaver Brooks merged with Aqua-Chem in 1967 and became a division of Aqua-Chem, Inc. Service operations were based at 11950 W. Lake Park Drive, Milwaukee, WI 53224.

Brand identification: All boilers prominently bore the name ‘Cleaver Brooks’

Industries served: commercial.

Documented product lines:

  • Cleaver Brooks Boilers (1931-Early 1980s). Commercial boilers prominently bearing the Cleaver Brooks name

Cleaver Brooks boilers were used in commercial applications from 1931 through the early 1980s; the company operated as a division of Aqua-Chem, Inc. following their 1967 merger.