Steam Turbines — Asbestos Exposure Crosswalk

What This Equipment Is

Steam turbines convert high-pressure, high-temperature steam into mechanical rotational energy, which drives an electrical generator (in power plants) or compressors, pumps, and other process equipment (in refineries, chemical plants, and shipboard propulsion). They are the heart of every coal-fired, oil-fired, gas-fired, and nuclear power station, and they were a fixture of large industrial steam plants from the early 20th century through the present.

The major turbine OEMs through the asbestos era — roughly 1920 through 1980 — were:

  • General Electric (GE) — the dominant U.S. manufacturer of large utility steam turbines, including the units installed at most of the power plants in the OBLF case docket
  • Westinghouse Electric Corporation — GE’s principal competitor; also supplied a substantial share of U.S. utility and industrial turbines
  • Allis-Chalmers — large industrial and smaller-utility turbines
  • DeLaval Steam Turbine Company — high-speed industrial and marine turbines
  • Terry Steam Turbine — auxiliary steam turbines, often for pumps and feedwater drives
  • Skinner Engine Company — smaller industrial turbines

For any specific power plant, the OEM of each unit is documented on the unit nameplate, in the EIA Form 860 generator registry, in FERC filings, and in utility-company annual reports. The standard practice for documented powerhouse jobsite pages is to name the OEM of the boilers, turbines, and generators present — this is an exception to the general route-through-Product-Crosswalk rule for product attribution.

Why Turbine Work Was a High-Exposure Activity

Steam turbines operate at temperatures from roughly 800°F to over 1000°F at the high-pressure inlet, dropping to lower temperatures through successive expansion stages. Through the asbestos era, every external surface of the turbine that operated above ambient temperature was wrapped with asbestos insulation to retain heat and protect personnel from contact burns.

The specific asbestos-containing components present in a typical steam turbine of that era included:

  • Casing insulation — thick layers of asbestos block insulation and asbestos cement applied directly to the turbine outer casing, then covered with sheet metal lagging
  • Expansion joints — woven asbestos cloth or asbestos-rubber composite at the bellows-style joints connecting steam piping to the turbine inlet
  • Gland packing — braided asbestos rope used to seal the rotating turbine shaft where it exits the casing, preventing high-pressure steam leakage
  • Pipe covering at the steam piping leading into and out of the turbine — same family of products (pre-formed sectional pipe covering, often Johns-Manville Thermobestos, Owens-Illinois Kaylo, or Pittsburgh Corning Unibestos)
  • Refractory cement at the turbine bearings and gland boxes — high-temperature asbestos-containing castable

Insulators and pipefitters who applied, repaired, and removed asbestos turbine insulation during construction, scheduled outages, and major overhauls reportedly experienced among the highest fiber concentrations of any work in the powerhouse. The cutting and tearing of asbestos block insulation during turbine outage work — when the casing insulation was removed to access internal components — released dense clouds of asbestos fibers in the immediate breathing zone of the workers performing the task. Allied trades working alongside (boilermakers, ironworkers, sheet metal mechanics, electricians) were also reportedly within exposure range.

Manufacturers of the turbines themselves are documented in publicly filed asbestos litigation as having specified, supplied, or otherwise required asbestos insulation on their equipment — even though the OEMs were not necessarily the manufacturers of the asbestos insulation itself. Boilers and turbines of this era are documented in public litigation records as having used asbestos-containing materials per the industry standard of the time.

Manufacturers Named in Litigation Involving Asbestos Turbine Insulation

The turbine OEMs commonly named in publicly filed asbestos product-liability litigation include:

  • General Electric Company — the largest body of turbine asbestos-related cases
  • Westinghouse Electric Corporation (now part of Viatron Industries / CBS Corporation through corporate restructuring; certain asbestos liabilities flowed to bankruptcy trusts)
  • Allis-Chalmers Corporation
  • DeLaval Turbine (now IMO Industries)
  • Terry Steam Turbine (now Dresser-Rand)
  • Skinner Engine Company

The insulation products specified for these turbines came from the standard set of asbestos pipe covering and block insulation manufacturers — see the Pipe Insulation and Block Insulation crosswalk pages.

Trust-Fund References

Workers exposed to asbestos turbine insulation typically file claims against:

  • The turbine OEM (if it has an active trust, as several do)
  • The asbestos insulation manufacturer whose product was on the specific unit (Johns-Manville Trust, Owens Corning Trust, Pittsburgh Corning Trust, etc.)
  • The insulation-contractor employer (if the contractor was named in litigation)

The unit nameplate and the contractor’s dispatch records typically establish the link between the worker and the specific equipment.

References to manufacturers, products, and facilities reflect what has been alleged or documented in publicly filed asbestos litigation and public regulatory records. This information does not constitute a finding of fact or liability. This site does not provide legal or medical advice. No attorney-client relationship is created by use of this site.