Feedwater Heaters — Asbestos Exposure Crosswalk
What This Equipment Is
Feedwater heaters are large shell-and-tube heat exchangers that progressively raise the temperature of boiler feedwater before it returns to the boiler. They use extraction steam drawn from intermediate stages of the steam turbine, recovering heat that would otherwise be lost in the condenser. A typical utility power plant has six to eight feedwater heaters arranged in series — low-pressure heaters between condenser and de-aerator, then high-pressure heaters after the boiler feed pump.
Feedwater heaters are pressurized vessels running at elevated temperature. The shell is insulated (block insulation), the extraction-steam piping is insulated (pipe covering), and every flanged connection — shell head, tube-bundle access, drain, vent, and instrumentation — historically used asbestos sheet or spiral-wound gaskets.
Asbestos Products Historically Used Around Feedwater Heaters
| Product Category | Where on the Heater | Notes |
|---|---|---|
| Block insulation | Shell exterior | Calcium silicate, magnesia |
| Pipe covering | Extraction steam, drain lines, feedwater piping | Magnesia, calcium silicate |
| Gaskets | Tube-bundle heads, channel covers, flanges | Sheet asbestos, spiral-wound asbestos-filled |
| Valve packing | Drain and vent valves | Braided asbestos rope |
| Insulating cement | Joints, fittings, irregular surfaces | Mixed dry, hand-applied |
| Removable insulation blankets | Channel covers and frequent-access areas | Sewn asbestos cloth + asbestos batting |
Why Feedwater Heater Work Was a High-Exposure Activity
Tube failures in feedwater heaters require pulling the tube bundle, plugging or replacing failed tubes, and reassembling — see Heat Exchangers for the recurring exposure sequence. Outage rebuilds typically address several heaters simultaneously, concentrating the work for the boilermaker, pipefitter, and insulator crews assigned.
Manufacturers Named in Litigation Involving These Products
- Johns-Manville — pipe covering, block insulation, gaskets
- Owens-Corning / Fibreboard — pipe covering, block insulation
- Armstrong World Industries — calcium silicate insulation
- Garlock Sealing Technologies — gaskets
- Crane Co. — valves and ancillary equipment
- Foster Wheeler — feedwater heater OEM named in installation/maintenance claims
- Combustion Engineering — feedwater heater OEM
Documented Product References
Images sourced from publicly available product-identification reference materials. Inclusion does not constitute a finding of liability against any company.
Trust Funds That May Apply
- Manville Personal Injury Settlement Trust
- Owens-Corning / Fibreboard Asbestos PI Trust
- Combustion Engineering 524(g) Asbestos PI Trust
- Garlock Sealing Technologies LLC Asbestos PI Trust
Trades Most Exposed at Feedwater Heater Work
Pipefitters, insulators (Heat & Frost), boilermakers, maintenance mechanics, plant operators handling routine valve work.
Jobsites in the Network
- Every Missouri power plant in the network
- See companion pages: Boilers, Heat Exchangers, Steam Turbines
Compiled from publicly filed asbestos litigation, EPA / state-DNR records, and industry-publication histories. Product and company references reflect what has been alleged or documented in publicly filed litigation. This page does not constitute a finding of liability against any company. Not legal advice; consult a licensed attorney about your specific situation.