Steam Traps — Asbestos Exposure Crosswalk
What This Equipment Is
A steam trap is a small but ubiquitous valve at the low point of every steam line, drain leg, and heat exchanger. Its job is to discharge condensate (water) from the steam system while keeping live steam in. Every industrial facility with a steam plant has dozens, hundreds, or thousands of them. They sit on hot piping that is always insulated.
Steam traps are not made of asbestos. The exposure comes from the pipe covering that wraps them, the gaskets sealing their flanges, the packing on associated bypass valves, and the dust kicked up when traps are pulled for rebuild or replacement.
Asbestos Products Historically Used Around Steam Traps
| Product Category | Where on the Trap | Notes |
|---|---|---|
| Pipe covering | Steam supply and condensate return | Magnesia, calcium silicate — cut and removed during every trap change-out |
| Insulating cement | Field fitting at trap body and flanges | Mixed dry, hand-applied |
| Gaskets | Trap flange and union joints | Asbestos sheet gasket material |
| Packing | Bypass valve stems | Braided asbestos rope |
Why Trap Maintenance Was a High-Exposure Activity
Steam traps fail. They are rebuilt or replaced on a recurring cycle that, in a large plant, can mean hundreds of change-outs per year. Every change-out historically required: cutting and removing pipe covering, breaking the old flange gaskets, scraping joint compound off the trap body, installing new gaskets, and re-insulating the run. Each step disturbed asbestos.
For pipefitters and maintenance mechanics whose shop responsibility was steam-trap survey and repair, the cumulative exposure across a career could be substantial even if no single trap job involved much material.
Manufacturers Named in Litigation Involving These Products
- Johns-Manville — pipe covering
- Owens-Corning / Fibreboard — pipe covering
- Eagle-Picher — block insulation
- Armstrong World Industries — calcium silicate, magnesia cement
- Garlock Sealing Technologies — sheet gaskets
- A.W. Chesterton — packing materials
- Crane Co. — valves and ancillary equipment
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
- Eagle-Picher Industries PI Settlement Trust
- Armstrong World Industries Asbestos PI Settlement Trust
- Garlock Sealing Technologies LLC Asbestos PI Trust
Trades Most Exposed at Steam Traps
Pipefitters, maintenance mechanics, insulators (Heat & Frost), boilermakers during outages.
Jobsites in the Network Documenting Steam-Trap-Heavy Operations
- Anheuser-Busch Brewery, St. Louis, Missouri — large-scale brewery steam plant
- Most Missouri power plants and industrial facilities
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.