Product Description
Trane manufactured steam- and hot-water-driven lithium bromide/water absorption chillers as a companion product line to its centrifugal chiller business. Absorption machines used a lithium bromide brine as the absorbent and water as the refrigerant; heat drove the refrigeration cycle rather than mechanical compression, so the machine ran on low-pressure steam or hot water from an existing boiler plant.
These machines were popular in hospitals, universities, government buildings, and industrial cogeneration sites where steam was already available. Each unit was a large, bolted-flange pressure vessel divided into an evaporator section, absorber section, generator section, and condenser section — every one of those sections joined by gasketed flanges, tube-sheet bolt patterns, and access covers.
Plaintiffs alleged in publicly filed U.S. asbestos litigation that Trane specified compressed asbestos sheet gaskets for the generator-section head, the condenser-section shell flange, the main body flange, the tube-bundle access covers, and the purge-unit connections on lithium bromide absorption chillers manufactured from the 1950s through the late 1970s. Compressed asbestos sheet was selected because lithium bromide brine is aggressive and the generator ran at temperatures that would degrade most non-asbestos gasket compounds of the era.
Workers Exposed
Absorption chillers required more frequent teardown than mechanical-compression chillers because the lithium bromide brine crystallized during operational upsets, the purge unit had to be pulled for maintenance, and the water-tube bundles fouled with corrosion product and had to be rodded or replaced. Every one of those maintenance events required breaking a gasketed joint.
Plaintiffs alleged that HVAC service technicians, refrigeration mechanics, operating engineers, boilermakers, and pipefitters routinely scraped and wire-brushed cooked-on asbestos gasket residue from the generator flange, the shell flange, and the tube-sheet during Trane absorption chiller service. The generator section ran hotter than most chiller flanges — steam supply temperatures at the generator commonly exceeded 240 degrees Fahrenheit — which fused the gasket to the flange face and made scrape-off unavoidable.
Litigation records document that this work was performed inside mechanical rooms without wet-methods dust control and without warning labels identifying the gasket material.