Product Description
A.W. Chesterton Company (Woburn, Massachusetts) marketed through the mid- to late twentieth century a line of rotating-shaft mechanical seals as an engineered alternative to conventional braided packing for pumps, mixers, and agitators. Chesterton mechanical seals were supplied both as cartridge assemblies (pre-assembled seal, sleeve, and gland plate ready for slip-on installation over the shaft) and as component-style seals (rotating and stationary faces, springs, and secondary sealing elements shipped as loose parts for field assembly).
Chesterton mechanical seals were installed in demanding rotating-shaft applications across refineries, chemical process plants, pulp and paper mills, power stations, and industrial mixer and agitator service, where the operating conditions — high temperatures, corrosive process fluids, or hazardous product containment — pushed conventional braided packing beyond its practical service limits.
Plaintiffs alleged in publicly filed U.S. asbestos personal-injury and wrongful-death litigation that A.W. Chesterton mechanical seals — through the asbestos era — used asbestos-fiber secondary sealing elements (backup gaskets, cup gaskets, wedge gaskets, and elastomer-alternative sealing rings behind the rotating seal face) in high-temperature and chemical service, asbestos static gland gaskets between the seal gland plate and the pump stuffing-box face, and asbestos-fiber gaskets on flush-line and quench-line connections.
Workers Exposed
Millwrights and industrial maintenance mechanics who installed and later replaced Chesterton mechanical seals allegedly disturbed asbestos-containing components during routine service. Mechanical-seal replacement is a labor-intensive task: the pump is decoupled, the gland plate is unbolted, the failed seal assembly is pulled from the stuffing box, and the mating faces are cleaned and re-gasketed for the new seal. Plaintiffs alleged that removing the spent seal generated fiber release from the deteriorated asbestos secondary elements, that scraping the gland-face gasket residue generated dust, and that cutting and installing new asbestos gland gaskets and flush-line gaskets exposed workers at close quarters. Refinery operators, chemical-plant mechanics, and paper-mill maintenance workers performed these tasks on scheduled and unscheduled maintenance across careers spanning decades. Pipefitters who broke and remade the flush-line, quench-line, and drain piping into the seal gland disturbed the asbestos gaskets on those connections.