John Crane Mechanical Seals with Asbestos Components

Product Description

John Crane, Inc. is a global manufacturer of mechanical seals, seal support systems, and related industrial components. Founded in the early twentieth century and operating under various corporate names throughout its history, the company became one of the most widely recognized suppliers of mechanical sealing technology to refineries, chemical plants, power generation facilities, and heavy manufacturing operations across the United States and internationally.

Mechanical seals are precision-engineered devices installed in rotating equipment — most commonly pumps, compressors, mixers, and agitators — to prevent process fluids from leaking along the rotating shaft. Unlike traditional packing materials that rely on compression to create a seal, mechanical seals use a pair of flat, lapped sealing faces held together by spring force and hydraulic pressure. The stationary face is mounted in the equipment housing; the rotating face turns with the shaft. Together, the two faces form a barrier that contains fluids ranging from water and light hydrocarbons to caustic chemicals and high-temperature steam.

Throughout much of the twentieth century, John Crane manufactured mechanical seals that incorporated asbestos as a functional component. Asbestos was used in secondary sealing elements — including elastomeric or compressed-fiber packing rings, wedges, and other flexible components seated behind or around the primary seal faces. These secondary elements prevented leakage along the shaft bore and accommodated slight misalignments or thermal expansion in the equipment. Asbestos-containing secondary seals appeared in numerous John Crane product lines sold under a variety of part numbers and catalog designations.

John Crane seals were standard equipment in the petroleum refining, petrochemical, pulp and paper, marine, and power generation industries. Because rotating pumps and compressors are fundamental to nearly every continuous-process industrial operation, John Crane products achieved extremely wide distribution, appearing in virtually every large industrial facility in the country during the mid-to-late twentieth century.

Asbestos Content

Litigation records document that John Crane mechanical seals contained asbestos fiber in their secondary sealing components. Plaintiffs alleged that the asbestos-containing elements within these seals included compressed non-asbestos (CNA) fiber packing and woven or braided packing rings, as well as molded elastomeric components reinforced with asbestos fiber — all designed to withstand the elevated temperatures, pressures, and chemical exposures encountered in industrial process equipment.

Plaintiffs further alleged that John Crane was aware for decades that asbestos fibers were present in these sealing components and that disturbance of those components during installation, maintenance, and removal could release respirable asbestos dust. Court and deposition records introduced in litigation reference internal company documents related to product composition and the transition away from asbestos-containing materials in certain product lines during the 1980s and 1990s.

Because John Crane mechanical seals were sold to equipment manufacturers as original components and also distributed as replacement parts through industrial supply channels, asbestos-containing versions of these seals were in circulation and active service well after their initial manufacture date, extending potential exposure timelines for workers who performed maintenance on aging equipment.

How Workers Were Exposed

Industrial workers in a broad range of trades encountered asbestos-containing John Crane mechanical seals during the normal course of their work. Litigation records document that exposure occurred primarily during three types of activities: initial installation of new seals, routine preventive maintenance, and emergency repair or replacement of failed seals.

Installation. When new seals were fitted to pumps and other rotating equipment, workers handled the asbestos-containing secondary sealing components directly. Fitting the seal to the shaft required positioning and sometimes trimming or adjusting the secondary elements, activities that plaintiffs alleged could release asbestos fibers into the breathing zone of the installer.

Maintenance and inspection. Mechanical seals in process service have finite service lives and require periodic inspection. Workers who opened pump housings to inspect seal condition disturbed accumulated residue on and around the seal faces. Plaintiffs alleged that dried process fluid residue mixed with deteriorating asbestos fiber from secondary elements created friable material that was dislodged and aerosolized during these routine inspection tasks.

Seal removal and replacement. When a mechanical seal failed — indicated by visible leakage or elevated vibration — the pump had to be isolated, drained, and disassembled. Removing a worn or failed seal required extracting the secondary elements from their fitted positions in the shaft bore or housing. Litigation records document plaintiffs’ accounts of these components being scraped, pulled, or cut out, generating visible dust in poorly ventilated equipment rooms, pits, and confined spaces. Replacement seals were then fitted using the same handling procedures described above.

Workers most frequently identified in litigation as having been exposed include pump mechanics, millwrights, pipefitters, maintenance machinists, and general industrial maintenance workers employed at oil refineries, chemical plants, power stations, paper mills, and shipyards. Plaintiffs alleged that bystander workers — those in the vicinity of seal installation or removal activities but not performing the task directly — also sustained exposure through ambient fiber release.

The frequency of exposure is a significant factor raised in litigation. In facilities where large numbers of pumps were in service, seal maintenance was a recurring, high-volume task. Workers whose careers centered on pump maintenance could have performed hundreds or thousands of seal-related work cycles over decades of employment, potentially resulting in cumulative asbestos exposures that plaintiffs have connected to diagnoses of mesothelioma, asbestosis, and lung cancer.