Garlock Style 900 / 8500 Gaskets

Product Description

Garlock Style 900 and Style 8500 are compressed sheet gaskets manufactured by Garlock Sealing Technologies, a division of Coltec Industries. Production of these gaskets spanned from the 1920s through 1985, covering a period during which asbestos-reinforced sheet gasket materials were considered the industry standard for high-temperature, high-pressure sealing applications.

These gaskets were engineered for use in flanged pipe connections, pressure vessels, heat exchangers, pumps, and valve bonnets across the most demanding industrial environments in the United States. Their mechanical properties made them especially attractive to petrochemical facilities, oil refineries, power generating stations, and chemical processing plants where steam, corrosive acids, and elevated operating pressures required reliable flange seals.

Style 900 and Style 8500 were produced in sheet form and could be cut to specific dimensions by tradespeople in the field, allowing a single sheet to supply gaskets for numerous different flange configurations. This cut-to-fit versatility was a key selling feature and also a primary route through which workers received heavy asbestos exposures, as discussed below. Both styles were widely distributed through industrial supply chains throughout the mid-twentieth century and remained in commercial circulation until Garlock phased out asbestos-containing gasket production in 1985, consistent with evolving regulatory requirements under the Environmental Protection Agency’s Asbestos Hazard Emergency Response Act (AHERA) and OSHA’s asbestos standards.

Asbestos Content

Style 900 and Style 8500 gaskets were manufactured using chrysotile asbestos fibers embedded within a rubber or neoprene binder matrix. Chrysotile, also known as white asbestos, was selected for its flexibility, tensile strength, and resistance to heat and chemical degradation — properties that allowed it to maintain a reliable seal under the mechanical stress of bolted flanges and fluctuating operating temperatures.

In compressed sheet gasket manufacturing, chrysotile fibers were combined with the rubber or neoprene binder, then pressed under high pressure into rigid sheets. The resulting product contained asbestos fiber content that varied by formulation but was sufficient to pose a documented inhalation hazard during handling, cutting, and removal operations.

Garlock’s internal records, regulatory filings, and litigation documents have confirmed that both the Style 900 and Style 8500 product lines contained asbestos throughout their production history until 1985. These products are listed among the asbestos-containing materials for which the Garlock Settlement Trust was established to compensate injured workers.

How Workers Were Exposed

Exposure to chrysotile asbestos fibers from Garlock Style 900 and Style 8500 gaskets occurred in multiple occupational settings and through several distinct work activities. The following trades are documented as having faced meaningful exposure:

Pipefitters worked directly with these sheet gaskets on a routine basis. Cutting gaskets to size from bulk sheets — using knives, scissors, or die-cutting tools — released asbestos fibers into the breathing zone of the worker performing the cut and those nearby. Installing and removing gaskets from flanged connections also disturbed asbestos-containing material, particularly when workers scraped old, compressed gaskets from flange faces using wire brushes, scrapers, or grinding tools.

Refinery maintenance workers encountered Style 900 and Style 8500 gaskets throughout process piping systems, heat exchangers, and pressure vessels in petroleum refining operations. Maintenance shutdowns — known as turnarounds — required the removal of hundreds or thousands of gaskets across a facility, creating sustained, high-frequency exposure events. Workers in these environments often labored in confined spaces where airborne fiber concentrations had no means of dispersal.

Chemical plant workers faced comparable exposure conditions. The chemical resistance properties of neoprene-matrix chrysotile gaskets made them common in acid lines, solvent systems, and process piping throughout chemical manufacturing. Routine maintenance and emergency repair work in these environments brought workers into repeated contact with gasket materials.

Power plant mechanics installed and removed these gaskets from steam lines, turbine flanges, and boiler connections. Steam systems in power generation operate at high pressures and temperatures, conditions under which gaskets degrade and require periodic replacement. Each replacement cycle involved removing old, deteriorated gasket material — a task that generated asbestos dust — and cutting and fitting new sheet gasket material.

Across all of these trades, secondary exposures were common. Bystander workers, supervisors, and laborers present during cutting and removal operations were exposed without directly handling the gasket material themselves. OSHA’s asbestos standards, codified at 29 CFR 1910.1001 and 29 CFR 1926.1101, recognize that asbestos gasket removal and cutting operations are capable of generating airborne fiber concentrations above permissible exposure limits without adequate engineering controls and respiratory protection — measures that were rarely in place during the decades when Style 900 and Style 8500 were in widespread industrial use.

Documented Product Identification

The following details are drawn from public asbestos litigation records, manufacturer catalog pages, technical manuals, and corporate history materials. Each item reflects the product as documented in those sources.

Documented asbestos-use period: 1968

Corporate context: Garlock Inc. was a manufacturer of packing and gasket materials. The 1968 comparison chart indicates Garlock was an established industrial sealing products company producing equivalents to competitors including Johns-Manville, Raybestos-Manhattan, and John Crane.

Brand identification: LATTICE BRAID, CHEVRON, GARFITE product line names

Documented asbestos components: packing, gaskets, valve stem packing, compressed sheet.

Industries served: industrial manufacturing, chemical processing, petroleum refining, power generation, marine, food processing.

Naval / marine service: This manufacturer’s equipment is documented in connection with U.S. Navy and commercial-marine service.

Documented product lines:

  • LATTICE BRAID Asbestos Packing (1968). Braided asbestos packing available in multiple formulations including soft lubrication, controlled lubrication, heavy lubrication, gasoline resistant, and acid resistant versions. — asbestos components: packing.
  • High Pressure Asbestos Packing (1968). Asbestos packing with rubber back or rubber core for high pressure applications, available in ring, coil, and spiral configurations. — asbestos components: packing.
  • Square Plaited Asbestos Packing (1968). Square plaited asbestos packing including wire inserted versions, moly lubricated versions, and blue asbestos variants. — asbestos components: packing.
  • Braided Asbestos Packing (1968). Braided asbestos packing for hot oil service and general applications in square configurations. — asbestos components: packing.
  • Round Braid Asbestos Packing (1968). Round braid asbestos packing for valve stem applications and general service. — asbestos components: packing.
  • Twisted Asbestos Valve Stem Packing (1968). Twisted asbestos packing specifically designed for valve stem applications. — asbestos components: packing.
  • Compressed Asbestos Sheet Gasket Material (1968). Compressed asbestos gasket materials available in SBR, Neoprene, and Buna N binder formulations, including Navy Grade specifications. — asbestos components: gaskets.
  • Compressed Blue Asbestos (1968). Compressed blue asbestos gasket material for specialized sealing applications. — asbestos components: gaskets.

Garlock manufactured extensive lines of asbestos-containing packing and gasket materials with documented Navy Grade specifications. The 1968 comparison chart cross-references Garlock style numbers to competitor products from Johns-Manville, Raybestos-Manhattan, John Crane, Chesterton, and others.