Valve Rings

Asbestos in Valve Rings

The term "valve ring" may refer to a number of different products or devices used in a range of applications. These applications include plumbing, automotive or HVAC systems and even aerospace. At its most basic element, a valve ring is a type of gasket, used to provide a secure seal between two surfaces so as to prevent leakage. Sometimes these are prefabricated for specific applications; other times they must be cut to fit from a sheet of material.

Although the use of asbestos in these products was phased out in the 1980s, according to an investigative report in 2000, dust from auto repair shops still contained sizable amounts of asbestos fiber. This is principally due to the fact that brake pads and brake shoes manufactured overseas still use asbestos, and these products are designed to literally wear away under use. Most valve rings today are made from silicon or other substances, although again imported valve rings may have a high asbestos content.

Hazards Associated with Valve Ring Products

One of the hazards posed to mechanics, pipefitters and in the early years, aircraft and aerospace engineers, was asbestos. This danger was particularly acute when such workers had to cut valve rings and other gaskets from sheets of asbestos materials. During the cutting process, fibers would escape into the air where they could be easily inhaled by workers in the vicinity.

What happens once these fibers enter the respiratory system can vary depending on the type of asbestos. Chrysotile or "white" asbestos was most commonly used in industrial and engineering applications. While still quite harmful, the white asbestos did somewhat less damage to lung tissue; the fibers cause abrasions on the inner surfaces of the lungs, resulting in a build-up of scar tissue over time.

The other two common varieties of asbestos, "blue" and "brown," could cause chronic inflammation in cells and lead to the development of lung cancer or pleural mesothelioma.

Sources

Bowker, Michael. Fatal Deception: The Untold Story of Asbestos (New York: Touchstone, 2003)

Schneider, Andrew and Carol Smith. "Nation's Mechanics At Risk From Asbestos." Seattle Post-Intelligencer, 16 November 2000.