• TECH TALK •
Hidden Leaks: The Role of Bellows Sealed
From refineries processing hazardous chemicals to pharmaceutical and thermal power plants, this valve design is a critical tool that effectively combats environmental pollutants.
• By Melanie Jackson and Dan Fisher, Dixon Valve & Coupling Company
Fugitive emissions are the unintentional release of gases or vapors from pressurized equipment due to faulty seals, connections, or other mechanical failures. They can escape from valves, pumps, flanges, and other components in chemical plants, refineries, and manufacturing facilities. Often unnoticed due to their diffused nature, these leaks significantly contribute to environmental pollution.
Unlike exhaust or deliberately vented emissions, fugitive emissions are difficult to quantify and monitor. Key chemicals include volatile organic compounds( VOCs), greenhouse gases( GHGs), and hazardous air pollutants( HAPs).
When gases such as nitrogen, oxygen, and argon must be stored and transported at extremely low temperatures, bellows sealed valves prevent leaks even under extreme fluctuations.
Types of Fugitive Emissions Volatile organic compounds, such as benzene, evaporate easily at room temperature, contributing to air pollution. When released, they can form ground-level ozone, a major component of smog, which negatively impacts air quality and human health.
GHGs, like carbon dioxide and methane, drive climate change; carbon dioxide is more prevalent, and methane is at least 28 times more potent.
Hazardous air pollutants, including formaldehyde, are toxic even at low levels and can cause long-term health problems, such as cancer, reproductive issues, and nervous system damage.
Although small, leaks across a large facility accumulate significant volumes, especially in continuous operations. Some fugitive emissions contain hazardous chemicals that can cause health problems upon inhalation or through skin contact. Others are highly flammable; even small leaks can trigger explosions, especially in confined spaces or near ignition sources.
Additionally, acids and other caustic substances can corrode metal surfaces, eventually causing equipment failures, larger leaks, malfunctions, or safety hazards.
Regulations Beyond safety hazards, fugitive emissions have broad environmental implications. To address this, governments worldwide have enacted strict regulations. In the U. S., the Environmental Protection Agency( EPA) enforces several rules under the Clean Air Act( CAA) to curb emissions from various industrial sources, including equipment leaks.
The EPA’ s Clean Water Act( CWA) also indirectly addresses fugitive emissions by controlling pollution that contributes to stormwater runoff. The European Union regulates fugitive emissions through its Industrial Emissions Directive( IED).
22 Valve World Americas | October 2025 | www. valve-world-americas. com