Managing Fugitive Emissions from Control Valves and Automated On-Off Valves in Hexane-Based Oilseed Processing
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Managing Fugitive Emissions from Control Valves and Automated On-Off Valves in Hexane-Based Oilseed Processing

Author: Relevant Industrial
Date: December 12, 2023

The production of oils from seeds, such as flax and linseed, is a complex process involving various stages, including separation, extraction and purification. One commonly used solvent in this process is hexane due to its excellent oil-solvent properties. However, the handling of hexane and the associated fugitive emissions can present significant environmental and safety challenges. This article explores the importance of managing fugitive emissions from control valves and automated on-off valves in hexane-based oilseed processing. It also highlights the relevance of international standards like ISO 15848 and API 641 in minimizing fugitive emissions and the role of valves, particularly the Flowserve Worcester Automated On-Off Valves and Schubert and Salzer Control Valves, in achieving these goals. 

The Role of Hexane in Oilseed Processing 

Hexane, a volatile organic compound (VOC), is an ideal solvent for extracting oils from seeds. Hexane is highly effective at dissolving oil components, resulting in an oil-hexane mixture that can be further processed to obtain desired oil products, making it a preferred choice for the extraction process. It's low boiling point of 69C, 156F, allows the solvent to remain a liquid at ambient temperatures, allowing for minimal energy to initiate evaporation, distillation, and recovery. However, the handling of hexane poses environmental and safety challenges, primarily concerning fugitive emissions. 

Understanding Fugitive Emissions 

Fugitive emissions refer to unintentional releases of gases, vapors, or mists into the atmosphere. In oilseed processing, fugitive emissions can occur during various phases, such as extraction, transportation, and storage of hexane. These emissions have significant implications: 

  • Environmental Impact: Hexane is a known contributor to air pollution, smog formation, and greenhouse gas emissions. Its release into the environment can negatively impact ecosystems and human health. 

  • Safety Concerns: Hexane is highly flammable, making fugitive emissions a significant fire and explosion hazard. Worker exposure to hexane vapors can result in respiratory problems, skin irritations, and nervous system damage. 

  • Regulatory Compliance: Excessive fugitive emissions can lead to regulatory fines and legal consequences, increasing operating costs for processors. 

Relevance of ISO 15848 and API 641 Standards 

International standards play a crucial role in addressing fugitive emissions. Two key standards, ISO 15848 and API 641, are particularly relevant to valve selection in the context of hexane-based oilseed processing: 

ISO 15848: This standard focuses on testing and classifying the emissions performance of valves used in industries like oil and gas. It sets stringent criteria for fugitive emissions, categorizing valves based on leakage rates. ISO 15848-1 covers measurement techniques, while ISO 15848-2 provides production testing procedures. These standards ensure that control valves and automated on-off valves meet strict emissions control requirements. 

API 641: API 641, developed by the American Petroleum Institute (API), is a rigorous standard for quarter-turn valves (including ball valves, butterfly valves, and plug valves). It evaluates the emissions performance of these valves in low-pressure and high-pressure applications at elevated temperatures. API 641-certified valves demonstrate their ability to limit fugitive emissions effectively. 

Minimizing Fugitive Emissions with Proper Valve Selection 

The choice of control valves and automated on-off valves plays a crucial role in reducing fugitive emissions. Valve manufacturers like Flowserve's Worcester and Schubert and Salzer offer solutions designed to meet or exceed these stringent emissions standards. 

Flowserve Worcester Automated On-Off Valves: Flowserve's Worcester valves are engineered to provide exceptional performance in managing fugitive emissions. These valves feature advanced sealing technologies, such as bellows-sealed designs and low-emission packing systems. Their design ensures that hazardous fluids like hexane are effectively contained, minimizing the risk of fugitive emissions. 

Schubert and Salzer Control Valves: Schubert and Salzer Control Valves are known for their precise control and low-emission capabilities. These valves are designed to maintain tight shut-off and low leakage rates, making them suitable for applications where fugitive emissions must be minimized. 


The management of fugitive emissions from control valves and automated on-off valves is essential in hexane-based oilseed processing. Strict adherence to international standards like ISO 15848 and API 641 ensures that fugitive emissions are minimized to protect the environment, workers, and to comply with regulatory requirements. Valve selection is a critical factor in achieving this goal, and manufacturers like Flowserve's Worcester and Schubert and Salzer offer fit-for-purpose solutions designed to meet the rigorous demands of the oilseed processing industry. By reducing fugitive emissions, these valves contribute to safer and more environmentally responsible oilseed processing practices, benefiting both the industry and society at large.