FUGITIVE EMISSIONS
Valve packing sets vs packing lengths for fugitive emission applications
During the refurbishment of valves, two primary sealing solutions are typically employed. What are the advantages and disadvantages of packing sets vs packing lengths?
By Ralf Vogel, ESA
Fugitive emissions, which refer to the unintentional release of gases or liquids from pressurised systems, pose a significant challenge in industrial settings, especially within the oil and gas, chemical, and power generation industries. Effective sealing of valves is essential for managing these emissions. During the refurbishment of valves in site revisions, two primary sealing solutions are typically employed. What are there advantages and disadvantages?
Valve packing sets
Valve packing sets consist of pre-cut and premeasured rings of packing material tailored to fit specific valve stem and housing dimensions. These sets are generally designed to comply with strict fugitive emission regulations, including ISO 15848-1, API 622, and EPA LDAR standards. The advantages of packing sets for fugitive emission control include:
• Precision and consistency – The pre-cut nature of packing sets guarantees uniform compression and mitigates the risk of incorrect installation, resulting in enhanced sealing performance.
• Compliance with standards – Numerous packing sets are engineered and tested to meet international fugitive emission standards, ensuring compliance with regulations.
• Enhanced sealing performance – These sets are crafted for optimal seating, which reduces leak paths and minimizes emissions.
• Reduced installation errors – The pre-cut design helps avoid over- or under-packing, which can cause excessive friction or insufficient sealing.
• Longer service life – Engineered packing sets often utilize high-purity graphite or hybrid materials that improve durability and decrease maintenance intervals.
• Easier and quicker installation.
Packing lengths
Packing lengths are available in continuous spools or coils, requiring manual cutting and installation. They provide flexibility for various applications and can be customised to fit different valve types. The challenges of packing lengths in fugitive emission applications include:
• Inconsistent Installation – Manual cutting and packing may result in uneven compression, heightening the risk of emissions.
• Potential for gaps and leak paths – Improperly cut or installed packing can lead to leak paths, complicating the achievement of low fugitive emissions.
• Increased maintenance requirements – Packing lengths typically necessitate more regular adjustments and replacements because of uneven wear.
• Restricted compliance – If not installed and compressed correctly, packing lengths might have difficulty adhering to strict fugitive emission regulations.
Table 1 illustrates the differences discussed as well as additional ones.
Figure1. Leakage results for expanded graphite packing lengths / sets
60 Valve World August 2025 www. valve-world. net