BOILERS, PUMPS & VALVES


REDUCING FUGITIVE EMISSIONS Randy Rieken, global market manager, Oil, Gas &


Chemicals, Swagelok Company, examines how low-emissions valves can help ensure regulatory compliance


F


ugitive emissions, or uncontrolled emissions of gases from process equipment, are an


important topic for chemical processing and refining facilities because they can negatively impact profitability and compliance with environmental regulations. Volatile organic compounds (VOCs), such as


benzene, methane and ethanol, are the main gases of concern when it comes to fugitive emissions as they can jeopardize air quality, contributing to the formation of ozone. To combat the issue, governments around the world are starting to require plants to institute enhanced leak detection and repair programs (LDAR) and to only procure low-emissions (Low-E) valves that are tested to not leak in excess of guidelines during thermal and pressure testing cycles.


Figure 1 Figure 2


available from the American Petroleum Institute (API) and International Standards Organization (ISO) for determining if the valve should be classified as ‘low emissions’ as seen in Table 1, below. API testing provides a simple pass or


fail result. The valve is either certified as a Low-E valve or not. However, valve purchasers should be aware that the ISO test methodology allows for various ‘class’ ratings of valves related to how they perform during testing. These ISO classes can allow a valve


to be considered and labelled ‘Low-E,’ yet not meet the ‘100 ppm or less’


However, most regulatory language leaves what constitutes a Low-E valve up to the plant. There are several methods by which a valve


can be classified as a Low-E valve, and it is the decision of the plant to accept either of the following from the manufacturer of the valve: 1. A written guarantee that the valve will not leak


above 100 parts per million (ppm) for five years. This is a seemingly simple solution. However,


a plant operator should consider the ramifications if the valves do leak. With fines that can reach as high as $10,000 per day per incident for noncompliance, relying on a manufacturer’s guarantee leaves a plant open to the possibility that, either willingly or not, the manufacturer could continue to provide valves that leak in excess of 100 ppm. 2. A written guarantee, certification, or


equivalent documentation that the valve has been tested pursuant to generally accepted good engineering practices and has been found to be leaking at no greater than 100 ppm. This means plant and environmental engineers


IMPLEMENTING ENHANCED LDAR AND LOW-E VALVES The purpose of enhanced LDAR programs is to emulate the periodic leak detection and oversight methods of various government agencies. For valves, an audit can consist of both a paper audit as well as field testing for emissions (Figure 1). Plants implementing an enhanced LDAR program


primarily seek to lower fugitive emissions through the following methods: • Instituting a comprehensive plan whereby leaks are identified through in situ testing of valves and other connections (Figure 2)


• Identifying, documenting, and repairing leaks within a defined timeframe (Figure 3)


• Lowering allowable leak limits for valves, connections and pumps. As previously mentioned, valves procured for


future maintenance, repair and operations (MRO), as well as new projects, must be Low-E valves.


12 ENERGY MANAGEMENT - Winter 2021


are left to determine what constitutes ‘generally accepted good engineering practices,’ as well as if the test replicates process conditions based on what the manufacturer provides. Ideally, testing should be conducted using a third-party laboratory and not by the valve manufacturer to ensure unbiased results. A valve certification should then be made available from the valve manufacturer as documentation, including a seal from the third- party lab, the testing location, and the results.


VALVE EMISSIONS TEST METHODS To aid in ensuring standardized results when it comes to valve emissions, there are industry tests


Test API 624


API 641 ISO 15848-1


Valves Tested


Rising Stem Valves Ball Valves


Industrial Valves


Test Media Methane


Methane


Methane or Helium


Description


Type testing of rising stem valves equipped with graphite packaging of fugitive emissions


Testing of quarter-turn valves for fugitive emissions


Measurement, test, and qualification procedures for fugitive emissions


Table 1. Industry Tests for Determining Low-Emissions Valve Classifications www.energymanagementmag.co.uk


leak rate requirement. Tightness Class CM, for example, describes a ‘low-emission’ valve that leaks in excess of 100 ppm methane, but less than 500 ppm methane.


GET AHEAD OF EMISSIONS REQUIREMENTS Whether you are designing new systems or seeking to improve your LDAR program, choosing Low-E-certified valves is critical to reducing fugitive emissions. Being proactive and specifying certified Low-E


valves prior to any environmental enforcement action prevents costly retrofit expenses and helps you stay compliant with current environmental best practices. Having clear instructions and procedures on what valves to order for VOC service also helps protect both the environment and your operational integrity.


Swagelok www.swagelok.com


Figure 3


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