The API 2350 committee is meeting to publish its fifth edition of the Standard for Overfill Prevention Process (OPP). The latest revision will be based largely on the previous edition, and it will focus on expanding safety clarifications and helping readers make sense of the terminology and numerous options available for an OPP. The standards were last reviewed in 2012.
API 2350 is meant to be a simplified standard compared to IEC 61511, providing overall guidance on the safety requirements to prevent overfill and product loss. The new revision has been expanded with references and examples to supplement the standard normative references. API's goal is to provide guidance for owners/operators, understanding that facility size and scope vary greatly. The standards provide users with tools to apply according to their needs and requirements.
API 2350 applies to aboveground storage tanks with capacities greater than 1,320 gallons; store Class I, II or III flammable or combustible liquids; and receive liquids from mainline pipelines or marine vessels. The standards address management, risk assessment, defining operational parameters, OPP procedure requirements and equipment systems supporting OPP, including the automated overfill prevention system (AOPS).
API 2350 outlines several levels of concern (LOCs) that allow owners/operators to set appropriate levels for alerts, alarms or other AOPS functions. Typical levels of concern on tanks include maximum working level, the highest product level to which the tank may routinely be filled during normal operations; high-high level, an emergency action alarm that alerts users when the level is approaching critical high level; and critical high level, the highest level product can reach in the tank without detrimental outcomes including tank damage and overflow. LOCs are designed to give owners/operators ample opportunities to identify potential problems and prevent overfills before they happen.
Ultimately, the API 2350 standards are meant to promote process safety, On the front line of tank safety is the equipment owners/operators install to alert them when their media reaches LOCs. Since API 2350 was last updated, several new level measurement technologies have hit the market. The new standards make up an updated annex of tank gauging equipment to include these instruments.
One of the most common technologies for tank level measurement is through-air radar. These sensors have a lot to offer: They are noncontact and relatively easy to install and configure, and most instrumentation manufacturers carry through-air radar detectors that specialize in measuring difficult liquids. In the past two years, a few of instrumentation's major players have launched through-air radar devices that operate with 80 gigahertz (GHz) transmission frequency. These new sensors represent a major step forward in safety.
First, 80 GHz through-air radar sensors arrive from the factory ready for installation. Owners/operators can set their measurement range and walk away -- no special parameters necessary. Providing a trustworthy measurement right out of the box eliminates human error and increases safety. Second, these sensors (and, to be fair, many sensors with a lower transmission frequency) allow for remote verification of readings. Bluetooth and other technologies allow users to check their level readings without climbing ladders or otherwise endangering themselves. Again, this is progress in terms of safety.
Updates to API 2350 are coming. Any tank farm operator reading this should feel comforted. If the operators have been meeting the standards of the fourth edition, the fifth edition will feel comfortable and familiar. The standards are designed with you in mind. API has developed relevant practices that reflect the realities of your process and updated equipment information to reflect the realities of the market.
For more information, visit www.vega.com or contact Jennifer McGinnis at j.mcginnis@vega.com or (513) 272-0131.
