Tank Overfill Protection

When Chevron decided to upgrade all of its storage tank overfill protection systems in South Africa, Africa and Pakistan, they chose Omni16C safety rated alarm annunciators from Omniflex to provide the vital alarm function. Chevron is one of the world's largest integrated energy companies, conducting business in more than 100 countries. They are engaged in every aspect of the oil and natural gas industry, including exploration and production, manufacturing, marketing and transportation, chemicals, manu-facturing and sales, geothermal, power generation and renewables. Chevron is committed to the highest health, environment and safety standards in every country in which it operates. Throughout the world, the company selects and applies best practices and lessons learned from one region to another. On 11th December, 2005 a series of major explosions occurred at the Buncefield oil storage and transfer depot on the outskirts of London. The explosions occurred as a result of inadvertent overflow of one of the unleaded motor fuel storage tanks on the site. This incident lead to the release of a report: “Recommendations on the design and operation of fuel storage sites”. In the light of this Buncefield report, the industry began to review its best practice with a view to preventing the reoccurrence of such a disaster. Chevron, as a result of its ongoing commitment to health, safety and the environment, embarked upon a series of overfill protection projects to ensure compliance of all its storage sites in line with the Buncefield recommendations. After careful review a number of options, Chevron chose Omniflex to provide the alarm systems for these projects. The solution was based upon the SIL1 assessed Omni16C alarm annunciator. Installations based upon this solution are completed or under-way in storage sites throughout Africa and Pakistan. Omniflex provided full system integration and supply of pre-wired panels with Omni16 Annunciators for the applications. The Omni16C Alarm Annunciators were supplied in panels equipped for 16, 24, or 32 monitor points from the fail safe level measure-ment transmitters fitted to the Bulk Terminal Storage Tanks. The level transmitters provide contact outputs to High and High-High level alarms which are hardwired to the safety rated Omni16C Annunciators. The Omni16C provides the audible and visual alarm status indication required to draw operational staff’s attention. In some cases a GSM based SMS alarm message is also generated to draw attention of operational staff off site. The SMS Alarm messaging was implemented using the Omniflex Silent Sentry Alarm Monitor connected directly to the Modbus communications port of the Omni16C alarm annunciators. The SMS alarm messages require an acknowledgement just as the annunciators do. The Silent Sentry Alarm Monitor will escalate unacknowledged alarms to up to 10 other mobile phone numbers in its escalation list ensuring that alarms are re-sponded to. Dev Moodley, Terminal Automa-tion Coordinator for Chevron Africa-Europe-Pakistan region had this to say: “Omniflex was selected for it’s technical experience and expertise with annunciator systems for the petrochemical industry, it’s distribution support network for Africa and Pakistan and it’s feature rich product which will allow us to integrate Omni16C into our future control and monitoring strategy roll out. “We place the highest priority on the safety and health of our workforce and the people in the communities where we operate, on the environment, and on the reliability and efficiency of our operations. “Our Operational Excellence Management System (OEMS) focuses on leadership accountabil-ity and on a management system process that is integrated into our business planning. It also inte-grates a comprehensive set of expectations for operational excellence to achieve world-class health,

For more information on Tank Overfill Protection talk to Omniflex UK Limited