In 1996, Tosco Incorporated was searching for a method of reducing fugitive emissions from seven gasoline (Note 1) storage tanks at its Rodeo, California refinery. The assignment was given to Marty Clift, A Consulting Engineer in the petrochemical industry. At that time, he found that no manufacturer offered a weight-loaded pressure-vacuum vent or emergency vent that was capable of reliably keeping fugitive emissions under 500 ppm. He would later turn to The Protectoseal Company, of Bensenville, Illinois, to develop an effective solution.

The expertise that Mr. Clift developed, in the course of his investigation, led HYDROCARBON PROCESSING magazine to publish he article on, "Reducing Fugitive Emissions from Tank Roof Appurtenances" in their May 1997 issue. The conclusion of Mr. Clift's article stated, "No current technology will positively reduce fugitive emissions from tank roof appurtenances for long periods of time without excessive maintenance. . ."

Mr. Clift contacted several manufacturers of storage tank hardware, but the attitude and cooperation of the people at Protectoseal convinced him that Protectoseal was his best choice for a supplier. Protectoseal is recognized as a leading worldwide manufacturer of Vapor Control Products for pressure / vacuum relief and fire prevention in low-pressure storage tanks and related systems. Mr. Clift proposed a joint effort with Protectoseal to develop tank appurtenance hardware that would keep fugitive emissions below 500 ppm over a long period of time, with little or no maintenance.

As Mr. Clift tells the story, "In our early efforts at the refinery, we learned how to keep fugitive emissions from pressure / vacuum vents low for a little over a month with conventional vents, but we were constantly sending crews on top of the tanks to reseal the vents. I needed fugitive-emission-tight pressure / vacuum vents, emergency vents and gauge hatches for the refinery storage tanks that would minimize fugitive emissions AND reduce maintenance costs. I knew that I could rely on Protectoseal to work with us in engineering and manufacturing the equipment needed to meet our specific low leakage requirements".

Mr. Clift and the Protectoseal engineers worked together to develop, test and refine relief vents and gauge hatches incorporating a liquid seal design. Following an initial period of testing and refinement, the vents were installed permanently, and have solved Tosco's critical need to maintain emissions below 500 PPM and reduce maintenance on the specific configuration of their tanks.

The Protectoseal liquid seal vents have now been in service on seven storage tanks at the Tosco Rodeo Refinery for over a year, with some vents having been in place for over two years. The vents are performing flawlessly, with emission readings in the 1 PPM to 100 PPM range.

Protectoseal's Sales, Customer Service and Engineering Departments are prepared to help you select the best tank vents, tank blanketing valves, and flame and detonation arresters for your vapor control requirements

Notes: (1) The "gasoline storage tanks" hold various intermediate components of gasoline, as well as some by-products such as "sour" water. Most of the seven tanks have Hydrogen Sulfide concentrations in the vapor space of 2 to 5%.