Melt-processible rubber used in fuel storage tanks.

Increasingly, owners and operators of underground fuel storage tanks are being pressured to further reduce the incidence of fuel spills and groundwater intrusions, according to the company. As a result, manufacturers are said to be developing new products and technology to meet the demands of the end users and regulatory agencies. Diversified Products has used the foundation established by its predecessor, Weaver Manufacturing, to create a more durable product without compromising performance or significantly impacting production costs.

Diversified Products manufactures flexible penetration fittings, or bulkhead seals, that protect secondary fuel storage systems and underground fuel tanks from costly leaks, safeguarding the environment in the process. These seals are installed on fuel storage systems where fuel-carrying pipes pass through containment walls. These seals are in place to prevent the leaking of fuel into and through the secondary containment systems (sumps), whose job it is to catch any spilled fuel before it leaches into the groundwater, while providing an additional barrier to groundwater intrusion.

In the 1990s, engineers from Weaver Manufacturing are said to have realized that the thermoset nitrile rubber most commonly used in fuel-containment system bulkhead seals had a limited life expectancy that, in effect, undermined their reliability.

To meet the parallel challenges of environmental safety, and preserving and growing the company, Weaver's engineers knew an alternative material had to be found. Melt-processible rubber (MPR) was said to show great promise. The material, Alcryn MPR, during testing is said to have shown strong durability and resistance to oil and fuels.

Test results from the manufacturer of Alcryn are said to have confirmed a clear advantage over other available materials. In exposure tests using ASTM Oil No. 1 and other typical hydrocarbon-based fluids, Alcryn MPR was rated as "A," with the fluid having little or no effect on the material. For fuels like unleaded gasoline and diesel, the effect is said to be rated as minor or moderate.

Initial bulkhead designs featuring TPEs and TPRs often failed for several reasons, including long-term exposure to the fuel, as well as the freezing, thawing and refreezing of the systems in the northern climates, according to the company. Additional failures are said to have occurred because of cold drawing or creeping of the plastic material away from the point of pressure. Diversified Products is said to have eliminated the material failures by developing a double-sided barrier made with MPR. The seal is produced in Diversified Products' in-house injection molding facility.

Advanced Polymer Alloys

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