The liquid fertilizer industry commonly uses Flexible Polyvinyl Chloride (PVC) Secondary Containment Liners to meet state requirements for aboveground storage tanks. Most secondary containment methods act as catch containers, only contacting the product when it leaks from the tank. In contrast, a flexible internal PVC tank liner offers a different approach with added benefits.
Tank Liners are Primary Containment
PVC tank liners sit inside the aboveground storage tank, unlike most other secondary containment methods that are outside.
Because the tank liner holds the product, the PVC liner serves as the primary containment, while the tank acts as the secondary containment. Many states permit this design as long as the tank liner system includes leak monitoring capabilities.
You must implement logistical strategies when using a flexible tank liner to ensure the material withstands the product and its metal tank housing. Since the tank liner serves as primary containment, the product must be compatible with the PVC. Additionally, take care when filling or cleaning the liner to avoid introducing sharp objects.
The system suspends most flexible PVC tank liners from the top of the tank below the roof rafters. The liner integrates with the nozzles and manways to create a complete tank system. Additionally, the tank includes valve boxes with leak monitor ports to contain the product in case an inlet or outlet valve leaks or breaks.
Two Main Benefits of PVC Liners
Using a PVC tank liner offers two main benefits: longer tank life and lower cost for required containment.
The life span of a tank partly depends on how long the shell material and welds withstand exposure to the stored product, weather, and water. A PVC liner creates a barrier between the potentially corrosive liquid product and the tank shell and floor. This barrier reduces exposure to corrosive products, potentially increasing the tank’s life.
The second benefit of a PVC tank liner is the lower initial cost compared to other secondary containment methods. A double-walled tank, the purest form of secondary containment, requires double the steel to build, driving the price substantially higher.
A lined dike, the next choice in price, requires a significant amount of land beyond the tank size, adding to the initial cost. Operating costs also increase due to the disposal of rainwater that collects in the dike, and several states now require all dike liquids to be agronomically applied.
An internal flexible PVC liner is the most cost-effective secondary containment option compared to a double-walled tank or a lined dike. The liner material costs much less than steel, and liners don’t require additional land or incur extra operational costs.
Learn More
To learn more about the benefits of an internal PVC tank liner and whether it meets your state’s containment requirements, contact us at Heartland Tank Services, Inc.