What be the best mitigation process if a tank in service with an external floating roof and has a leak on the double deck pontoon? The leak has penetrated the inner or annular pontoon. How reliable are pontoon liners? Would it be able to float a 82,000 lb. floating roof?
Fill the pontoons with foam. Depending on the product in the tank that would be a way to go. Unicoat makes a foam for pontoons.  foam is great, but the problem with foam is the removal of it when you're ready to make a permanent repair.
what i've switched to is the "McDonalds balls". they're the plastic hollow balls that you fill the pontoon with to displace the product with air. They're a quick, cheap solution that is easily removed and reusable when the tank comes out of service and a permanent repair is made.
I'll have to look around to find our supplier of these ball valves.
Either solution will be just as effective. the seller to me with the plastic balls was the fact that i can reuse them as many times as i want.

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