Patent ID: 7849917

Claim:
A lower valve assembly capable of being installed within an oil pipe casing, the valve assembly having: a body with an interior, a top, and a bottom; a through passage extending through the body from an upper opening to a lower opening; and a seal; the through passage having at least two segments each having portions and each being in fluid communication with each other, the at least two segments comprising a first segment and a second segment, the first segment defining a section of the through passage extending from the upper opening down into the interior and the second segment defining a section of the through passage extending from the interior to the lower opening, the seal being engaged to and in fluidic communication with both the first and the second segments, the portions of the first segment and second segment engaged to the seal being in a non-linear orientation relative to each other, the seal having a specific density greater than water but less than oil the seal having an open configuration allowing for the passage of fluid and a closed configuration preventing the passage of fluid, the seal assumes an open configuration in response to the buoyant forces produced when in contact with water, and assumes a closed configuration in response to the anti-buoyant forces produced when in contact with oil.