Floating roof support legs with vapor seals

A storage tank assembly comprising (1) a volatile fluid storage tank having an open top, (2) a floating roof defining a generally horizontal plane for closing said open top, and (3),

• a plurality of support columns, each comprising:
• a. an inner pipe formed by a cylindrical wall having top and bottom ends and having a central longitudinal axis therethrough,
• b. an outer pipe secured to said floating roof and extending below and generally perpendicular to the plane of said roof, said outer pipe formed by a cylindrical wall having top and bottom ends and having a central longitudinal axis therethrough, said outer pipe surrounding and being movable axially on said inner pipe between different predetermined axial locations relative to said inner pipe, and with a generally annular space defined between said inner and outer pipes, said generally annular space having opposite top and bottom ends,
• c. a coupling element fixed to said outer pipe and releasably attachable to said inner pipe at selected ones of said predetermined positions along its length, which thereby fixes said outer pipe and floating roof secured to said outer pipe at a said selected predetermined axial positions relative to said inner pipe and fixes said floating roof at a predetermined elevation above the bottom end of said inner pipe, and
• d. a primary seal formed as an elastic cylindrical sleeve having upper and lower parts each with bore surfaces, said upper part bore surface being adapted to slidably engage said inner pipe outer surface, and said lower part bore surface adapted to resiliently engage said top end outer surface of said outer pipe, said primary seal further comprising a radially inward extending rib situated axially between said upper and lower part bore surfaces and extending transversely across and closing said top end of said annular space when said primary seal is positioned to engage said inner and outer pipes.

A floating roof and support column assembly, comprising a floating roof defining a generally horizontal plane and having top and bottom surfaces and a plurality of support columns, each of said support columns comprising:

• a. an inner pipe formed by a cylindrical wall having top and bottom ends and having a central longitudinal axis therethrough, and
• b. an outer pipe securable to said floating roof to extend below and generally perpendicular to the plane of said roof, said outer pipe formed by a cylindrical wall having top and bottom ends of a having a central longitudinal axis therethrough, said outer pipe surrounding and being movable axially on said inner pipe with a generally annular space defined between said inner and outer pipes, said generally annular space having opposite top and bottom ends, each of said outer support columns extending downward from said floating roof and spaced apart laterally from each other,
• c. said outer pipe having a first set of coaxial holes extending transversely through opposite sides of said wall of said outer pipe,
• d. said inner pipe having a second set of coaxial holes extending transversely through opposite sides of said wall of said inner pipe,
• e. said first and second sets of holes dimensioned to receive a pin extendible generally perpendicular to said central longitudinal axes of said pipes and through both sets at once when said first and second sets of holes are axially aligned move, which thereby fixes said outer pipe and floating roof secured to said outer pipe at a predetermined axial position relative to said inner pipe, and
• f. each of said support columns further comprising a primary seal formed as an elastic cylindrical sleeve having upper and lower parts each with bore surfaces, said upper part bore surface being adapted to slidably engage said inner pipe outer surface, and said lower part bore surface adapted to resiliently engage said top end outer surface of said outer pipe, said primary seal further comprising a radially inward extending rib situated axially between said upper and lower part bore surfaces and extending transversely across and closing said top end of said annular space when said primary seal is positioned to engage said inner and outer pipes.