Method for inspecting an internal floating roof in a liquid-containing storage tank

A method for inspecting a gap between a seal of an internal floating roof in a liquid-containing storage tank and a tank side wall, comprising:

• (a) inserting a camera into a vapor space above the floating roof at a predetermined distance above an upper surface of the floating roof;
• (b) projecting a plurality of substantially parallel laser beams onto the seal associated with the upper surface of the floating roof;
• (c) projecting another laser beam at an angle different from the substantially parallel laser beams;
• (d) viewing an illumination pattern formed by at least a portion of the laser beams on the seal;
• (e) calculating a length between the pattern formed by the laser beams and a spot illuminated on the seal or on a wall surface of the storage tank by the another laser beam, wherein said length relates to a distance of separation between the seal and the tank side wall.

A method for inspecting an internal floating roof in a liquid-containing storage tank, comprising:

• (a) inserting a camera into a liquid-containing volume of the liquid-containing storage tank at a predetermined distance;
• (b) directing the camera toward an underside surface of the floating roof or a seal associated therewith;
• (c) projecting a plurality of substantially parallel laser beams onto the underside surface of the floating roof or the seal;
• (d) projecting another laser beam at an angle different from the substantially parallel laser beams;
• (e) viewing an illumination pattern formed by the laser beams on the surface;
• (f) calculating a length between the pattern formed by the laser beams and a spot illuminated on the surface by the another laser beam, wherein said length relates to a size of a defect in the floating roof or seal or a distance of separation between the seal or the floating roof and the wall surface of the storage tank.

A method for inspecting an internal floating roof or a seal associated therewith in a liquid-containing storage tank, comprising:

• (a) inserting a camera into a liquid-containing volume of the liquid-containing storage tank wherein said camera is mounted for tiltable movement onto an inspection vehicle;
• (b) directing the camera toward a target on the underside surface of the floating roof or the seal;
• and
• (c) electronically transmitting a visual image of the target for processing or analyzing outside of the liquid-containing volume.