A wall box includes an enclosure having a base and a cover connected to the base. The base and the cover enclose an interior region. The wall box further includes a plurality of fiber optic adapters mounted to the enclosure. The fiber optic adapters include an inner port positioned inside the interior region and an outer port positioned at an outer surface of the enclosure. A tray stack is mounted within the interior region. The tray stack includes a tray mount pivotally connected to the enclosure. The tray mount includes a top surface and an oppositely disposed bottom surface. A first splice tray mounting area is disposed on the top surface and a second splice tray mounting area is disposed on the bottom surface. A plurality of trays is disposed in the first splice tray mounting area. A tray is disposed in the second splice tray mounting area.

A floating roof for an oil tank includes a beam unit and a plurality of float units secured on the beam unit. The beam unit includes a plurality of longitudinal beams and a plurality of transverse beams. Each of the longitudinal beams has an upright wall provided with a plurality of first transverse holes. Each of the transverse beams is located between two of the longitudinal beams and has a bottom plate and two transverse side plates. Each of the two transverse side plates has a second transverse hole. The beam unit further includes a plurality of bolts each extending through one of the first transverse holes and the second transverse hole of each of the transverse side plates, and a plurality of nuts screwed onto the bolts, so that the longitudinal beams and the transverse beams are combined together.

Floating roof tank for a volatile liquid have an outer roof and an internal floating roof with a primary seal with a support such that when the tank is empty, the floating roof will rest on the support whether the tank is in a vertical or horizontal position. The support enables the tank to be transported in a horizontal position without damage to the seal. The floating roof tank with support can be configured as a conical tank, flat bottom tank or slant bottom tank. The floating roof tank can also include a cleaning system and a flush mounted manway cover.

Floating roof tank for a volatile liquid have an outer roof and an internal floating roof with a primary seal with a support such that when the tank is empty, the floating roof will rest on the support whether the tank is in a vertical or horizontal position. The support enables the tank to be transported in a horizontal position without damage to the seal. The floating roof tank with support can be configured as a conical tank, flat bottom tank or slant bottom tank. The floating roof tank can also include a cleaning system and a flush mounted manway cover.

A sludge digester including a vessel and floating cover. The vessel includes a sidewall and an interior volume configured to receive and contain sludge. According to one embodiment, the cover comprises a frame structure that is constructed and arranged to form a skirt member formed at a periphery of the cover and extending downwardly into the vessel, and a continuous ballast ring attached to a lower portion of the skirt member and configured to form a trough member with an interior surface of the skirt member. The sludge digester may also include a guide system coupled to the sidewall and the skirt member and configured to allow vertical displacement of the cover with change in volume of at least one of a gas and a sludge contained in the vessel beneath the cover.

A sludge digester including a vessel and floating cover. The vessel includes a sidewall and an interior volume configured to receive and contain sludge. According to one embodiment, the cover comprises a frame structure that is constructed and arranged to form a skirt member formed at a periphery of the cover and extending downwardly into the vessel, and a continuous ballast ring attached to a lower portion of the skirt member and configured to form a trough member with an interior surface of the skirt member. The sludge digester may also include a guide system coupled to the sidewall and the skirt member and configured to allow vertical displacement of the cover with change in volume of at least one of a gas and a sludge contained in the vessel beneath the cover.

Method and apparatus for cribbing a floating roof included in a storage tank whereby a first and a first opposite force are applied between a floor in the storage tank and an internal surface of the floating roof. An additional set of forces are also provided and are constrained according to the first and first opposite force, not only in magnitude, but in position. By constraining these forces to be applied orthogonally to the floating roof, horizontal shear forces can be resisted thus reducing the likelihood of failure of a cribbing unit.

Method and apparatus for cribbing a floating roof included in a storage tank whereby a first and a first opposite force are applied between a floor in the storage tank and an internal surface of the floating roof. An additional set of forces are also provided and are constrained according to the first and first opposite force, not only in magnitude, but in position. By constraining these forces to be applied orthogonally to the floating roof, horizontal shear forces can be resisted thus reducing the likelihood of failure of a cribbing unit.

An automatic aeration device includes a first floating roof, a second floating roof and a movable valve. The first floating roof has a through hole and a first enclosure. The second floating roof is disposed in the through hole and has a second enclosure. The movable valve is disposed above the first floating roof and the second floating roof and has a plate which has an outer wall and an inner wall. The outer wall is mounted in the first enclosure and has a plurality of first vent holes. The inner wall is mounted in the second enclosure and has a plurality of second vent holes. The automatic aeration device further includes a plurality of balls mounted between the first enclosure and the outer wall, and mounted between the second enclosure and the inner wall.

An automatic aeration device includes a first floating roof, a second floating roof and a movable valve. The first floating roof has a through hole and a first enclosure. The second floating roof is disposed in the through hole and has a second enclosure. The movable valve is disposed above the first floating roof and the second floating roof and has a plate which has an outer wall and an inner wall. The outer wall is mounted in the first enclosure and has a plurality of first vent holes. The inner wall is mounted in the second enclosure and has a plurality of second vent holes. The automatic aeration device further includes a plurality of balls mounted between the first enclosure and the outer wall, and mounted between the second enclosure and the inner wall.