Abstract: A floating roof storage tank having an upstanding tank shell for containing liquid to be stored and having therein a floating roof floating on the surface of the stored liquid, a primary seal interconnecting the floating roof and the tank shell, and an annular secondary seal extending between the floating roof and the tank shell providing a gas tight seal and weather shield for the primary seal, sealant is used at the inner end of the secondary seal mounted to the floating tank to ensure the gas tight connection thereat, and a tapered and rounded flexible free or outer end of the secondary seal ensures that irregularities in the tank shell do not permit vapors to escape; support structures maintain the secondary seal in its desired configuration and a variety of structures are disclosed for maintaining adjacent arcuate sections of the secondary seal in fixed and sealed relation.

Abstract: In a dry seal gasholder cylindrical storage tank with a vertically-movable piston, an improved piston leveling system includes a vertically-movable weight outside the tank and connected by equal-length cables to spaced-apart support points on the piston at different distances from the weight. An array of guide sheaves on the tank define equal-length cable paths. The cables are pivotally coupled to spaced-apart points on a coupling plate to which a pair of attachment plates on the weight are also pivotally connected. Apertures in the attachment plates and the coupling plate are disposable in registry with one another for receiving a pin therethrough when the cable attachment points are in horizontal alignment, thereby to indicate equal tension in the cables.

Abstract: A floating roof storage tank having an upstanding tank shell for containing liquid to be stored and having therein a floating roof floating on the surface of the stored liquid, a metal shoe carried by the floating roof and extending around the tank shell, a primary seal interconnecting the floating roof and the metal shoe, a plurality of seal support members shiftably mounted upon the metal shoe at the upper end thereof, a secondary seal extending between the upper rim of the floating roof and the seal support members and beyond the seal support members and against the inner surface of the tank shell; the seal support members are shiftable away from the tank shell a distance to permit inspection of the primary seal therebelow; limit structure acting between the metal shoe and the seal support members limit movement thereof to prevent the seal support members from contacting the tank shell.

Abstract: An expansible dry seal gasholder includes a piston disposed within a container side wall and a plurality of generally annular fender structures disposed between the piston and the side wall and spaced therefrom and from each other, with flexible fabric sealing members interconnecting the piston and the fender structures and the side wall and closing the spaces therebetween. Respectively pivotally mounted between the arms of a clevis at the top of each fender structure are generally L-shaped latch members, each having one end thereof connected by a roller chain to the upper end of the next innermost fender structure, with the latch member of the innermost fender structure being connected to the upper end of the piston. The clevis brackets are adjustable effectively to vary the lengths of the chains.