secondary containment system

Abstract

A secondary containment system ( 1 ) for installing around a ground-based primary vessel ( 6 ), the secondary containment system comprising a bund ( 2 ) having a base panel ( 3 ) and an endless wall ( 4 ) defining an enclosure. The bund ( 2 ) is made from several prefabricated sections ( 2 a , 2 b , 2 c , 2 d ), each pre-fabricated section being itself made from one of more component parts ( 31 - 34, 41 - 48 ). When the pre-fabricated sections are assembled around the primary vessel a central opening ( 3 b ) is defined in the base panel ( 3 ), whereby inner edges ( 30 ) of the base panel ( 3 ) which define the central opening ( 3 b ) surround the primary vessel ( 6 ). The inner edges ( 30 ) are hermetically fastened to a substrate surface ( 50 ) on which the primary vessel ( 6 ) and the bund ( 2 ) are installed to form a continuous liquid-impermeable surface. The bund ( 2 ) also comprises a fire-proof cover ( 100, 170 ) covering the wall ( 4 ) for fire and UV protection.

1 . A secondary containment system for containing a substance released from a primary vessel, the secondary containment system comprising:
 a bund, the bund including a base panel having a central area and a peripheral area; and   an endless wall extending from the peripheral area of the base panel and surrounding the base panel thereby defining an enclosure, the endless wall having an inner face facing the central area of the base panel and an outer face facing away from the central area of the base panel; wherein the endless wall and the base panel are joined continuously and hermetically;   wherein the endless wall and the base panel are manufactured from a first material, the first material being liquid impermeable;   wherein an opening is formed in the central area of the base panel, the opening being sized and shaped so as to encompass a base portion of a primary vessel when the bund is assembled;   wherein the base panel comprises two or more component parts, each component part comprising an inner edge which defines a portion of the central opening, an outer portion remote the inner edge and a pair of opposing side edges connecting the inner edge and the outer portion;   wherein the component parts of the base panel are fixedly joined on assembly by joining the side edges of adjacent component parts, whereby the inner edges of the assembled component parts define the central opening, whereby the outer portions of the individual component parts define the peripheral area of the base panel and wherein seams defined between the adjacent side edges of component parts are hermetically sealed;   wherein the endless wall comprises two or more component parts, each component part comprising a free edge remote the base panel, a lower portion remote the free edge and a pair of opposing side edges connecting the free edge and the lower portion;   wherein the component parts of the endless wall are joined on assembly by fixedly joining the side edges of adjacent component parts, so that the endless wall surrounds the base panel, and wherein seams defined between the adjacent side edges of component parts are hermetically sealed; and   wherein a sealing arrangement is provided for forming upon assembly of the secondary containment system a hermetic seal between the inner edges of the base panel and a substrate surface on which the bund is to be installed, the substrate surface being also the support surface for the primary vessel;   wherein, a cover member is provided comprising at least one side wall covering the inner face of the endless wall and a cap portion covering the free edge of the endless wall, the cover member being made from a second material, the second material being fire-proof.   
     
     
         2 . A secondary containment system as claimed in  claim 1 , wherein:
 the cover member comprises a second side wall covering the outer face of the endless wall; and   the cap portion of the cover member has a longitudinal axis and a pair of opposing edges spaced laterally from the longitudinal axis, wherein each side wall depends from a respective edge to define a generally inverted U-shaped cross-section of the cover member; wherein the cover member is installed over the endless wall whereby the cap portion covers the free edge of the endless wall and the side walls cover respectively the inner and the outer faces of the endless wall.   
     
     
         3 . (canceled) 
     
     
         4 . A secondary containment system as claimed in  claim 2 , wherein a free portion of one or each side wall of the cover member remote the cap portion rests on the base panel. 
     
     
         5 . A secondary containment system as claimed in  claim 1 , wherein the side wall of the cover member at the inner face of the endless wall is spaced from the endless wall in the direction of the central area of the base panel, thereby defining a heat insulation gap between the inner face of the endless wall and the side wall. 
     
     
         6 . (canceled) 
     
     
         7 . A secondary containment system as claimed in  claim 5 , wherein a series of heat insulating panels are disposed in the heat insulation gap to form continuous layer of heat-insulation around the inner face of the endless wall. 
     
     
         8 . A secondary containment system as claimed in  claim 7 , wherein the heat insulation panel is pre-cast from a heat-insulating material. 
     
     
         9 . A secondary containment system as claimed in  claim 8 , wherein the heat-insulating material comprises LECA (lightweight expanded clay aggregate). 
     
     
         10 . A secondary containment system as claimed in  claim 5 , wherein the heat insulation gap is filled with a heat-insulating material. 
     
     
         11 . (canceled) 
     
     
         12 . A secondary containment system as claimed in  claim 1 , wherein the cover member is made from fireclay. 
     
     
         13 - 14 . (canceled) 
     
     
         15 . A secondary containment system as claimed in  claim 1 , wherein the cover member extends endlessly and concentrically around the endless wall. 
     
     
         16 . A secondary containment system as claimed in  claim 1 , wherein upon installation of the bund, the substrate surface remains exposed through the central opening and a continuous surface is formed by an upwardly facing surface of the base panel and by the substrate surface exposed through the central opening; and
 wherein the substrate surface is liquid-impermeable, so that when the bund is assembled, the base panel which is sealingly fastened to the substrate surface and the substrate surface exposed through the central opening of the base panel form a continuous hermetic base of the bund of the secondary containment system.   
     
     
         17 . (canceled) 
     
     
         18 . A secondary containment system as claimed in  claim 16 , wherein the sealing arrangement comprises a gasket member extending endlessly along the inner edges of the base panel for hermetically sealing any passage between the inner edges and the substrate surface. 
     
     
         19 . (canceled) 
     
     
         20 . A secondary containment system as claimed in  claim 18 , wherein the secondary containment system of the present invention also comprises a fixing arrangement for substantially immovably fastening the inner edges of the base panel of the bund to the substrate surface. 
     
     
         21 . A secondary containment system as claimed in  claim 20 , wherein the fixing arrangement comprises one or more fastening members for mechanically fastening the inner edges to the substrate surface. 
     
     
         22 - 26 . (canceled) 
     
     
         27 . A secondary containment system as claimed in  claim 18 , wherein the inner edges of the base panel and the gasket member each have an inwardly facing minor side face, and the thickness of the base panel and the thickness of the gasket member when compressed between the base panel and the substrate surface are such that when the base panel is sealingly fastened to the substrate surface, a receptacle is defined by the minor side faces of the inner edges of the base panel and the gasket member and by the portion of the substrate surface exposed through the central opening, wherein the combined width of the minor side faces of the inner edges of the base panel and the gasket member is sufficient to form a receptacle capable of receiving a sufficient amount liquid so that the seal formed by the gasket member can be monitored for a pre-determined period of time to leak-test the seal. 
     
     
         28 . A secondary containment system as claimed  claim 27 , wherein the base panel comprises a collar panel which includes the inner edges of the base panel which define the central opening in the base panel and peripheral edges outwardly spaced from the inner edges, wherein the component parts of the base panel comprise a further set of inner edges which on assembly of the component parts of the base panel surround and are fixedly hermetically sealed with the peripheral edges of the collar panel. 
     
     
         29 . A secondary containment system as claimed in  claim 28 , wherein the collar panel comprises two or more component parts, each component parts including a pair of opposing side edges extending between the inner edge and the peripheral edge of the component part of the collar panel, wherein the component parts of the collar panel are fixedly joined on assembly by joining the side edges of adjacent component parts, whereby the inner edges of the collar panel define the central opening and wherein seams defined between the adjacent side edges of the component parts of the collar panel are fixedly hermetically sealed; thereby allowing the seal formed by the gasket member to be leak-tested prior to assembling the base panel. 
     
     
         30 - 31 . (canceled) 
     
     
         32 . A secondary containment system as claimed in  claim 1 , wherein portions of the base panel containing the inner edges of the base panel extend upwardly from the remaining upwardly facing surface of the base panel and the central opening is defined on assembly of the bund by the inner edges of the base panel and by underside surfaces of the upwardly extending portions, wherein the central opening is sized and shaped so that the inner edges of the base panel surround upwardly extending surfaces of a pedestal structure on which a primary vessel rests, wherein the inner edges are sealingly fastened on assembly to the upwardly extending surfaces of the pedestal structure. 
     
     
         33 . A secondary containment system as claimed in  claim 1 , wherein the endless wall comprises inner and outer skins and a cavity defined between the skins, wherein a plurality of reinforcing ribs extend across the cavity between the skins. 
     
     
         34 - 56 . (canceled) 
     
     
         57 . A secondary containment system for containing a substance released from a primary vessel, the secondary containment system comprising:
 a bund, the bund including a base panel having a central area and a peripheral area; and an endless wall extending from the peripheral area of the base panel and surrounding the base panel thereby defining an enclosure, the endless wall having an inner face facing the central area of the base panel and an outer face facing away from the central area of the base panel;   wherein the endless wall and the base panel are joined continuously and hermetically;   wherein the endless wall and the base panel are manufactured from a first material, the first material being liquid impermeable;   wherein an opening is formed in the central area of the base panel, the opening being sized and shaped so as to encompass a base portion of a primary vessel when the bund is assembled;   wherein the base panel comprises two or more component parts, each component part comprising an inner edge which defines a portion of the central opening, an outer portion remote the inner edge and a pair of opposing side edges connecting the inner edge and the outer portion;   wherein the component parts of the base panel are fixedly joined on assembly by joining the side edges of adjacent component parts, whereby the inner edges of the assembled component parts define the central opening, whereby the outer portions of the individual component parts define the peripheral area of the base panel and wherein seams defined between the adjacent side edges of component parts are hermetically sealed;   wherein the endless wall comprises two or more component parts, each component part comprising a free edge remote the base panel, a lower portion remote the free edge and a pair of opposing side edges connecting the free edge and the lower portion;   wherein the component parts of the endless wall are joined on assembly by fixedly joining the side edges of adjacent component parts, so that the endless wall surrounds the base panel, and wherein seams defined between the adjacent side edges of component parts are hermetically sealed; and   wherein a sealing arrangement is provided for forming upon assembly of the secondary containment system a hermetic seal between the inner edges of the base panel and a substrate surface on which the bund is to be installed, the substrate surface being also the support surface for the primary vessel;   wherein, a cover member is provided comprising at least one side wall covering the inner face of the endless wall and a cap portion covering the free edge of the endless wall, the cover member being made from a second material, the second material being fire-proof;   wherein upon installation of the bund, the substrate surface remains exposed through the central opening and a continuous surface is formed by an upwardly facing surface of the base panel and by the substrate surface exposed through the central opening; and   wherein the substrate surface is liquid-impermeable, so that when the bund is assembled, the base panel which is sealingly fastened to the substrate surface and the substrate surface exposed through the central opening of the base panel form a continuous hermetic base of the bund of the secondary containment system.