Containment sump

Abstract

A containment sump which is to airtight sealingly mounted in conjunction with a collar that is mounted on a fuel tank. The containment sump, the collar and the fuel tank are all constructed to have a double walled thickness. The containment sump includes a protrusion assembly which forms a series of grooves. A vacuum is to be drawn with the coupled air gaps between the tank, the collar, containment sump and a top hat that is mounted on the containment sump with this vacuum to be conductible through all areas of the air gap which is permitted by the grooves located between the protrusions. The protrusions keep the air gap open by preventing flush abutting contact between the walls of the containment sump. A vacuum gauge is mounted in conjunction with the containment sump to read the amount of vacuum that will have been drawn within the air gap-arrangement. The vacuum gauge is located within the internal chamber which is formed interiorly of the collar, the sump and the top hat.

1 . A method of installing a containment sump on a collar of a fuel tank comprising the steps of: 
 utilizing a fuel tank which has a double wall with an air gap located between the walls of the tank and where the fuel tank has a collar mounted thereon where the collar also has an air gap and wherein the collar air gap couples with the tank air gap;    mounting an end of a double walled containment sump on said collar where said sump has an internal open ended chamber and a double wall with an air gap and where there is located a series of protrusions within said air gap in order to maintain a space between said walls of said sump and preventing the walls from assuming a flush abutting contact;    coupling said air gap of said tank with said air gap of said sump;    mounting a top hat on a free end of said sump where said top hat closes said air gap; and    installing a vacuum gauge in conjunction with said air gap; and drawing a vacuum within said air gap to a predetermined level.    
   
   
       2 . The method as defined in  claim 1  wherein the second mounting step includes: 
 utilizing a top hat that has a double wall and an air gap.    
   
   
       3 . The method as defined in  claim 1  wherein the installing step comprising: 
 mounting said vacuum gauge within the confines of an internal chamber of said top hat.