Tank lining

Abstract

An underground storage tank is lined in situ by first clearing the inner surface of the tank using water jetting. The surface is then inspected and grit blasted. A corrosion barrier coating in the form of glass flakeepoxy resin is applied to a minimum dry film thickness of 1000 microns. An adhesive is applied to the barrier coating and sheets of an HDPE interstitial grid are bonded to the adhesive forming an air gap of about 5 mm. A pliable glass reinforced plastic layer is laid upon the grid. The GRP material is exposed to UV lamps to form an impermeable shell within the tank. A surface coating layer may be applied. A leak detector is installed in the interstitial space defined by the grid.

1 . A method of lining a storage tank comprising the steps of: 
 providing a keying means on an inner surface of the tank;    applying a corrosion barrier coating to the keying means; applying an interstitial grid to the corrosion barrier coating;    providing a pliable glass reinforced material in sheet form, the class reinforced material comprising a pliable matrix of a resin, glass reinforcement inert fillers and a photo-initiator sandwiched between a backing film and a facing film;    removing the backing film from the sheet of glass reinforced material;    laying up the sheet of glass reinforced material onto the grid;    removing the facing film; and    exposing the matrix of glass reinforced plastics material to ultra violet rays to cure the glass reinforced material and form a hardened inner liner shell for the tank.    
   
   
       2 - 33 . (canceled)  
   
   
       34 . The method as claimed in  claim 1 , wherein the interstitial grid is provided by pre-formed sheets of flexible material.  
   
   
       35 . The method as claimed in  claim 1 , wherein the grid is adhesively bonded to the corrosion barrier coating.  
   
   
       36 . The method as claimed in  claim 1 , wherein the grid has a facing material applied to receive the glass reinforced plastics material.  
   
   
       37 . The method as claimed in  claim 36 , wherein the facing is a polyester mat bonded to one side of the grid.  
   
   
       38 . The method as claimed in  claim 1 , wherein at least a portion of the grid is of a plastics material.  
   
   
       39 . The method as claimed in  claim 1 , wherein at least a portion of the grid is of a composite material.  
   
   
       40 . The method as claimed in  claim 1 , wherein at least a portion of the grid is of a mesh material.  
   
   
       41 . The method as claimed in  claim 40 , wherein the mesh is a metal mesh.  
   
   
       42 . The method as claimed in  claim 41 , wherein the mesh is an aluminium mesh.  
   
   
       43 . The method as claimed in  claim 38 , wherein the grid is high density polyethylene material.  
   
   
       44 . The method as claimed in  claim 1 , wherein, for lining, the tank is divided into a number of zones, which are separately lined.  
   
   
       45 . The method as claimed in  claim 44 , wherein the final zone to be lined is adjacent a manway into the tank.  
   
   
       45 . The method as claimed in  claim 1 , wherein the sheets of pliable glass reinforced plastics material applied to the grid in sections, the marginal edges of the sections being butt jointed.  
   
   
       46 . The method as claimed in  claim 46 , wherein the joints between adjacent sheets are covered with a glass reinforced plastics tape.  
   
   
       47 . The method as claimed in  claim 1 , including the step of: 
 applying a coating to the hardened GRP liner.    
   
   
       48 . The method as claimed in  claim 1 , wherein the keying means is provided by grit blasting the inner surface of the tank.  
   
   
       49 . The method as claimed in  claim 1 , including the step of: 
 cleaning the inner surface of the tank prior to providing the keying means.    
   
   
       50 . The method as claimed in  claim 50 , wherein the inner surface is cleaned by water jet cleaning.  
   
   
       51 . The method as claimed in  claim 1 , wherein the corrosion barrier is a glassflake epoxy resin.  
   
   
       52 . The method as claimed in  claim 52 , wherein the corrosion barrier layer is applied to a dry film thickness of greater than 1000 microns.  
   
   
       53 . The method as claimed in  claim 1 , including the steps, prior to application of a corrosion layer of: 
 inspecting the internal wall of the tank; and    repairing any imperfections in the tank wall.    
   
   
       54 . The method as claimed in  claim 1 , wherein the glass reinforced plastics is exposed to UV by directing UV lamps at the glass reinforced plastics layer.  
   
   
       55 . The method as claimed in  claim 1 , wherein the tank is an underground liquid storage tank.