Improved tank collar

Abstract

A tank collar assembly comprising: —(i) a first portion adapted at a first end to be connected to a tank around a manway or to a manway itself in a substantially fluid tight manner, said first portion being adapted to extend substantially entirely around the manway on the tank and to extend away from said tank or manway such that it forms an annular flange surrounding the manway; (ii) a second portion formed from a fusible material, said second portion being attached to the first portion in a substantially fluid-tight manner by a securing means; wherein a surface of said second portion is adapted to contact a corresponding fusible mating surface on the base of an access chamber.

1 . A tank collar assembly comprising:—
 (i) a first portion adapted at a first end to be connected to a tank around a manway or to a manway itself in a substantially fluid tight manner, said first portion being adapted to extend substantially entirely around the manway on the tank and to extend away from said tank or manway such that it forms an annular flange surrounding the manway; 
 (ii) a second portion formed from a fusible material, said second portion being attached to the first portion in a substantially fluid-tight manner by a securing means; wherein a surface of said second portion is adapted to contact a corresponding fusible mating surface on the base of an access chamber. 
 
     
     
         2 . A tank collar assembly as claimed in  claim 1  wherein the first portion is formed from a metal. 
     
     
         3 . A tank collar assembly as claimed in  claim 2  wherein said securing means comprising swaging, such that a substantially fluid tight swaged joint is formed between the radially extending flange of the first portion and the second portion. 
     
     
         4 . A tank collar assembly as claimed in  claim 1  wherein the second portion is secured to the first portion by moulding the second portion to, around or within the first portion. 
     
     
         5 . A tank collar assembly as claimed in  claim 1  wherein the second portion is secured to the first portion by way of an adhesive or a sealant. 
     
     
         6 . A tank collar assembly according to  claim 1  wherein the second portion incorporates an energy transfer means adapted to heat a first surface of the second portion in order to form a substantially fluid tight seal with a mating surface of an access chamber. 
     
     
         7 . A tank collar assembly as claimed in  claim 6  wherein said energy transfer means comprises one or more electrofusion heating elements. 
     
     
         8 . A tank collar assembly as claimed in  claim 7  wherein said electrofusion heating element(s) are incorporated into the mating surface of the access chamber. 
     
     
         9 . A tank collar assembly as claimed in  claim 6  wherein the second portion rests on and is supported by the first portion in use. 
     
     
         10 . A tank collar assembly as claimed in  claim 1  wherein the assembly further comprises one or more support means, said support means being adapted to support the first portion. 
     
     
         11 . A tank collar assembly as claimed in  claim 1  and wherein the assembly is connected to the tank, wherein the first portion comprises two components, a first component connected in a substantially fluid-tight manner to the tank around the manway, and a second component is connected to the first component in a substantially fluid-tight manner, said second component extending substantially entirely around the first component in the form of a radially extending flange, the first and second components being joined during manufacture. 
     
     
         12 . A tank collar assembly as claimed in  claim 11  wherein the first component and the second component are both made of a metal. 
     
     
         13 . A tank collar assembly as claimed in  claim 12  wherein the two components are welded together. 
     
     
         14 . (canceled) 
     
     
         15 . A tank incorporating a tank collar assembly as claimed in  claim 1 . 
     
     
         16 . An access chamber incorporating a fusible surface in its base said fusible surface being adapted to mate with a corresponding fusible surface in a tank collar assembly according to  claim 1 .