GB2255382A - Fill-pipe removing method and apparatus - Google Patents

Abstract

A tool assembly for removing a fill-pipe 19 for example from an underground petrol-storage tank without removing the tank lid 11 (Figure 4) has an elongate member (30, 31, 38), 41 (Figure 2) provided with a pair of spaced radially-expandable seals (36), 39. A tubular cutter fits over the elongate member (30, 31, 38), 41 and is configured on rotation firstly to cut through a nipple 15 fitted into a tank-lid sleeve 13, and then to cut through the wall of the fill-pipe 19. Swarf cut from the nipple and fill-pipe will be retained within the fill-pipe 19 above the upper seal 39, and once cutting has been completed, the fill pipe may be withdrawn from the tank through the sleeve 13 and nipple 15, by raising the elongate member whilst still sealed to and gripping the fill-pipe. Two different tubular cutting tools may be provided, respectively for cutting through the nipple 15 and through the fill-pipe 19. <IMAGE>

Description

FILL-PIPE REMOVING METHOD AND APPARATUS This invention relates to a method of and apparatus for removing a fill-pipe from a tank having a fill-pipe assembly of the kind which will hereinafter be defined. The invention finds particular - but not exclusive - application to the removal of a fill-pipe from a tank containing flammable and volatile liquids, such as petrol.

A common form of petrol tank comprises a steel (but sometimes reinforced plastics) vessel buried below ground level and having an upstanding neck provided at the upper end thereof, with an outwardly directed flange. The tank is closed by means of a lid which fits over the neck opening, and is bolted to the flange in a liquid and gas-tight manner. Pipes for filling and drawing liquid from the tank, along with other services such as a level indicator, pass through the lid and are connected to appropriate pipework and so on within a chamber in the ground above the lid, which chamber is conventionally closed by a manhole cover.

In one very common kind of arrangement for the fill-pipe, the tank lid is made of steel and has a circular opening therethrough in which is welded a steel sleeve having internal threads. The fill-pipe itself has a smaller external diameter than the internal diameter of the sleeve, and is welded to an externally-threaded nipple which is interengaged with the threads of the sleeve. Above the lid, there is provided an upper nipple having external threads at both ends, the upper nipple being threaded into the lid sleeve. Such an assembly for a fill-pipe as has just been described will hereinafter be referred to as a "fill-pipe assembly as defined herein".

In the case of a below-ground tank fitted with a fill-pipe assembly as defined herein, it is conventional for a Tee-piece to be fitted to the upper nipple, a pipe being threaded to the side branch of the Tee-piece, which pipe thus extends laterally of the below-ground chamber. A joint is provided in this pipe beyond the edge of the tank lid, whereby the tank lid may be removed from the tank and lifted out of the chamber once said joint has been disconnected, provided that all other connections to the lid also are disconnected. In such an assembly, the upper arm of the tank Tee-piece is closed off with á simpl-e male- threaded plug.

In the case of a below-ground garage forecourt tank intended to hold petrol, the opening of the tank by removing the tank lid has to be performed with great caution and special measures have to he taken in order to avoid the risk of fire and explosion. Generally speaking, this may be performed only once appropriate notice has been given to the local Government Authority, and then the tank must be emptied of all petrol, whereafter the tank is filled with water to displace all petrol fumes and vapours. The joint in the transverse pipe from the Tee-piece has to be disconnected, along with all other pipes and services from the lid, and then the ring of bolts around the lid are removed. Once done, the tank lid may be lifted together with the fill-pipe projecting downwardly below the lid.When the required servicing - whatever that might be - has been completed, the fill-pipe together with the lid are re-fitted to the tank, and then the tank has to be subjected to a pressure test, in order to ensure that a perfect seal is formed between the tank lid and the neck flange. Once tested, the various pipes and other connections are re-made to the tank lid, and then the tank has to be completely drained of water, before it can be placed back in service. Also, the water will be contaminated and so has to be disposed of with considerable care. It will be appreciated that the above procedures take a most considerable time and may be performed only by skilled personnel; a tank typically is out of service for 3 to 5 days if the lid has to be removed, for any reason.

In the past, it has only very rarely been necessary to open a tank by removing its lid, once installation has been completed. However, both on safety grounds and for environmental reasons, in many areas it is now a requirement to fit an automatic valve to the fill-pipe of a tank having a fill assembly as defined herein, to prevent the tank being over-filled with petrol or other noxious liquid. This may be achieved only by removing the fill-pipe from the threaded sleeve of the tank lid, and replacing that fill-pipe by another having an anti-over-fill valve located therein. In turn, this necessitates opening the tank by removing its lid, and all that that entails, as described above.Thus, the cost of fitting such an anti-over-fill valve in an existing below ground petrol tank in a garage forecourt is very high, and moreover often gives rise to loss of sales for the period that the tank is out of service.

The present invention aims at providing both a method of and apparatus for removing a fill-pipe from a tank fill-pipe assembly as defined herein, which method is both fast and relatively easy to operate and obviates the need to remove the tank lid.

According to one aspect of the present invention, there is provided a method of removing a fill-pipe from a tank fill-pipe assembly as defined herein, comprising the steps of: inserting an elongate member having a radiallyexpandable plug at or adjacent its lower end into the fill-pipe from the nipple side of said assembly; expanding radially said plug until the plug grips the internal wall of the fill-pipe; passing a tubular cutting tool having cutting teeth at its lower end over said elongate member, the cutting tool being adapted on rotation to form a bore through said assembly, the diameter of which bore is greater than the external diameter of the fill-pipe; rotating the cutting tool to form a bore as aforesaid until the fill-pipe is cut free of said assembly; and drawing the elongate member upwardly through the bored assembly, and so also drawing the gripped fillpipe upwardly through the bored assembly and clear thereof.

It will be appreciated that by using the method of the present invention, it is possible to remove the fill-pipe from a tank fill-pipe assembly as defined herein without the need to open the tank by removing its lid. Indeed, for certain preferred removing methods of this invention, it is possible to remove the fill-pipe without the need to take the tank out of service, and so without the need to drain the tank and then re-fill it with water. Clearly, this has great advantages from the economic point of view, without in any way prejudicing the safety of the tank installation.

Once the manhole cover to the underground chamber has been removed, all that is necessary is for the plug to be unthreaded to the tank Tee-piece, so giving vertical access to the fill-pipe assembly as defined herein for said elongate member and for the cutting tool. All cutting swarf (except for perhaps a few particles at the moment boring is completed, as the fill-pipe is separated from its nipple) will be retained within the cutting tool or within the fillpipe above the expanded expandable plug, and so will be withdrawn with the fill-pipe.

In a preferred method of this invention, the step of expanding the plug is performed also to effect a seal against the internal wall of the fill-pipe.

Depending upon the length of the elongate member and the depth to which the tank is filled when the method is performed, it is possible that the seal with the fill-pipe will be perfected above the liquid level in the tank, so completely isolating the liquid in the tank from the boring of the fill-pipe assembly. This however may be assured by providing a second radiallyexpandable plug on the elongate member, which second plug is spaced from said first-mentioned plug, the two plugs serving simultaneously both to grip and effect seals against the internal wall of the fill-pipe prior to the commencement of boring.

Advantageously, there is a leakage path past the lower radially-expandable plug, whereby liquid trapped in the fill-pipe above the lower plug may drain past that plug back into the tank as the fill-pipe is withdrawn, following the completion of boring.

Preferably, two cutting tools are used to form said bore through the fill-pipe assembly, the first cutting tool being adapted to bore the upper nipple connecting the tank Tee-piece to the tank sleeve, and the second cutting tool being adapted to cut the wall of the fill-pipe until the fill-pipe comes clear of its associated nipple. By providing two cutting tools in this way, each may be specifically adapted for the cutting function it is required to perform - that is to say, the first cutting tool is adapted to bore the upper nipple (which typically is of cast iron or steel), and the second cutting tool is adapted to cut both the fill-pipe and to bore its associated nipple, both of which are typically of an aluminium alloy.

After performing the method, a different design of fill-pipe may be fitted to the tank lid, which fillpipe may nevertheless have the same external diameter as the original fill-pipe now removed. Such a replacement fill-pipe may have an outwardly-directed flange at its upper end, which flange may bear on the upper rim of the upper nipple threaded into the tank lid sleeve, a cage then being fitted within the tank Tee-piece to bear on the flange of the fill-pipe which cage is clamped in position on replacement of the plug into the upper arm of the Tee-piece. However, by virtue of the open nature of the cage, fluid may flow from the transverse pipe into the tank Tee-piece, and so into the replacement fill-pipe.

According to a second aspect of the present invention, there is provided a tool assembly for removing a fill-pipe from a tank fill-pipe assembly as defined herein, which tool assembly comprises: an elongate member having a radially expandable plug at or adjacent one end; means to effect radial expansion of the plug internally to grip a fill-pipe when the tool assembly has been inserted from above into a fill-pipe assembly as defined herein; and a tubular cutting tool adapted to be rotatable about said elongate member and arranged to cut a bore through said assembly the diameter of which bore is at least as great as the external diameter of the fillpipe to be removed.

It will be appreciated that the tool assembly as just defined is used in performing the method of this invention as defined herein before.

Preferably the tubular cutting tool has a ring of cutting teeth arranged on a cutter body, there being a guide ring projecting forwardly in front of the cutting teeth which guide ring is a rotatable fit within the component to be bored by the cutting tool, so as thereby to centre and guide the cutting teeth. The guide ring may be formed separately from the cutter body, in which case it may be screw-threaded into the forward end of the cutter body. In practice, two guide rings are normally required, one for cutting through the upper nipple and the other for cutting the fillpipe and its associated nipple.However, since the upper nipple and the fill-pipe and its associated nipple are normally made of different materials, it is most preferred for there to be provided separate tubular cutting tools, each having an appropriate guide ring, and each specifically adapted for the component to be bored thereby.

Each guide ring preferably defines an internal bore which is a running fit on the elongate member carrying the radially-expandable plug; in this case, the elongate member itself should be circular whereby the guide ring may properly locate thereon.

The cutter body may have internal threads at its rear end, engaged with external threads on a hollow drive bar, which drive bar is a running fit on the elongate member. Such a drive bar may be adapted to be turned from its upper end or from part way along its length, to effect cutting rotation of the cutting tool, the length of the drive bar being such that when the cutting tool is cutting the tank fill-pipe assembly, following the fitting of the elongate member thereto, the end of the elongate member remote from the radially-expandable plug projects beyond the end of the drive bar remote from its cutting tool.

The radially expandable plug preferably comprises a resiliently deformable annulus, and the means to effect radial expansion thereof is arranged axially to compress the annulus. In this case, the elongate member may comprise an elongate inner member having a flange at or adjacent one end, which flange supports one face of the resiliently deformable annulus, an elongate outer member being fitted over the inner member and engaging the opposed face of the annulus, and the expansion means comprising screw-threaded means acting between the inner and outer members and arranged to drive the outer member towards the flange of the inner member, thereby axially to compress the annulus.

For the arrangement just-described, the outer member may comprise separate upper and lower parts, a second radially expandable plug being disposed between said parts whereby the second radially expandable plug will be compressed axially simultaneously with the axial compression of the first-mentioned radially expandable plug, on operation of the expansion means.

In a preferred cutting tool of this invention, the expansion means comprises inter-engaged first and second screw-threaded tubes arranged to fit over the inner member so that one of the tubes bears on the upper part of the outer member and the other of the tubes is locked to the inner member, whereby relative rotation between the tubes will drive the outer member axially respectively with the inner member, and so compress the (or each) radially expandable plug.

One specific example of a method of this invention and a specific embodiment of a tool also of this invention will now be described for the purposes of illustration, reference being made to the accompanying drawings, in which: Figure 1 is a vertical sectional view through a typical example of fill-pipe assembly as described herein; Figure 2 is an exploded view of the components making up an embodiment of an elongate member assembly used in a method of this invention; Figure 3A is an exploded view of a cutting tool used in with the elongate member assembly; Figure 3B is a drive bar for the cutting tool of Figure 3A; and Figure 4 is a diagrammatic view showing performance of an example of a method of the invention to remove a fill-pipe from a fill-pipe assembly as illustrated in Figure 1.

Referring initially to Figure 1, there is shown an example of a fill-pipe assembly 10 as described herein, as applied to a lid 11 for a flanged neck (not shown) of a below-ground forecourt petrol tank (also not shown). The lid 11 is of steel and has a ring of peripheral holes 12 which may register with corresponding holes in the flange of the tank neck and through which holes bolts may be passed to clamp the lid 11 to that flange, a suitable sealing compound being disposed between the lid and the flange so as thereby to effect a liquid and gas-type seal. A circular opening is formed through the lid 11, in which is welded a steel sleeve 13 having internal threads formed in each end portion thereof. Threaded into the upper end portion of the lid sleeve 13 is a cast iron upper nipple 14 having a driving flange 15 disposed between its externally threaded end portions 16 and 17.

A tank Tee-piece 18, having internal threads in each branch, is threaded on to the upper nipple 14, with its principal axis co-axial with the nipple 14.

A fill-pipe 19, typically of an aluminium alloy,is welded into an externally threaded nipple 20, also of aluminium alloy, the external threads 21 of the nipple 20 being engaged with the lower end portion of the lid sleeve 13, below the tank lid 11. The fill-pipe 19 extends almost to the bottom of the tank.

When the fill-pipe assembly as described above is in use, an externally threaded plug (not-shown) is fitted into the upper threads 22 of the Tee-piece 18, to close off that arm of the Tee-piece, and a transversely-extending pipe (not shown) is threaded into the side arm 23 of the Tee-piece, that transversely-extending pipe leading to a fill-union for the tank.

It will be appreciated that in order to remove the fill-pipe 19 from the assembly described above, it is necessary to remove the tank lid 11, in order that the fill-pipe nipple 20 may be unthreaded from the lid sleeve 13. However, by the method of this invention, the fill-pipe 19 may be removed without the need also to remove the tank lid from the tank.

The method of the invention is performed using a tool including an elongate member assembly as illustrated in Figure 2. This member comprises a twopart inner main support tube in two parts 30 and 31 which parts are ordinarily locked together by a coupling 32, including a transverse locking pin (not shown). Part 30 is closed by a plate (not shown) welded across its lower end, and part 31 has secured to its upper end 33 a suspension eye 34. Part 30 carries adjacent its lower end an external flange 35, on which is supported a resiliently deformable annulus 36 (for example of a synthetic oil- and petrol-proof elastomeric material) bonded between two washers 37.

A tubular spacer 38 fits over the inner support tube and has a smaller external diameter than the relaxed outer diameter of the annulus 36. A further annulus 39 similar to annulus 36 and also bonded between two washers 40 rests on the upper end of the spacer 38. An upper guide tube 41 fits over part 31 of the support tube, and has a thrust washer 42 bearing against its upper face.

A clamping unit comprising tube 43 having external threads at its lower end and a further tube 44 having internal threads at its upper end is fitted over the upper part 31 of the support tube, with tube 44 bearing on the thrust washer 42. Tube 43 is secured to upper part 31 by means of a pin 45, extending transversely through registering holes 46 and 47 in tube 43 and part 31 respectively.

It will be appreciated that when the inner member of the assembly has been fully assembled, rotating the tube 44 relative to tube 43 (which is locked to part 31) will move tube 44 axially; provided tube 44 is rotated in the correct sense, this will drive upper guide tube 41 towards flange 35, so compressing axially the annuli 39 and 36, which thus causes those annuli to expand radially outwardly.

The inner tube assembly described above with reference to Figure 2 is used in conjunction with a cutting tool and drive bar, illustrated in Figures 3A and 3B respectively. The cutting tool (Figure 3A) comprises a tubular body 50 having internal threads 51 and 52 and a plurality of tool steel cutting teeth 53 brazed or otherwise secured in slots milled into the outer surface of the body 50, from the forward end 54 thereof. A guide ring 55 is threaded into threads 51 at the forward end 54 of the cutting tool, the guide ring having a flange 56 the external diameter of which is a running fit within the component to be cut by the teeth 53; the teeth 53 consequently project radially beyond the flange 56. The guide ring 55 has swarf relief holes 57, permitting material cut by the teeth 53 to pass to the interior of the cutting tool.

Figure 3B shows a drive bar 60 for the cutting tool, which drive bar is tubular and has an internal diameter arranged to be a running fit on the upper guide tube 41. The forward end 61 of the drive bar has threads 62 interengageable with threads 52 of the tubular body 50, the drive bar 60 and tubular body 50 having tommy-bar holes 63 and 64 respectively to facilitate tightening and loosening of the cutting tool. End 65 of the bar 60 is appropriately configured to permit the coupling thereto of a rotary drive mechanism (not shown).

The apparatus described above is used to perform a method of this invention to remove fill-pipe 19 from the assembly of Figure 1 in the following manner. The manhole cover above the fill-pipe assembly is removed, and then the plug closing the upper arm of the tank Tee-piece is removed from threads 22. A rotary drilling rig, conveniently in the form of a towable trailer which may be up-ended over the manhole, is suitably positioned with its drive axis co-axial with the fill-pipe assembly axis, and the elongate member assembly of Figure 2 together with a cutting tool and drive bar 60 is suspended from the rig by eye 34, for lowering through the tank Tee-piece until the upper guide tube 41 is disposed within the tank Tee-piece 18 and the fill-pipe nipple 20.Then, tube 44 is rotated radially to expand both annuli 36 and 39, whereby those annuli grip and effect a seal against the inner wall of the fill-pipe 19.

The cutting tool as shown in Figure 3A and having suitably shaped cutting teeth 53 together with a guide ring 55 of a suitable diameter and mounted on the drive bar 60 is lowered over the upper guide tube 41 until the flange 56 enters the upper nipple 14 and the cutting teeth 53 are ready to commence boring of that upper nipple. The drive bar 60 is at this point rotated, so that boring of the upper nipple may commence. Figure 4 illustrates boring of the upper nipple, when part-completed.

When boring of the upper nipple has fully been completed, the drive bar 60 is withdrawn with its cutting tool and is replaced by a second bar and cutting tool, specifically adapted to bore the fillpipe 19 and its nipple 20 to a diameter slightly greater than the external diameter of the fill-pipe 19.

The replacement bar and cutting tool are then lowered over the upper guide tube 41, through the bored upper nipple, and boring is recommenced when the cutter teeth engage the top face of the fill-pipe nipple 20. To prevent the nipple 20 unscrewing from the sleeve 13, the bar is rotated counter-clockwise (from above) and a left-hand thread connects the bar to its cutting tool.

Boring is continued until the cutter teeth come clear of the weld-bead at the lower end of the fill-pipe nipple 20; at this point, the fill-pipe 19 is free of the assembly but is securely held by the expanded annuli 36 and 39.

It will be appreciated that during both cutting operations, all swarf collects within the fill-pipe 19, above the seal effected by the upper annulus 39, though there is a possibility that an insignificant amount of swarf might fall into the tank at the moment the weld bead of the fill-pipe nipple 20 is cut through.

Remov-I~of the fill-pipe 19 is completed by raising the inner assembly by lifting the eye 34, whilst the annuli remain expanded to grip the fill-pipe 19. The rig should have a sufficient lifting height to enable at least the greater part of the fill-pipe 19 to be lifted clear of the fill-pipe assembly. Though not shown in the drawings, a leakage path may be provided past the lower annulus 36, so that any petrol trapped between the annuli 39 and 36 may drain on lifting the fill-pipe. Such a leakage path also will prevent pressure build up between the annuli, should for example the temperature rise during the cutting operation.

Claims (21)

1. A method of removing a fill-pipe from a tank fillpipe assembly as defined herein, comprising the steps of: inserting an elongate member having a radiallyexpandable plug at or adjacent its lower end into the fill-pipe from the nipple side of said assembly; expanding radially said plug until the plug grips the internal wall of the fill-pipe; passing a tubular cutting tool having cutting teeth at its lower end over said elongate member, the cutting tool being adapted on rotation to form a bore through said assembly, the diameter of which bore is greater than the external diameter of the fill-pipe; rotating the cutting tool to form a bore as aforesaid until the fill-pipe is cut free of said assembly; and drawing the elongate member upwardly through the bored assembly, and so also drawing the gripped fillpipe upwardly through the bored assembly and clear thereof.

2. A method according to Claim 1, wherein the expanding of the plug to grip the fill pipe also effects a seal against the internal wall of the fillpipe.

3. A method according to Claim 1 or Claim 2, wherein the elongate member has a second radially-expandable plug spaced along the member from the first-mentioned plug, and said second plug is expanded to grip and effect a seal against the internal wall pf the fillpipe following insertion of the elongate member into the fill-pipe but prior to the commencement of boring.

4. A method according to any of the preceding Claims, wherein the first-mentioned plug is configured to provide a liquid leakage path whereby liquid trapped in the fill-pipe above that plug may drain past that plug back into the tank as the fill-pipe is withdrawn, following the completion of boring.

5. A method according to any of the preceding claims, wherein two cutting tools are used to form said bore through the fill-pipe assembly, the first cutting tool being adapted to bore the upper nipple connecting the tank Tee-piece to the tank sleeve, and the second cutting tool being adapted to cut the wall of the fillpipe until the fill-pipe comes clear of its associated nipple.

6. A method according to any of the preceding claims, and including the further step of fitting another fillpipe to the tank lid, which fill-pipe has substantially the same external diameter as the removed original fill-pipe.

7. A method according to Claim 6, wherein said another fill-pipe is lowered through the tank lid sleeve until an outwardly-directed flange at the upper end of said another fill-pipe bears on the upper rim of the upper rim of the upper nipple threaded into the tank lid-sleeve, whereafter a cage is fitted within the tank Tee-piece to bear on the flange of the fill-pipe, and then the cage is clamped in position on replacement of a stop-plug into the upper arm of the Tee-piece.

8. A method of removing a fill pipe from a tank fillpipe assembly as defined herein, and substantially as hereinbefore described with reference to the accompanying drawings.

9. A method according to Claim 8, and including the further step of replacing the removed fill-pipe by another fill-pipe, which further step is performed substantially as described hereinbefore with reference to the accompanying drawings.

10. A tool assembly for removing a fill-pipe from a tank fill-pipe assembly as defined herein, which tool assembly comprises: an elongate member having a radially expandable plug at or adjacent one end; means to effect radial expansion of the plug internally to grip a fill-pipe when the tool assembly has been inserted from above into a fill-pipe assembly as defined herein; and a tubular cutting tool adapted to be rotatable about said elongate member and arranged to cut a bore through said assembly the diameter of which bore is at least as great as the external diameter of the fillpipe to be removed.

11. A tool assembly according to Claim 10! wherein the tubular cutting tool has a ring of cutting teeth arranged on a cutter body, there being a guide ring projecting forwardly in front of the cutting teeth which guide ring is a rotatable fit within the component to be bored by the cutting tool, so as thereby to centre and guide the cutting teeth.

12. A tool assembly according to Claim 11, wherein the guide ring is formed separately from but is screwthreaded into the cutter body.

13. A tool assembly according to Claim 12, wherein there are provided two guide rings selectively connectable to the cutter body, one guide ring being configured for cutting through the upper nipple and the other for cutting the fill-pipe and its associated nipple.

14. A tool assembly according to Claim 10 or Claim 11, wherein there are provided two separate tubular cutting tools each having an appropriate guide ring, each cutting tool being specifically adapted for the component to be bored thereby.

15. A tool assembly according to any of Claims 10 to 14, wherein the or each guide ring defines an internal bore which is a running fit on the elongate member carrying the radially-expandable plug.

16. A tool assembly according to any of Claims 10 to 15, wherein the cutter body has internal threads at its rear end, which threads are engaged with external threads on a hollow drive bar, the drive bar being a running fit on the elongate member.

17. A tool assembly according to any of claims 10 to 16, wherein the radially expandable plug comprises a resiliently deformable annulus, there being means axially to compress the annulus thereby to effect radial expansion thereof.

18. A tool assembly according to Claim 17, wherein the elongate member comprises an elongate inner member having a flange at or adjacent one end which flange supports one face of the resiliently deformable annulus, an elongate outer member fitted over the inner member and engaging the opposed face of the annulus, and the expansion means comprising screw-threaded means acting between the inner and outer members and arranged to drive the outer member towards the flange of the inner member, thereby axially to compress the annulus.

19. A tool assembly according to Claim 18, wherein the outer member comprises separate upper and lower parts, a second radially expandable plug being disposed between said parts whereby the second radially expandable plug will be compressed axially simultaneously with the axial compression of the first mentioned radially expandable plug, on operation of the expansion means.

20. A tool assembly according to Claim 18 or Claim 19, wherein the expansion means comprises inter-engaged first and second screw-threaded tubes arranged to fit over the inner member so that one of the tubes bears on the upper part of the outer member and the other of the tubes is locked to the inner member, whereby relative rotation between the tubes will drive the outer member axially with respect to the inner member, and so compress the (or each) radially expandable plug.

21. A tool assembly for removing a fill-pipe from a tank fill-pipe assembly as defined herein, and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.