AU2006230684A1

AU2006230684A1 - Tank outlet fitting

Info

Publication number: AU2006230684A1
Application number: AU2006230684A
Authority: AU
Inventors: Jeffrey Stephen Boyd; Craig Schilg
Original assignee: MBP AUSTRALIA Pty Ltd
Current assignee: MBP AUSTRALIA Pty Ltd
Priority date: 2005-10-24
Filing date: 2006-10-19
Publication date: 2007-05-10
Anticipated expiration: 2026-10-19
Also published as: AU2006230684B2

Description

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Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: MBP Australia Pty Ltd Actual Inventors: Craig Schilg and Jeffrey Stephen Boyd Address for Service: MADDERNS, 1st Floor, 64 Hindmarsh Square, Adelaide, South Australia, Australia Invention title: TANK OUTLET FITTING Details of Associated Provisional Application No: 2005905861 dated 24 October 2005 The following statement is a full description of this invention, including the best method of performing it known to us.

PatAU131 \O This invention relates to an improved tank outlet fitting, and more particularly a 0 0 tank outlet fitting which can be installed in the wall of the tank from the outside thereof.

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Current "bulkhead type" tank outlets generally have a fixed flange which is arranged to clamp against the inside surface of the tank by means of a clamping nut oo which threadably engages an externally threaded spigot portion on the fitting which 0 extends through a hole in the tank wall. This type of fitting needs to be installed from N the inside of the tank which means that a person is required to access the tank interior or the fitting must be fitted remotely to avoid the need to get into the tank.

Where tank entry by a person is required, the installing of the tank outlet fitting is both time consuming, and costly, and potentially dangerous.

Another problem encountered with existing tank outlet fittings is their inability to effectively seal the hole in the tank wall and thereby inhibit leakage of water from the tank. Tank outlet fittings currently available generally have a flat washer of approximately 3mm to 6mm thickness or an O-ring for sealing purposes. When installed, the washer seals on the inside surface of the tank which, in the case of moulded plastic tanks, is an uncontrolled surface in the moulding process.

Consequently the potential for leakage exists due to imperfections in the tank wall surface.

It is an object of the present invention to provide an improved tank outlet fitting which is designed so that it can be installed in the wall of a tank from outside of the tank and thereby obviates the need for a person to enter the tank to carry out its installation.

It is another object of the present invention to provide an improved tank outlet fitting which is designed to provide a reliable seal when installed in a hole in the wall of a tank, regardless of the thickness of the tank wall, it being appreciated that moulded plastic tanks can have wall thicknesses which vary quite considerably.

It is a further object of the present invention to provide an improved tank outlet 0 fitting having a sealing arrangement which renders the fitting less likely to leak regardless of the condition of the inside surface of the tank which, in the case of roto- O moulded plastic tanks, is "an uncontrolled surface" in the moulding process and imperfections can generally be found in the surface.

o00 Broadly according to this invention therefore, an outlet fitting for fitment in a hole in 0 the wall of a tank comprises: ,1a generally tubular body having oppositely directed externally threaded inner and outer spigot portions separated by an intermediate non-threaded portion which includes a frusto-conical shoulder, an adjustable flanged ring threadably engaging said inner spigot portion, said flanged ring being sized and shaped so that it is insertable through said hole in the tank wall and can then be reoriented such that portions of the flanged ring can abut against the inner surface of the tank wall at spaced locations around the hole bordering region, a clamping nut which threadably engages said outer spigot portion, and an annular seal receivable over the outer spigot portion and locatable within said hole in the tank wall, arranged and constructed so that when the inner spigot portion, along with its associated flanged ring, is inserted through the hole and the flanged ring reorientedand the seal located within the hole, tightening of the clamping nut causes the frusto-conical shoulder to be drawn into the annular seal to thereby compress annular seal between the wall of the hole and the intermediate portion of the fitting so that it forms a fluid seal therebetween.

When the fitting is initially inserted, the position of the flanged ring is threadably adjusted depending on the thickness of the tank wall where the hole is located. This will normally be done by positioning the ring so that it firmly abuts against the inner surface of the tank wall and then rotating the body of the fitting until the leading end of the frusto-conical shoulder approximately aligns with the outside edge of the hole.

NO Preferably the adjustable flanged ring has an oval or triangular shaped flange which S has a maximum width greater than the diameter of the hole in the tank wall.

O In one form of this invention, the annular seal has an integrally formed radially outstanding circular flange at its outer end, said flange, when the clamping nut is tightened, making sealing contact with the hole bordering region of the tank wall 00 outer surface.

In another form, there is provided a sealing washer received over the externally S threaded outer spigot portion and disposed between the inner face of the clamping nut and the annular seal, whereby, when the clamping nut is fully tightened, the washer makes sealing contact with the hole bordering region of the tank wall outer surface.

Preferably the externally threaded outer spigot portion includes a first right hand threaded section and a second left hand threaded section which joins to said intermediate portion, thereby enabling a standard right hand threaded fitting to be connected to the tank outlet fitting without loosening of the clamping nut.

0 Desirably, the intermediate portion includes a non-threaded inner cylindrical portion having a diameter slightly greater than the outer diameter of the externally threaded inner spigot portion and which joins to said frusto-conical shoulder.

It is a feature of the present invention that a primary seal is created between the frusto-conical shoulder formed on the intermediate portion of the main body and the perimeter surface of the hole in the tank wall, this being effected by compression of the annular seal as the frusto-conical shoulder on the main body is drawn into the seal on tightening of the clamping nut. In addition, the fitting can also have a secondary seal whereby the flange portion of the moulded seal is clamped between the clamping nut and the external surface of the tank wall. For roto- moulded plastic tanks, the external surface of the tank wall is "a controlled surface" in the moulding ID process as this surface is directly formed by the mould, and offers a sealed surface of 0 0 high integrity without the need for further dressing or adjustment.

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O It is also a feature of the present invention that the tank outlet fitting can be fitted to a variety of polyethylene tank wall thicknesses due to the ability of the flanged ring on the inner end of the body of the fitting being axially adjustable.

o00 In order to more fully explain the present invention, a preferred embodiment thereof is described hereunder in some further detail with reference to and illustrated in the 0 accompanying drawings wherein: Figures la and lb are vertical sectional views showing a tank outlet fitting respectively partly and fully installed in the wall of a tank, according to a preferred embodiment of the invention; Figure 2 is an end elevational view (looking from the inside of the tank) of the fitting shown in Figure 1; Figure 3 is an elevational view of an alternative adjustable flanged ring which can be used to clamp against the tank wall inner surface; while Figure 4 is a sectional view of an alternative sealing member for sealing off the hole in the tank wall.

'.0 Referring to Figures 1, la and 2 of the drawings, there is shown a tank outlet fitting secured in a hole 11 of a wall 12 of a tank, which, in this embodiment, is formed of plastics material by a roto-moulding process. The fitting 10 comprises a main body 13 which is formed with an inner cylindrical externally threaded spigot 15, an outer stepped cylindrical externally threaded spigot 16 and an intermediate non-threaded body portion 17. An adjustable flanged ring 18 threadably attaches to the inner externally threaded spigot 15, while a clamping nut 19 threadably attaches to an inner portion of the externally threaded outer spigot 16 and which can be tightened against the external surface 20 of the tank wall 12 with the flanged ring 18 bearing against the tank inner wall surface 21. The bordering wall region surrounding the hole 11 is thus clamped between the clamping nut 19 and the flanged ring 18 when the nut 19 is fully tightened.

IN \O O In this embodiment, the flanged ring 18 has an integrally formed oval shaped flange 18' which is shaped and sized so that it can be inserted through the hole 11 and O reoriented so that diametrically opposed flange portions thereof will abut against the tank inner wall surface 21, thereby restraining the fitting 10 against axial displacement from the hole 11.

00oO In the gap between the intermediate body portion 17 and the perimeter wall 22 of the hole 11, there is provided an annular resilient sealing member 23 which snugly slidably fits over the inner portion of the outer externally threaded spigot 16. The outer diameter of the seal 23 is approximately the same as the diameter of the hole 11 so that it can snugly fit therein. As the clamping nut 19 is tightened, the intermediate body portion 17 of the fitting is drawn into the bore of the annular seal 23 and, by virtue of a frusto-conical shoulder 24 formed on the external surface of the body portion 17, the annular wall of the seal 23 is compressed between the wall 22 of the hole 11 and the body portion 17 of the fitting 10 and provides a fluid seal therebetween. The manner in which the annular seal 23 seals against the wall of the hole 11 affords a considerable amount of tolerance so far as the diameter of the hole in the wall is concerned.

As shown in Figure 1, in this embodiment, the annular seal 23 is provided with a radially outwardly projecting flange 25 which, when the clamping nut 19 is tightened, is compressed between the clamping nut and the external surface 20 of the tank wall 12 to thereby form a secondary seal for the fitting 10. A fibre washer 26 is desirably located between the clamping nut 19 and the flange The outer spigot 16 has a large diameter cylindrical portion 28 which is formed with left hand threads for threadably engaging the clamping nut 19, and a relatively small diameter cylindrical portion 29 which is formed with external right hand threads for threadably receiving an attachment fitting such as a valve or pipe. By having the left hand and right hand threads on the outer spigot 13, an attachment fitting can be O attached to the right hand threaded portion 29 without loosening the tank outlet fitting 10 after it has been tightly secured to the wall of the tank.

o In order to install the outlet fitting 10, the main body 13 along with its flanged ring 18 Sare inserted through the hole 11 in the tank wall and the fitting orientated such that diametrically opposed end portions of the flange 18' of the ring 18 overlap opposite 00oO sides of the hole 11. The fitting is then pulled outward so that the oval-shaped flange

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18' of the ring 18 abuts against the inside surface of the tank wall. The body 13 is then rotated until the leading end of the ramped shoulder 24 is approximately Saligned with the outer edge of the hole 11. The fitting 10 is then pushed bodily into the hole 11 so that the sealing member 23 snugly locates therein. The clamping nut 19 is then tightened so that the conical shoulder 24 is drawn into the bore of the seal 23 which is thereby compressed between and sealingly engages the hole wall 22 and the shoulder 24.

It will be appreciated that compression of the seal 23 will occur once the leading end of the tapered shoulder 24 enters the bore of the seal 23, and the engagement between the surfaces of the seal 23 and the hole wall 22 and shoulder 24 provides sufficient frictional force to prevent the fitting 10 from turning while the nut 19 is 0 being tightened.

Depending of the relative diameters of the annular seal 23 and the hole 11, in some instances, there may be some initial minimal radial expansion of the seal 23 before compression occurs.

It will be appreciated that the axial position of the adjustable flanged ring 18 will vary according to the wall thickness of the tank wall 12. The greater the wall thickness of the tank wall 12, the closer the flanged ring 18 is positioned to the outer or free end of the inner spigot Referring to Figure 3 of the drawings, there is shown an alternative flanged ring which can be used in lieu of flanged ring 18. The ring 30 has triangularly shaped IN flanges 31 so that it can contact the tank inner wall surface at three equally spaced 0 O apart locations, thereby providing better stability.

,1 O Referring to Figure 4 of the drawings, there is shown an alternative annular sealing S gasket 35 to sealing member 23 shown in Figure 1. The sealing gasket 35 has a central annular enlarged seal portion 36 and an outer annular part circular sealing rib 37 00oO which, in use, seals on the outside of the tank wall 12, and hence provides a secondary seal in addition to the primary seal created by the central sealing portion 36 which seals inside the hole 11 as a result of its compression during the tightening of nut 19. The portion 36 and rib 37 are spaced apart by an annular channel or slot 38.

In another non-illustrated variation to the above described embodiment, the radial flange which is formed as an integral part of the annular seal 23 may be eliminated and replaced by a flat washer positioned between the inner face of the clamping nut 19 and the external surface 20 of the tank wall 12. As previously mentioned, the external surface of the tank wall is a controlled surface in the moulding process and hence can be formed with a sealing surface of high integrity.

Although a specific embodiment has been illustrated and described herein, it will be appreciated that many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly this application is intended to cover any such adaptation or variation of the invention described herein.

Claims

1. A water outlet fitting adapted to be installed in a hole in the wall of a tank or O like receptacle comprising: a generally tubular body having oppositely directed externally threaded inner and outer spigot portions separated by an intermediate non- 00oo threaded portion which includes a frusto-conical shoulder, said body when INO 0 the fitting is installed, extending through said hole with the spigot portions projecting to either side thereof, San adjustable flanged ring threadably engaging said inner spigot portion, said flanged ring being sized and shaped so that it can be inserted through said hole in the tank wall and reoriented such that portions of the flanged ring abut against the inner surface of the tank wall at spaced locations around the hole, a clamping nut threadably engaging said outer spigot portion, and an annular seal receivable over the outer spigot portion and locatable within said hole in the tank wall, arranged and constructed so that when said flanged ring is thus inserted and the seal located within the hole, tightening of the clamping nut causes the frusto-conical shoulder to be drawn into the annular seal which is thereby compressed between the wall of the hole and the intermediate portion of the body and forms a fluid seal therebetween.

2. An outlet fitting according to claim 1 wherein said annular seal has a central circular body portion which has an outer diameter which is the same or approximately the same as the diameter of the hole.

3. An outlet fitting according to claim 2 wherein said annular seal has an integrally formed radially projecting flange extending around the outer side of the central portion, said flange, when the clamping nut is tightened, sealingly engaging the tank wall outer surface. ID4. An outlet fitting according to claim 3 wherein said radially projecting flange 0 Sincludes an annular protruding sealing rib which, when the clamping nut is tightened, sealingly engages the tank outer wall surface. O An outlet fitting according to any one of claims 1 to 4 wherein said adjustable flanged ring has an oval shaped flange having a maximum diameter greater oo than the diameter of the hole in the tank wall.

6. An outlet fitting according to any one of claims 1 to 4 wherein said adjustable flanged ring is provided with three circumferentially spaced radially projecting triangular flanges arranged to abut the tank inner wall surface.

7. An outlet fitting according to claim 1 further comprising a sealing washer on the externally threaded outer spigot portion and disposed between the inner face of the clamping nut and said annular seal, whereby, when the clamping nut is tightened, the washer makes sealing contact with the hole bordering region of the tank wall outer surface

8. An outlet fitting according to any one of the preceding claims wherein said externally threaded outer spigot portion includes a first right hand threaded section and second left hand threaded section which joins to said intermediate portion, thereby enabling a standard right hand threaded fitting to be connected to the tank outlet fitting without loosening of the clamping nut.

9. An outlet fitting according to any one of the preceding claims wherein said intermediate portion includes an inner cylindrical portion which joins to said frusto-conical shoulder and which has a diameter greater than the outer diameter of the externally threaded inner spigot portion.

10. A water tank outlet fitting subtantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.