AU2004201688B2 - Access fitting for tank - Google Patents

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "ACCESS FITTING FOR TANK" The following statement is a full description of this invention, including the best method of performing it known to me/us: 2 "ACCESS FITTING FOR TANK" This invention relates to an access fitting forwater tanks, reservoirs or other containers adapted to contain liquids such as water, liquid chemicals and molasses. 5 A conventional access fitting or outlet fitting for tanks is shown in Australian Registered Design 130338 and this comprises a screw threaded shank having a flange at one end of hexagonal shape and a pair of lugs extending outwardly from the flange. The screw threaded shank included a left hand threaded portion proximal to the flange and a right hand threaded 10 portion distal to the flange. In practice this access fitting was inserted through a hole cut in a side wall or base wall of a tank and functioned to allow water inside the tank to be used as a water source for a variety of applications such as irrigation, watering crops, a source of drinking water and the like. Usually an external 15 fitting such as a valve assembly or external conduit was screw threadedly attached to the right handed threaded portion. Also an internal fitting such as a valve assembly or inlet conduit was screw threadedly attached to an internal screw threaded bore of the shank. When the access fitting was being installed to the tank it was 20 necessary for a person to obtain access to the tank interior and push the fitting through the hole with the shank extending outwardly from the wall of the tank. Subsequently a nut was screwed onto the left hand threaded portion of the shank which abutted the wall of the tank to fasten the access fitting to the tank. During attachment of the nut to the shank it was usually 3 necessary for the person inside the tank to use a tool to hold the hexagonally shaped flange to prevent the entire access fitting from rotating. However there were disadvantages associated with this arrangement and these mainly occurred when it was necessary to disconnect and 5 subsequently reconnect the access fitting to the tank for purposes of repair or maintenance or when it was necessary to dismantle the internal fitting or external fitting from the shank. When it was necessary to disconnect and reconnect the nut to the left hand threaded portion of the shank it was usually necessary for one person to gain access to the tank interior and use 10 a tool such as a spanner to grip the flange located internally of the tank wall to thereby allow the nut to be unscrewed from or screwed onto the shank similar to the installation procedure described above. Therefore this operation as well as the installation procedure could only be carried out by two persons with one person being outside the tank and the other person 15 being inside the tank. If this operation did not occur often the entire access fitting rotated when the nut was being disconnected or re-connected to the shank. In additional this operation could only be carried out when the tank was empty and thus it was time consuming and costly to carry out this operation because the tank had to be firstly drained of water. Also if the nut 20 was over tightened or over tensioned when being re-connected after disconnection this may cause damage to the access fitting such as the thread being stripped or damaged. As a consequence a seal assembly, which was often installed with the access fitting was often damaged when over tensioning of the nut occurred. Usually the seal assembly which was a 4 circular rubber disc was deformed or bowed outwardly when over tensioning occurred. It will also be appreciated that the above disadvantages were exacerbated when the tank was located on a farm or agricultural property 5 which was at a remote location and thus a new or replacement fitting had to be obtained from the nearest town or city. It is therefore an object of the invention to provide an access fitting for a tank which may alleviate the aforementioned disadvantages of the prior art. 10 The invention provided therefore an access fitting for a tank having an access fitting for a tank having a head flange constituting an innerend of the access fitting and a hollow shank extending from the head flange which shank has a proximal external screw threaded portion adjacent the flange and an external unthreaded portion which in use (i) may be engaged by a 15 tool to prevent rotation of the shank and (ii) said head flange is located adjacent an inner surface of the tank and sealingly engages said inner surface. The unthreaded intermediate portion may be knurled or milled so as to be provided with a suitable surface so as to be gripped by a tool such as a 20 spanner such as a shifting spanner, wrench or socket. However more preferably the unthreaded intermediate portion may be provided with a hexagonal or polygonal shape so as to be gripped by a tool having a socket or gripping part of corresponding shape. The unthreaded part may have a length between 6-25mm as may be required by the user.

5 There also may be provided a distal unthreaded portion remote from the head flange which is preferably of opposite hand to the proximal unthreaded position. The proximal threaded portion may be of left hand thread and the 5 distal portion may be of right hand thread although the reverse may be adopted if suitable in some circumstances. In some cases both the proximal portion and the distal portion may be of right hand thread and in a less preferred arrangement each of the proximal and distal portions may be of left hand thread. 10 The flange may have any suitable shape such as a circular or polygonal such as hexagonal. The access fitting of the invention may also include a nut component having an internal screw threaded passage or bore of the same hand as the proximal screw threaded portion of the shank. Usually this will be a left hand 15 thread. The nut component may comprise a disc suitably of hexagonal configuration having the abovementioned internal passage or bore. Alternatively the nut component may comprise an integral assembly of outer flange which may be of similar diameter to the flange of the outlet fitting 20 referred to above and a flange of lesser diameter which constitutes a gripping means for a spanner or other tool as shown in the preferred embodiment. The shank may also include an internal threaded bore or internal passage for connection of an internal fitting as hereinafter described and the 6 distal threaded portion may be used for attachment to an outlet fitting as hereinafter described. The outlet fitting of the invention may also comprising sealing means between the flange and an internal surface of a tank wall surrounding the 5 aperture through which the shank may extend. The sealing means may include a disc having a central aperture made of rubber or other elastomeric material or more preferably is an O-ring located in a retaining groove in a surface of the flange abutting the internal surface of the tank wall Reference may now be made to a preferred embodiment of the 10 invention as shown in the drawings wherein FIG 1 is a side view of the access fitting prior to attachment of the nut component; and FIG 2 is a similar view to FIG 1 showing the access fitting installed to the tank with the nut component attached to the shank of the outlet fitting. 15 FIG 3 is an exploded perspective view of the inlet fitting of FIGS 1-2; and FIG 4 shows the inlet fitting of FIGS 1-3 incorporating a gate valve in use. In FIGS 1-3 reference is made to access fitting 10 including a head or 20 end flange 11, shank 12 having a screw threaded left hand inner portion 13, hexagonal non threaded portion 14 and outer threaded portion 15 having a right hand thread. Non threaded portion 14 includes flats 14A separated by peripheral portions 14B. The inlet fitting 10 also includes an internal passage 16 shown by lines in phantom, and groove 17 having O-ring 18 7 located in flange 11. Internal passage 16 may, if desired, be divided into an inner threaded part 16A and an outer threaded part 16B leaving an intermediate unthreaded part 16C- alternatively, and more preferably, internal passage 16 may be screw threaded from end to end. 5 The access fitting 10 is shown in FIG 1 with flange 11 abutting internal surface 19 of peripheral wall 21 of a tank with 0-ring 18 in bearing contact with internal surface 19. Shank 12 protrudes through an aperture 20 located in tank wall 21. There is also provided an external nut component 22 having an 10 internal passage 23 indicated by lines in phantom. Internal passage 23 comprises a threaded internal socket of corresponding left hand thread to threaded portion 13 of fitting 10 so that nut component 22 may be screw threadedly attached to portion 13 as shown in FIG 2. Component 22 is provided with inner flange 24 and outer flange 25. Outer flange 25 may be 15 gripped by a spanner or other suitable tool for attaching nut component 22 to threaded portion 13. Flange 24 is shown abutting external surface 26 of wall 21 as shown in FIG. 2 and has a greater diameter than flange 25. It is also appropriate to attach an external fitting such as a pipe or valve to threaded portion 15 of shank 12 and this is indicated in FIG 2 20 wherein external fitting 27 is shown attached to threaded portion 15. It also may be appropriate to attach internal fitting 28 to internal screw threaded passage 16 and this is also shown in FIG 2. In FIG 4 reference is made to the inlet fitting 10 incorporating a gate valve assembly 29 having body 307 rotatable handle 31, and end flanges 32 8 and 33. Gate valve assembly 29 may be used to interconnect threaded portion 15 with external fitting or conduit 28 so as to regulate or control flow of liquid through access fitting 10 through internal bore 16. Rotation of handle 31 may cause gate valve assembly 29 to assume an open or closed 5 position. There is also shown access fitting 10 attached to tank 34. In operation aperture 20 is first cut in tank wall 21 and an operator can then get access internally of tank wall 21 so as to push inlet fitting 10 through aperture 20 as shown in FIG 1 with flange 17 engaging internal surface 19 and shank 12 extending externally of tank wall 21 as indicated in 10 FIGS 1-2. Then nut component 22 is screwed onto left hand thread 13 by a suitable tool such as a spanner (not shown) gripping flange 25 which may be of hexagonal shape to facilitate this with unthreaded portion 14 also being gripped by a spanner to prevent rotation of shank 12. This means that access fitting 10 is now firmly retained within tank wall 21 and thus the 15 operation of installation of access fitting 10 to tank wall 21 may be carried out by a single person in an efficient and quick operation. This is advantageous compared to the prior art wherein installation of the conventional fitting was usually carried out by two persons as discussed above. 20 It will be appreciated that external fitting 27 may be a valve such as a ball valve or gate valve. Alternatively external fitting 27 may comprise an outlet conduit or pipe, T fitting or elbow. In relation to internal fitting 28 it will also be appreciated that this may comprise a valve such as a float valve, Tee piece, elbow or inlet conduit or 9 pipe. When it is necessary to disconnect and/or reconnect external fitting 27 or internal fitting 28 to outlet fitting 10 all that is necessary is that hexagonal unthreaded portion 14 be gripped by a spanner or other suitable 5 tool to facilitate disconnection and/or reconnection of outlet fitting 27 or internal fitting 28. This means that the flange 11 is left undisturbed and the sealing integrity of flange 11 with inner surface 19 of the tank wall 21 is maintained. Consequently the access fitting 10 of the invention has greatly increased operational longevity compared to the prior art. 10 Therefore, in a second aspect of the invention, there is provided a process for installation of an access fitting having a head flange which constitutes an inner end of the access fitting and a hollow internal bore to a tank for the purpose of controlling flow of liquid into or out of the tank which includes the steps of: 15 (1) inserting the access fitting having a hollow bore through an aperture in a side wall of the tank whereby the head flange sealingly abuts an internal surface of the side wall; (ii) attaching a nut component to the access fitting wherein 20 said nut component is screw threadedly secured to the access fitting within said aperture while simultaneously; (iii) gripping the access fitting with a tool to prevent rotation of the access fitting during step (ii). In a third aspect of the invention there is provided a process of 10 disconnection of an external fitting or internal fitting to an access fitting retained in a side wall of a tank, said access fitting controlling flow of liquid into or out of said tank and having a head flange constituting an inner end of the access fitting sealingly abutting an internal surface of the side wall said 5 process including the steps of: (i) gripping the access fitting by a tool to prevent rotation thereof; and (ii) simultaneously disconnecting the external fitting or fitting from the access fitting. 10 The invention also includes within its scope a tank having the access fitting retained in an aperture of a wall thereof.

Claims (15)

1. An access fitting for a tank having a head flange constituting an inner end of the access fitting and a hollow shank extending from the head flange which shank has an external proximal screw threaded portion adjacent the 5 flange characterised in that there is provided an external unthreaded portion adjacent the proximal screw threaded portion which in use (i) may be engaged by a tool to prevent rotation of the shank and (ii) said head flange is located adjacent an inner surface of the tank and sealingly engages said inner surface. 10

2. An access fitting as claimed in claim 1 wherein the shank also has a distal screw threaded portion remote from the head flange which is of opposite hand to the proximal screw threaded portion.

3. An access fitting as claimed in claim 1 or 2 wherein the unthreaded portion has a polygonal shape so as to be gripped by a tool having a socket 15 or gripping part of corresponding shape.

4. An access fitting as claimed in claim 3 wherein the unthreaded portion is of hexagonal shape.

5. An access fitting as claimed in claims 2, 3 or 4 wherein the proximal portion is of left hand thread and the distal portion is of right hand thread. 20

6. An access fitting as claimed in any preceding claim further including a nut component having an internal screw threaded passage or bore of the same hand as the proximal portion.

7. An access fitting as claimed in claim 6 wherein the nut component has an inner flange and an outer flange of lesser diameter than the inner flange 12 which constitutes a gripping part for a spanner or other tool.

B. An access fitting as claimed in claim 7 wherein the inner flange and outer flange are integral.

9. An access fitting as claimed in claims 7 or 8 wherein the inner flange 5 has a similar diameter to the head flange.

10. An access fitting as claimed in any preceding claim wherein the hollow shank is internally screw threaded from end to end.

11. An access fitting as claimed in any preceding claim wherein the hollow shank is internally threaded at each end. 10

12. An access fitting as claimed in any preceding claim wherein the head flange has a sealing ring inserted in a mating groove in use so that said sealing ring abuts an internal surface of the tank.

13. A process for installation of an access fitting having a head flange which constitutes an inner end of the access fitting and a hollow internal 15 bore to a tank for the purpose of controlling flow of liquid into or out of the tank which includes the steps of: (i) inserting the access fitting having a hollow bore through an aperture in a side wall of the tank whereby the head flange sealingly abuts an internal surface of the side wall; 20 (ii) attaching a nut component to the access fitting wherein said nut component is screw threadedly secured to the access fitting within said aperture while simultaneously; (iii) gripping the access fitting with a tool to prevent rotation of the access fitting during step (ii). 13

14. A process of disconnection of an external fitting or internal fitting to an access fitting retained in a side wall of a tank, said access fitting controlling flow of liquid into or out of said tank and having a head flange constituting an inner end of the access fitting sealingly abutting an internal surface of the 5 side wall, said process including the steps of: (i) gripping the access fitting by a tool to prevent rotation thereof; and (ii) simultaneously disconnecting the external fitting or internal fitting from the access fitting. 10

15. A tank having an aperture in a wall thereof having retained therein an access fitting as claimed in any one of claims 1 - 11