AU2011204970B2

AU2011204970B2 - A plug for plumbing

Info

Publication number: AU2011204970B2
Application number: AU2011204970A
Authority: AU
Inventors: Sydney Hawthorne
Original assignee: Plastec Australia Pty Ltd
Current assignee: Plastec Australia Pty Ltd
Priority date: 2010-07-26
Filing date: 2011-07-26
Publication date: 2015-02-19
Anticipated expiration: 2031-07-26
Also published as: AU2011204970A1

Abstract

A plug 10 for sealing a pipe end, the plug including, an elongate body 20 having a 5 first threaded end 21 for engaging a complementary screw thread formation on a pipe, a second end 22 and a bore 23 extending between the first and second ends to define a drain passage; and an end cap 40 removably mountable to the second end of the body to seal the drain passage, and which can be removed from said drain passage to permit liquid to drain there through. Figure 3

Description

A PLUG FOR PLUMBING FIELD OF THE INVENTION 5 This invention relates to a plug for plumbing. This invention relates particularly but not exclusively to a test plug for testing a plumbing installation on a building. It will therefore be convenient to hereinafter 10 describe the invention with reference to this example application. However at the same time it must be recognized that the invention is capable of broader application. BACKGROUND TO THE INVENTION 15 A plumbing installation comprises a series of interconnected pipes. Once a plumbing installation has been formed it is necessary to test the plumbing installation for leaks. This is required as part of a certification process before a plumbing system can be approved for use and before the plumbing installation 20 can be commissioned. One way to pressure test pipe work is by sealing the ends of newly installed pipes at each fitting location. Water is then pumped into the pipes under pressure into the pipe work. A pressure gauge is mounted on the pipe work to monitor the 25 pressure of liquid within the pipes. If a pipe leaks then the pressure of water will decrease and this will be reflected on the pressure gauge. If the pipe does not leak then the pressure reflected on the pressure gauge will remain substantially constant. 1 Some pipes may have a thread formed on an external surface of an end region thereof (hereinafter referred to as a male threaded pipe end). A device that is a plug for plugging this male threaded pipe end is known. The plug comprises a cylindrical body section defining a cylindrical bore having an internal surface and 5 having a screw thread formed on the internal surface of the cylindrical bore. The cylindrical bore may be sized and the screw thread may be formed so as to complement the male threaded pipe end with which it is to be engaged. 10 Other pipes may have a thread formed on an internal surface of an end region thereof (hereinafter referred to as a female threaded pipe end). A device that is a plug for plugging this female threaded pipe end is known. The plug comprises a cylindrical body section having a screw thread formed on an outer surface of the cylindrical body section. The cylindrical body section may be sized and the screw 15 thread may be formed so as to complement the female threaded pipe end with which it is to be engaged. Pipe fittings that seal male threaded pipe ends are commonly referred to as caps, whereas fittings for sealing female threaded pipe ends are commonly known as 20 plugs. In the present specification and claims, the term plug will be used to refer to any threaded fitting for sealing a threaded pipe end, regardless of the thread, unless stated otherwise. In many domestic plumbing installations such has shower, bath and basin 25 installations the end of a newly installed pipe lies within the wall cavity. After pressure testing and the test plug or cap is removed, residual water in the pipe can drip or leak into the wall cavity. This can lead to dampness in the wall cavity or even water damage which is clearly undesirable. 30 Accordingly it would be desirable if an alternative test plug could be provided for use in pressure testing a plumbing instalment. 2 SUMMARY OF THE INVENTION According to one aspect of this invention there is provided a plug for sealing a 5 pipe end, the plug including: an elongate body having a first threaded end for engaging a complementary screw thread formation on a pipe, a second end and a bore extending between the first and second ends to define a drain 10 passage;and an end cap removably mountable to the second end of the body to seal the drain passage, and which can be removed from said drain passage to permit liquid to drain there through. 15 The thread on the first end of the body that is complimentary to the screw thread of a pipe may be male or female for a female or male threaded pipe end respectively. Most commonly, pipes have male threaded ends so that the first or pipe end of the body typically has a female thread. It will be appreciated that for some applications, the thread may be a male thread for engaging a female 20 threaded pipe end. The body has a bore extending that defines a drain passage. The drain passage may be sealed with the end cap that is mountable to the body. The body and end cap may be mounted in any suitable manner, provided that when joined together 25 the drain passage is sealed against a flow of water. Typically, the means for mounting the cap to the body is by threaded engagement. A threaded projection or recess on one of the body or cap may engage a complimentary threaded recess or projection on the other of the cap or body. 3 In the embodiment in which the body has a female thread located within the bore, the test plug may include a seal within the bore so as to resist leakage of liquid from the pipe through the elongate body. 5 The plug typically includes a further seal for providing a seal between the body and the end cap. The body may have a handle or finger gripping formation formed thereon to allow a user to grip the body and rotate it relative to a pipe. Likewise, the end cap may 10 also have a handle or finger gripping portion formed thereon to allow a user to rotate the cap relative to the body. In another form of the invention, the end cap is also elongate with a first end mountable to the body and a second end, whereby the second end has a thread 15 for engaging a complimentary screw thread in a pipe. Typically, the end cap has a male threaded segment if the pipe receiving screw thread is female and the screw thread is female if the pipe end has a male thread. The reason for this is that the cap may be used to seal a pipe end in a conventional manner. An advantage of this embodiment is that if a pipe end needs to be sealed that has a thread that is 20 not complimentary to the pipe end in the body, the end cap may be used to seal the pipe. This means that a plumber does not need to carry a separate set of test caps or plugs as the case may be in addition to the plug of the invention. In use, the end cap is mounted to the body to provide an assembled plug. The 25 assembled plug is then screwed onto an end of a pipe so as to seal the pipe. When the pipe is located within a wall cavity having an access opening, the assembled plug will normally extend through the access opening. Further still the second or cap end of the body will also normally extend through the access opening in the wall. The importance of this feature will be explained below. 30 4 As discussed above, when pressure testing a pipe installation, ater all of the pipes in the plumbing installation have been sealed, the pipes are pressure tested according to conventional methods. After pressure testing, conventional test caps and plugs are removed from the pipe ends. However, contrary to such 5 conventional tests caps and plugs, with the plug of the present invention, only the end cap of the plug is initially removed so as to leave the body screwed to the pipe end. This also removes the seal to the drain passage such that residual water in the pipe can pass through the drain passage and out of the second end of the plug body. As the second end of the plug body extends through the access 10 opening, the residual water in the pipe drains from the drain passage to the outside of a wall cavity. The body may then be unscrewed from the pipe. Thus, according to a further broad form of the invention, there is provided a method of pressure testing a pipe, the method comprising the steps of: 15 providing a test plug having an elongate body having a first threaded end for engaging a complementary screw thread formation on a pipe, a second end and a bore extending between the first and second ends to define a drain passage, and 20 an end cap removably mounted to the second end to seal the drain passage; mounting the plug to the end of a pipe to be tested so as to seal the pipe end; introducing water under pressure into the sealed pipe; 25 monitoring the water pressure; turning off the water supply; removing the end cap from the body and allowing residual water in the pipe to drain from the pipe through the drain passage. 5 BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic side view of the test plug in accordance with the prior art 5 mounted over an open end of a pipe forming part of a plumbing system where the end of the pipe opens up into a wall cavity; Figure 2 is a schematic side view of the test plug and the end of a pipe shown in Figure 1 after the test plug is detached from the end of the pipe; 10 Figure 3 is an exploded upper perspective view of a test plug in accordance with one embodiment of the invention; Fig 4 is an upper perspective view of the test plug of Figure 3; 15 Figure 5 is a lower perspective view of the test plug of Figure 3; Figure 6 is a longitudinal cross sectional view of the test plug of Figure 3, Section through B-B; 20 Figure 7 is an exploded longitudinal cross sectional view of the test plug of Figure 4, Section through A-A; Figure 8 is a schematic side view of the test plug of Figure 1 mounted over an 25 open end of a pipe forming part of a plumbing system where the end of the pipe opens up into a wall cavity; and 6 Figure 9 is a schematic side view of the test plug and the pipe end of Figure 8 after an end piece of the test plug has been detached from the rest of the test plug showing water draining to the outside of the wall. 5 Figure 1 shows a schematic side view of a prior art test cap 1 mounted over an end of a pipe 2. The pipe 2 has an external or male thread and the cap 1 has a female thread. The pipe 2 is located within a wall cavity 3 behind wall 4. The wall 4 has an access hole 5 which will allow the pipe to be connected to a plumbing fixture that extends through the wall. Typical plumbing fixtures that extend through 10 a wall cavity in this way are shower or bath taps. It may be seen that the end of the pipe 2 terminates short of the access hole 5. Figure 2 is a schematic side view of the test cap 1 and pipe 2 shown in Figure 1 after pressure testing of the pipe 2 when the test cap 1 has been removed. It may 15 be seen that residual water 6 in the pipe 2 has leaked out of the end of the pipe 2 and into the wall cavity 3. Figure 3 shows an exploded view of a preferred plug 10 of the present invention. The plug 10 has a body 20 and an end cap 40. The body 20 is elongate with first 20 21 and second 22 ends. A bore, 23 which will be described in further detail below extends between the pipe 21 and plug 22 ends. In use, the bore forms a drain passage through which water can drain from a pipe after pressure testing. This will be described in further detail below. 25 The first or pipe end 21 has an internally threaded or female portion 24 (shown in Figure 6) that in use can be screwed onto an end of a pipe. The second or cap end 22 also has an internally threaded or female portion 25 that receives a male thread of the end of plug 30. 7 Finger gripping fins 26 extend along the length of the body 20 to allow a user to more easily grip the body 20 when screwing the body 20 onto and unscrewing from a pipe end. This will be discussed in further detail below. 5 The end cap 40 has first 41 and second 42, ends each with a male threaded segment 43, 44 extending therefrom. The first threaded segment 43 screws into the cap end 22 of the body. The threaded segment 44 on the second end 42 is for screwing into a female end of a pipe. The end cap 40 also has finger gripping fins 45 to allow a user to more easily grip the end cap 40 when screwing and 10 unscrewing the end cap 40 from the body 20 or a pipe as appropriate. Figure 4 shows the body 20 and end body and end cap joined together. Figure 6 is an exploded longitudinal cross section of the plug 10 of figure 3. This 15 figure shows the bore 23 that extends through body 20. The bore 23 has a first pipe engaging section 27 and a second cap mounting section 28. The pipe receiving section 27 terminates in thread 24 that screws onto a pipe. The cap mounting section 28 has a counterbored end 29 and an internal thread 32. The diameter of the first section 27 is greater than that of the second section 28 and a 20 shoulder 30 is defined at the junction thereof. An 0 ring 31 is located at this shoulder 30. In use, the O-ring provides a seal against an end of the pipe threadably engaged with threaded section 27. The end cap 40 has a blind bore 45 that tapers from the body 41 to the pipe 42 25 end. The bore 45 is closed at the body end 41 and open at the other end 42. Provision of the bore 45 allows the amount of material used in constructing the end plug to be minimized without comprising the strength of the walls of the end cap. This allows production costs to be reduced. 30 An 0 ring 46, 47 is located around the base of each male threaded segment 43, 44. 8 Figure 7 is a longitudinal view of the body 20 and end plug 40 when screwed together and how the 0 ring 46 is received within counterbore 29 so as to provide a seal between the body 20 and the end cap 40. 5 The purpose of the 0 ring 47 at the other end of the end plug 40 is to provide a seal when the pipe end 43 is used to seal an end of a female threaded pipe. Generally, pipe ends have male ends, however, in some cases, the pipes may have female ends. By providing this option to the end cap, the cap may be used 10 to seal either male or female pipe ends. An advantage of such an arrangement is that a plumber does not need to carry two sets of fittings. Figures 8 and 9 show the plug 10 of the invention when used to seal an end of a pipe 2 located within a wall cavity. This may be compared to the conventional end 15 cap as shown in figures 1 and 2. Figure 9 shows the plug 10 when sealing an end of a male threaded pipe 2. The end plug 40 is screwed onto the end of the body 20 so as to stop water passing through bore 23. After pressure testing of the pipe installation has been conducted, the end cap 30 is unscrewed form the body 20. It will be seen that the open end of the body 20 extends out of drain out of the 20 pipe to the outside of the wall cavity. After the water has drained from the pipe 2, the body 20 is then unscrewed from the pipe 2. It may be seen that the plug of the present invention allows a pipe end within a wall cavity to be sealed prior to pressure testing and following testing, removed in 25 such a way so as to avoid or minimize water leakage into the wall cavity. This has obvious advantages in limiting water damage within the wall cavity. The plug may also have other applications such as sealing a pipe end during renovations or replacing fittings when it is desired to have the water supply turned on without all pipe fixtures being fitted. 30 9 It will of course be realized that the above has been given only by way of illustrative example of the invention and that all such modifications and variations thereto, as would be apparent to persons skilled in the art, are deemed to fall within the broad scope and ambit of the invention as is herein set forth. 5 10

Claims

1. A plug when used for sealing a pipe end of an outlet pipe that is behind an access opening within a wall cavity, the plug including: an elongate body having a first threaded end for engaging a complementary screw thread formation on a pipe, a second end, wherein the elongate body is dimensioned such that the length of the body is greater than the diameter of the pipe to which it is to be engaged, such that when the elongate body is engaged to the end of the pipe, the second end extends through the access opening of the wall cavity. a bore extending between the first and second ends to define a drain passage; and an end cap removably mountable to the second end of the body to seal the drain passage, and which can be removed from said drain passage to permit liquid to drain there through.

2. The plug of claim 1, wherein the first threaded end is an internal thread located within the bore.

3. The plug of claim 1 or claim 2, further including a finger gripping portion located on the end cap and/or body.

4. The plug of any one of claims 1 to 3, wherein the second end of the body and the end cap have complimentary threads for mounting the end cap to the body.

5. The plug of claim 4, wherein the thread on the second end of the body is an internal thread and the end cap has a male threaded segment complimentary to said internal thread 11

6. The plug of any one of claims 1 to 3, wherein the bore has a first pipe engaging section and a second cap engaging section and the diameter of the first section is greater than that of the second section and a shoulder is defined at the junction thereof.

7. The plug of any one of claims 1 to 4, wherein the end cap has a blind bore that is at the threaded end that engages the body and is open at the other end.

8. The plug of claim 5, wherein the bore is tapered towards the closed end.

9. The plug of any one of claims 1 to 6, wherein the end cap is elongate with a first end mountable to the body and a second threaded end for engaging a complementary screw thread formation on a pipe.

10. The plug of claim 9, wherein the second threaded end is a male threaded segment.

11. The plug of any one of claims 1 to 10, wherein the body includes a seal for providing a seal against a pipe engaged by the body.

12. The plug of any one of claims 1 to 11 which includes a seal for providing a seal between the end cap and the body.

13. The plug of claim 12, wherein the second end of the end cap includes a seal for providing a seal between the end cap and a pipe engaged by the end cap.

14. A plug for sealing a pipe end substantially as hereinbefore described with reference to Figures 3 to 9. 12

15. A method of pressure testing a pipe having an end that is behind an access opening in a wall cavity, the method comprising the steps of: providing a test plug having an elongate body having a first threaded end for engaging a complementary screw thread formation on a pipe, a second end; and a bore extending between the first and second ends to define a drain passage, the elongate body being dimensioned such that when the elongate body is engaged to the end of the pipe, the second end extends through the access opening of the wall cavity ; and an end cap removably mounted to the second end to seal the drain passage; mounting the plug to the end of a pipe to be tested so as to seal the pipe end; introducing water under pressure into the sealed pipe; monitoring the water pressure; turning off the water supply; removing the end cap from the body and allowing residual water in the pipe to drain from the pipe through the drain passage and after the residual water has drained, removing the body from the pipe end.

16. The method of claim 15, wherein the test plug is the plug of any one of claims 1 to 14. 13