GB2475093A

GB2475093A - Siphon draining device with an air valve to remove air locks for draining a tank

Info

Publication number: GB2475093A
Application number: GB0919478A
Authority: GB
Inventors: David Clacy
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-11-06
Filing date: 2009-11-06
Publication date: 2011-05-11
Also published as: GB0919478D0

Abstract

The invention relates to drainage device (20 figure 3) for removing liquid and/or sediment from a tank via a drainage aperture 32 in a side wall of the tank. The device comprises a pipe 23 having an inlet aperture (34 figure 3), an outlet aperture and an air release valve 25. The outlet aperture is arranged to be connected to the tank drainage aperture 32 such that the pipe can be fixed in a generally upright orientation with the inlet aperture (34 figure 3) situated at or near the base 1 of the tank to allow liquid or sediment to be drawn in and removed from the tank via the outlet aperture 32. The air release valve 25 is situated above the outlet aperture 32 whilst the pipe 23 is in the upright orientation. A drainage operation is preferably initiated by a siphoning action by opening an exterior valve or pump (not shown). The purpose of the air release valve 25 is to remove any air lock that develops in pipe sections (22 figure 3), 23 and 26 as the siphoning action is initiated.

Description

Drainage Device

Field of the Invention

The present invention relates to a drainage device, particularly a liquid tank or cistern drainage device and a method of installing the same.

Background of the Invention

Most homes have a water tank or cistern for supplying hot and cold water through pipes running from the tank to outlets, for example taps or washing machine valves. The water tank is generally located in a raised location within the home, usually the loft, and works due to gravity causing water to leave the tank when a valve situated below the tank is opened, for example when someone opens a tap.

There is a requirement to drain water tanks periodically. One important reason is to remove sediment which tends to build up at the bottom. Sediment can harbour or provide nutrients for bacteria and other organisms. One drainage system is illustrated in Figure 1 which shows a water tank 1 supported on a base 3 with a feed or distribution pipe 5 connected to a side wall for supplying water to appliances below. A drainage outlet 7 is provided in the base of the tank 1 for reducing sediment retention. This type of drainage outlet 7 is useful in that it allows removal of a substantial amount of sediment, although there will still remain about 6 mm of sediment at the base due to the thickness of the flange. However, it requires a hole to be made in the fully supported base 3 to access the outlet and to feed a drainage pipe 9 to it. This is not only an inconvenient and rather complicated operation, but strictly-speaking is contrary to certain regulations which require the base to be solid, i.e. with no such apertures.

An alternative approach is to drain sediment from the side of the tank, as illustrated in Figure 2. Here, the same tank 1 is shown but with a drainage outlet 11 connected to the side wall of the tank by a cistern connector 6. The dimensions of the cistern connector 6 and the rounded edges of the base of the tank mean that the outlet will be at least 20 mm above the base of the tank 1. This setup is preferable in that it is far simpler for a plumber to install and access the drainage system, but tends to be less efficient at draining the tank and removing sediment due to its higher position above the base. To achieve full drainage and substantial sediment removal, the plumber has to remove the remainder of the water and sediment by hand, e.g. using a bucket.

Summary of the Invention

According to a first aspect, there is provided drainage apparatus for removing liquid and/or sediment from said tank via a drainage aperture in a side wall thereof, the apparatus comprising a pipe having an inlet aperture, an outlet aperture and an air release valve, wherein the outlet aperture is arranged, in use, to be connected to the tank drainage aperture such that the pipe can be fixed in a generally upright orientation with the inlet aperture situated at or near the base of the tank to allow liquid or sediment to be drawn in and removed from the tank via the outlet aperture, the air release valve being situated above said outlet aperture.

The apparatus can be fitted within a fluid tank, such as those illustrated in Figures 1 and 2, and operates to control the amount of sediment present at the base of the tank, as well as providing a convenient means of draining the tank completely of water. In this context, the term drainage' does not mean that the apparatus is suited solely for empyting the tank; indeed, the drainage apparatus may be in continuous use during everyday operation.

According to a second aspect, there is provided drainage apparatus for removing liquid and/or sediment from the interior of a fluid tank via a side wall thereof, the apparatus comprising a pipe member arranged, in use, to be connected to an external drainage system via a side wall of the tank and, when so connected, to extend downwardly to a position at or near the base of the tank in order to be able to draw liquid and/or sediment through an inlet aperture located at or near the lower end of the pipe for removal via an outlet aperture in communication with the exterior drainage system.

The apparatus may further comprise an extension element located at or near the lower end of the pipe, the extension element having a greater cross-sectional area than said pipe lower end.

The extension element may include a wall having a lower edge arranged, in use, to sit on the base of the tank and further comprises one or more aperture(s) therein for allowing sediment and/or fluid to pass through the extension element to the inlet aperture of the pipe. The or each extension element aperture may be defined by a recess extending upwardly from the lower edge. The or each recess may extend upwards by between 1 and 5 mm. The extension element may comprise a circumferential skirt arranged substantially concentric to the pipe.

The extension element is, in the preferred embodiment, detachable and comprises a watertight screw or push fitting. The extension element may be formed of, at least partly, a plastics material. The apparatus may further comprise a drainage pipe connected to the outlet aperture for removing fluid and/or sediment through the side wall of the tank, the drainage pipe extending substantially perpendicular to the uprightly oriented pipe.

The air release valve can comprise a float-type valve. The air release valve can comprise a normally-shut valve arranged, in use, to open when the air pressure within the pipe reaches a predetermined level due to liquid being drawn from the tank through the pipe.

The pipe is, in the preferred case, generally T-shaped and may be formed of a number of separate parts or one integrally formed piece.

According to a third aspect, there is provided a removable extension element for use with the apparatus as defined previously with regard to the first and second aspects. The extension element may comprise a wall having a lower edge arranged, in use, to sit on the base of the tank together with instructions for forming one or more aperture(s) therein for allowing sediment and/or fluid to pass through the extension element to the inlet aperture of the pipe.

According to a fourth aspect, there is provided a method of installing a drainage apparatus according to any one of claims 3 to 14, comprising: (1) cutting the pipe member so that, when connected in its generally upright orientation within the tank, its lower end is spaced above the tank base; (2) connecting a removable extension element at or near the lower end, the extension element having apertures provided therein; (3) connecting the pipe member within the tank to an exterior drainage system via an aperture in a side wall of the tank; and (4) locating the extension element on the base of the tank.

According to a fifth aspect, there is provided a siphoning apparatus comprising a pipe which, in use, is connected in a substantially upright orientation within a fluid tank by means a transverse outlet part when connected to a side wall of the tank, the lowermost part of said pipe including one or more cuts or apertures into which liquid and/or sediment can be drawn upon initiation of a siphoning action for removal through the side wall by means of the transverse outlet part. The apparatus may further comprise an air release mechanism to aid initiation of the siphoning action, for example an air release valve located above the central axis of the transverse part. The lowermost part of the pipe may have a greater cross sectional area than the remainder of the pipe above it.

Brief Summary of the Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figures 1 and 2 show side-sectional views of prior art arrangements for removing sediment from a water tank; Figure 3 is a perspective exploded view of components comprising an embodiment of a drainage apparatus according to the invention; Figure 4 is a perspective view of the assembled components shown in Figure 3; Figure 5 is a side-sectional view of the drainage apparatus installed within a water tank, part of which is shown in section; Figures 6 and 7 are side-sectional views of a float-type air release valve forming part of the drainage apparatus, in closed and open states respectively; and Figure 8 is a partial view of a lower pipe section as may be used in an alternative embodiment.

Detailed Descrirtion of a Preferred Embodiment Referring to the Figures, there will now be described a drainage apparatus 20 for placement within the interior of a water tank 1. The drainage apparatus 20 may be retrofitted to existing water tanks and is suited, in use, for removing sediment and/or water through the side-wall of the tank with an improved performance compared with prior art methods.

Figures 1 and 2 show side-sectional views of a typical water tank 1. The drainage apparatus is arranged, in use, to be connected to an aperture in an upright wall of the tank so that sediment and water can be drained through the side, rather than the base of the tank 1.

Referring to Figure 3, the drainage apparatus 20 is shown in exploded perspective view with each constituent part shown. A central T-shaped pipe 22 is connected to a lower pipe portion 23 at one side and to an air release valve 25 at the other, opposite, side. The lower pipe portion 23 is connected to a skirt member 24 at or in the region of its lower end, Le.

opposite the end connected to the T-shaped pipe 22. Each connection can be made using any known plumbing fitting, for example a water-tight push or screw -type fitting. The connection between the lower pipe portion 23 and skirt member 24 is in this case made by pushing the lower end of the pipe through a rubber collar 27 which has a central aperture narrower than the diameter of the lower pipe portion 23. The skirt member 24 is provided in the form of plastic cylinder which is open at its lower end to define a circular, lower edge 28, substantially concentric to the inlet aperture 34 at the end of the lower pipe portion 23. A plurality of recesses 29 are formed in the lower edge 28, extending upwardly by approximately 2 mm in this case.

The drainage apparatus 20 is completed by a transverse drainage pipe 26 that is connected to the third arm of the T-shaped pipe 22. As indicated in Figure 4, said transverse pipe 26, in use, connects the assembled drainage apparatus 20 to an aperture 32 formed in the side wall of the water tank 1. In practice, this is achieved by connecting the transverse pipe 26 to an interior connector flange 30 with an exterior drainage pipe 11 connected to an exterior connector flange 31 transporting the removed fluid and sediment.

Referring to Figures 4 and 5, the above-described drainage apparatus 20 is in use situated within the interior of the water tank 1 with the lower edge 28 of the skirt member 24 seated on the base 1' of the tank 1. The principal axis of the T-shaped pipe 22, the lower portion 23 and the air-release valve 25 together define an upright axis, substantially parallel with the side of the tank 1 and perpendicular to the base 1', though appreciable variations from this strict orientation can be employed provided the inlet aperture 34 is downwardly directed towards the base 1' and the air release valve 25 is above the connecting point of the transverse pipe 26 to the T-shaped pipe 22.

A drainage operation is performed by initiating a siphoning action, e.g. by opening an exterior valve or pump (neither shown). Fluid and sediment is consequently drawn through the inlet aperture 34 at the end of the lower pipe portion 23, via the skirt apertures 29, and passes along the transverse pipe 26, through the wall aperture 32 and downwards through the exterior drainage pipe 11. The purpose of the air-release valve 25 is to remove any air lock that develops in the T-shaped pipe 22, lower pipe portion 23 and transverse pipe 26 as the siphoning action is initiated. This will be descried in further detail below.

The skirt member 24 serves a number of purposes. It is effectively an extension of the lower pipe portion 23 with the cuts or apertures 29 enabling improved sediment removal by virtue of them being situated within the tank, directly adjacent the tank base 1' as opposed to 20 mm above the base, as is the case shown in Figure 2. By making the height of the apertures 29 smaller than 20 mm, improved sediment removal is ensured. The same effect could of course be achieved by providing one or more cuts in the pipe side wall at the inlet end 34 (see Figure 8) in which case the skirt may not be required. However, the greater diameter of the skirt member 24, by virtue of its increased cross-section, draws a greater amount of water and so sediment into the region beneath the inlet end 34 for removal through the apparatus, with the flow speed of the fluid and sediment also being increased.

In this embodiment, the skirt member 24 is cylindrical is shape and the lower edge 28 defines a substantially concentric circle to the lower pipe portion 23. Alternative shapes for the skirt member 23 can be employed, e.g. frusto-conical, so long as at least part of its cross sectional area is greater than the inlet end 23 of the lower pipe 23. The skirt member 23 is preferably made of a plastics material which enables the installer to make cuts in the bottom edge which provide the apertures 29.

As an extension of the lower pipe portion 23, the skirt member 23 also helps maintain a substantially constant gap between the inlet end 23 and the tank base 1'.

The skirt apertures 29 are preferably between 1 mm and 5 mm in height to ensure a greater amount of sediment is removed than with the conventional method, as shown employed in Figure 2. The size of the apertures 29 is chosen such that the combined area of at least two apertures is equal or greater than the full bore area of the pipe inlet end 34; in this way, should one or two of the apertures 29 become blocked with sediment, there is sufficient area for the siphoning action to continue.

As briefly mentioned above, the air release valve 25 serves to release any trapped air within the siphon below it. The position of the valve 25 should be above the elbow formed by the T-shaped member, indicated by the axis marked X in Figure 5, to ensure substantially all trapped air will be removed to allow the siphoning effect to continue. In this case, the valve is substantially aligned with the upright axis but it will be appreciated that this is not essential. The valve can be situated, for example, along the transverse member 26.

Different types of air release valve 25 may be employed. Here, a float-type valve is employed and its operation will be described with reference to Figures 6 and 7.

Referring to Figure 6, the valve 25 is shown in its closed position. The valve 25 comprises a hollow cylindrical body 40 and cap 41, the two being connected in a cylinder-piston type arrangement by means of a pin 42. The pin 42 terminates with a circular plate 43 which, in the state shown, rests on a tubular seat 44 to seal an air passage 46 from the upper section of the body 40. Holes 45 are provided in the wall of the upper body 40 to enable air to pass from the interior to the exterior of the body 40 when the valve is open. Figure 7 shows the valve 25 in said open position in which pressure from an underlying system, the assembly of members 22, 23 and 24 in this case, causes the circular plate 43 to be displaced upwards from the seat 44 to allow the release of air through holes 45. In the context of the present embodiment, water in the tank 1 flows into holes 45 to keep the valve closed until a predetermined level of air pressure (sufficient to raise the plate 43 and the water above it) occurs as the siphon draws water upwards, after which its opening allows the air to be released as bubbles through the holes 45.

The drainage apparatus 20 has particular advantages in that it can be retrofitted to almost any type of liquid tank so long as a hole can be made in a side wall of the tank. A method of installation will now be described. It will be assumed that a hole has already been made in the tank side wall.

Before use, the installer checks that the inlet end 34 of the lower pipe portion 23 will be above the tank base 1' when the apparatus 20 is connected to the flange 30, i.e. so that there is a gap through which fluid and sediment can pass. If not, the lower pipe portion 23 is cut to the appropriate length before the apparatus is connected to the interior flange 30. The skirt member 24 is then fitted by passing the inlet end 34 through its collar 27 to form a watertight seal. The position of the skirt member 24 is then adjusted with respect to the terminating end 34 of the lower pipe portion 23 so that its lower edge 28 sits on the base 1', as shown in Figures 4 and 5.

The constituent parts of the drainage apparatus 20 can be supplied as shown in Figure 4, i.e. assembled, perhaps with the exception of the skirt member 24, or as separate members for connection by a plumber on-site. The skirt member 24 may be supplied with apertures 29 pre-cut or with instructions allowing a plumber to make cuts into the cylindrical wall using a knife or scissors. In this way, the plumber can decide on the height of the apertures 29 extending upwards from the base.

Claims

Claims 1. Drainage apparatus for removing liquid and/or sediment from a tank via a drainage aperture in a side wall thereof, the apparatus comprising a pipe having an inlet aperture, an outlet aperture and an air release valve, wherein the outlet aperture is arranged, in use, to be connected to the tank drainage aperture such that the pipe can be fixed in a generally upright orientation with the inlet aperture situated at or near the base of the tank to allow liquid or sediment to be drawn in and removed from the tank via the outlet aperture, the air release valve being situated above said outlet aperture whilst the pipe is in said upright orientation.
2. Drainage apparatus for removing liquid and/or sediment from the interior of a fluid tank via a side wall thereof, the apparatus comprising a pipe member arranged, in use, to be connected within the tank to an external drainage system via a side wall and, when so connected, to extend downwardly to a position at or near the base of the tank in order to be able to draw liquid and/or sediment through an inlet aperture located at or near the lower end of the pipe for removal via an outlet aperture in communication with the exterior drainage system.
3. Apparatus according to claim 1 or claim 2, further comprising an extension element located at or near the lower end of the pipe, the extension element having a greater cross-sectional area than said pipe lower end.
4. Apparatus according to claim 2 or claim 3, further comprising an extension element located at or near the lower end of the pipe, wherein the extension element includes a wall having a lower edge arranged, in use, to sit on the base of the tank and further comprises one or more extension element aperture(s) therein for allowing sediment and/or fluid to pass through the extension element to the inlet aperture of the pipe.
5. Apparatus according to claim 4, wherein the or each extension element aperture is defined by a recess extending upwardly from the lower edge.
6. Apparatus according to claim 5, wherein the or each recess extends upwards by between 1 and 5 mm.
7. Apparatus according to any one of claims 3 to 6, wherein the extension element comprises a circumferential skirt arranged substantially concentric to the pipe.
8. Apparatus according to any one of claims 2 to 7, wherein the extension element is detachable.
9. Apparatus according to claim 8, wherein the extension element comprises a watertight screw or push fitting.
10. Apparatus according to claim 9, wherein the extension element is formed of a plastics material.
11. Apparatus according to any preceding claim, further comprising a drainage pipe connected to the outlet aperture for removing fluid and/or sediment through the side wall of the tank, the drainage pipe extending substantially perpendicular to the uprightly oriented pipe.
12. Apparatus according to any preceding claim, wherein the air release valve comprises a float-type valve.
13. Apparatus according to any preceding claim, wherein the air release valve comprises a normally-shut valve arranged, in use, to open when the air pressure within the pipe reaches a predetermined level due to siphoning.
14. Apparatus according to any preceding claim, wherein the pipe is generally T-shaped.
15. A removable extension element for use with the apparatus according to any one of claims 3 to 14.
16. An extension element according to claim 15, comprising a wall having a lower edge arranged, in use, to sit on the base of the tank and instructions for forming one or more aperture(s) therein for allowing sediment and/or fluid to pass through the extension element to the inlet aperture of the pipe.
17. A method of installing a drainage apparatus according to any one of claims 3 to 14, comprising: (1) cutting the pipe member so that, when connected in its generally upright orientation within the tank, its lower end is spaced above the tank base; (2) connecting a removable extension element at or near the lower end, the extension element having apertures provided therein; (3) connecting the pipe member within the tank to an exterior drainage system via an aperture in a side wall of the tank; and (4) locating the extension element on the base of the tank.
18. Siphoning apparatus comprising a pipe which, in use, is connected in a substantially upright orientation within a fluid tank by means a transverse outlet part when connected to a side wall of the tank, the lowermost part of said pipe including one or more cuts or apertures into which liquid and/or sediment can be drawn upon initiation of a siphoning action for removal through the side wall by means of the transverse outlet part.