GB2521712A

GB2521712A - Safety device

Info

Publication number: GB2521712A
Application number: GB1415421.5A
Authority: GB
Inventors: Scott Steel
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-08-30
Filing date: 2014-09-01
Publication date: 2015-07-01
Anticipated expiration: 2034-09-01
Also published as: GB201415421D0; GB2521712B; GB201315441D0

Abstract

A tubular fitting 20 for connection to a conduit 14 from a pressurised vessel, comprising; a sidewall 22, an open proximal end 24 connecting to the conduit, and a closed distal end 26. Where a passage 30 in the sidewall allows fluid 40 to vent to the exterior and directs it towards the proximal end. The passage may comprise an aperture 30 and a protrusion 28 which slopes inwardly, directing steam backwards towards an out-door wall, and may have a c-shaped or u-shaped profile. The protrusion may be formed by mechanically deforming the wall of the tubular member. This exhaust may be connected to a conduit which relieves pressure from a boiler or central heating system.

Description

Safety Device The present invention relates to safety devices for use in pipework systems. More particularly the present invention relates to an improved fitting for use at the outlet of pressure release piping, e.g. on domestic or commercial boiler systems. The invention also relates to pipework systems with such a fitting connected thereto and to methods of making and using such a fitting.

It is known in the art that many boilers and other pipework systems need to have a safety system to relief pressure should it increase beyond safe limits. It is conventional in boilers (e.g. domestic combination boilers) to have a safety release valve which acts to release pressure when a pre-set limit is reached. Such a valve is typically connected to pipework which leads out of the building though the external wall and which terminates at an outlet.

Water and steam are expelled from the outlet when a pressure release event occurs. It would be extremely inconsiderate and dangerous if the outlet directed water and steam, potentially at high pressure, away from the building. The water and steam could hit people or animals outside of the building, which would at best be unpleasant, and at worst potentially lethal. For example, if a person was walking past an outlet and was hit by high pressure steam, or even worse if the outlet is at height and a person working on a ladder or scaffolding by the outlet was hit, potential serious injury or death could result.

Accordingly, it is conventional that such outlets are adapted such that fluid which is expelled is directed back against the wall of the building where it can safely run down the wall. This can be achieved by fitting a U-bend or a double elbow bend to the end of the outlet pipe.

More recently, specific cowls for this purpose have been developed which fits onto the end of the pipe. Such a cowl is available, for example, from Flowflex Components Limited. It comprises a tubular portion adapted to fit onto a standard plumbing pipe, e.g. a 15 or22 mm copper pipe, which opens through a plurality of outlets against an umbrella-like concave plate which is curved such that fluid is deflected outwards and back against the wall of the building. The plate is held in place by spot welds. Examples of such prior art devices are shown in Fig 1.

A significant disadvantage to known systems is that they are relatively complex to fit. Known systems typically require that the pipework is passed through a hole made in the external wall of the building and then the appropriate end-piece is mounted in place. Although inconvenient, this is relatively simple when carried out near ground level. However, when working at height, e.g. in a multi-storey apartment block it can cause significant difficulties and expense to gain access to outlet at height. To avoid the need to access the outlet it is sometimes known to cut a comparatively large hole in the outer wall of the building to allow the U-bend or cowl to be fit through, and the wall is then made good. However, this is clearly disadvantageous, being time consuming, increasing the amount of damage to the wall of the building, requiring more repair work, and increasing the risk of water penetrating the repair. Furthermore, there is a danger of building materials falling from the hole in the wall posing a risk to people below and, in any event, it is not possible to repair a hole neatly and in a weather-proof manner without access to the outside of the wall. In fact, such repairs are often not satisfactory.

The end result of the difficulties with known systems is, unfortunately, that many outlets are not fitted in the correct manner, in accordance with the relevant legislation, and this is inherently dangerous.

There is thus a need for improved safety devices for pressure outlets and methods for their installation.

According to the present invention there is provided a fitting for connection to a conduit leading from a pressurised vessel, the fitting comprising a straight tubular member defining a lumen which is open at a proximal end to allow fluid from the conduit to enter the fitting, and which is closed at the distal end, the tubular member comprising a wall with a passage extending therethrough, the passage being configured such that a fluid flowing from the lumen to the exterior is directed in a proximal direction.

By proximal direction is meant that the fluid is directed back towards the proximal end of the fitting. In use this will typically be towards the wall though which the conduit passes. It will be apparent to the skilled person that fluid can be directed in any suitable direction that results in the bulk of the fluid being ejected under pressure being directed against the wall or the like, and this is covered by the term. The fluid can thus, at least theoretically be directed at any angle which is acute (i.e. less than 90 degrees) relative to the axis of the conduit (assuming the conduit is at right angles to the surface of the wall, which is usually the case).

In practice a suitable angle is typically between about 15 to 75 degrees.

Accordingly, it is preferred that the passage is inclined relative to the wall of the tubular member, e.g. at an angle of from 15 to 75 degrees from the axis of the tubular member, more preferably from 20 to 55 degrees, more preferably from 25 to 45 degrees.

Preferably the fitting has an external profile which is substantially constant along its length.

This profile is typically similar to the conduit to which it is attached. For example, the profile is preferably circular in conformity with conventional plumbing pipes, although it could be elliptical, square or any other suitable profile.

It is highly preferred that the width of the fitting at its widest point is at most only slightly larger than the width of the conduit. For a typical cylindrical fitting and conduit the width corresponds to the outer diameter. For example the maximum width is at most preferably 15 % greater than the width of the conduit, more preferably at most 10 % greater than the width of the conduit. Another way of considering this is that the entire fitting should fit substantially within a geometric cylinder having a diameter equivalent to the width of the fitting, i.e. there should be no projections outside the bounds of this cylinder. This diameter of this cylinder will typically be only 1 or 2 mm wider than the diameter of the conduit. This ensures that the fitting of the present invention can be installed without having to either provide a large hole in a wall or accessing the outside of the wall to install the fitting. This provides significant advantages in terms of ease of fitting, and consequently will result in reduced installation costs and/or higher rates of correct installation and thus greater safety.

By straight' it is meant that the tubular member does not significantly curve or contain an elbow or other substantial bend. This allows for the fitting to be easily passed through a relatively small hole, i.e. a hole essentially the size of the fitting.

Preferably the passage of the fitting comprises an aperture and fluid guiding means to direct fluid in a proximal direction. Suitably the fluid guiding means fitting comprises a protrusion which projects inwardly into the lumen of the tubular member proximal, preferably immediately proximal to the aperture.

Preferably the protrusion is defined by a portion of the wall which slopes inwardly into the lumen of the tubular member. On the outside of the tubular member, the sloped portion suitably has a generally C-or U-shaped profile, and thus forms a sloping C-or U-shaped channel on the external surface of the tubular member.

In preferred embodiments of the invention the passageway thus preferably comprises an aperture on the inside of the lumen which leads to a sloped channel. The sloped channel is suitably defined by a sloped portion of the wall of the tubular member. The slope angle of this sloped portion of the wall has an angle which generally corresponds to the intended direction of flow of the fluid. Starting from its proximal end, the sloped portion increasingly protrudes into the lumen (and the channel thus becomes deeper) towards its distal end. At its distal end the sloped portion terminates at the aperture.

Conveniently the passage formed by mechanically deforming the wall of the tubular member to form the inclined potion, e.g. by swaging. The aperture can either be formed as pad of the deforming process, or it could be formed by other means such as drilling.

The fitting of the present invention can comprise one or more passages. For example, it could comprise 1, 2, 3 or4 passages.

In a preferred embodiment the fitting suitably comprises 3 passages circumferentially spaced about the fitting. For example, the fitting can comprise three passages, spaced approximately equally (i.e. approximately 1200 apart) about the circumference of the fitting.

Versions with 2 passages spaced approximately 1800 apart, 4 passages spaced approximately 90° apart, and other configurations are also contemplated.

Where more than one passage is provided, typically the passages are all at substantially the same distance along the length of the fitting, but they could be staggered (i.e. one or more of the passages could be ata different proximal/distal distance along the length of the fitting).

The present invention thus preferably does not comprise any form of externally mounted deflection plate or a nozzle or the like. Essentially all means which direct flow of the fluid can be contained within the volume of the tubular member. This ensures that the profile of the device (i.e. its cross section) can be kept small and thus allow it to be fitted without access to the outside of a building being required, nor the formation of a large hole.

The fitting can be adapted for any type of connection to a conduit (e.g. pipe). For example, the fitting can be a solder, push-fit, press-fit or compression fitting, each of which are conventional types of coupling systems used in plumbing.

In a further aspect the invention provides a pipework system, e.g. a pressure release system connected to a pressure vessel such as a boiler, comprising a fitting according to the first aspect of present invention connected thereto.

In yet a further aspect the present invention provides a method of installing a pipework system, the method comprising providing a pipe and attaching a fitting according to the present invention to the pipe. Preferably the method comprises attaching the fitting to an outlet pipe of a pipework system. Preferably the pipework system is a central heating system or a part thereof. Preferably the pipework system is a pressure release system from a boiler, e.g. a combination boiler. The method is carried out without any need to access the exterior of the building in which the pipework is located.

In a further aspect the present invention provides a kit comprising a fitting according to the present invention and at least one pipe. The kit may comprise a suitable drill to form a hole in the external wall of a building.

Embodiments of the present invention will now be disclosed, by way of example only, with reference to the accompanying drawings in which: -Fig. 1 shows two prior are fittings for outlets; -Fig. 2 shows a schematic view of a boiler and associated pipework with a fitting according to the present invention connected to the outlet pipe; -Fig. 3a shows cross section view of a fitting according to the present invention; and -Fig. 3b shows a perspective view of a fitting according to the present invention.

Fig 1 shows two prior art fittings. The upper fitting is a cowl fitting (known as a mushroom cowl to some) which is attached onto the end of an outlet pipe. The cowl has a tubular portion and a concave end plate which a plurality of apertures discharges fluid upon, and which redirects the fluid in a proximal direction, i.e. towards the wall of the building. The apertures are simply holes in the wall of a tube from which fluid is discharged radially. The concave end plate is required to defied the water emerging from the holes to redirect the fluid in the desired direction.

The lower fitting is a conventional double-elbow' style fitting which is formed by attaching two sequential 90 degree elbow bends onto the end of the outlet pipe.

As discussed above, both of these fittings are inconvenient to install, requiring access to the outside of the wall. Furthermore, the mushroom cowl is a multi-component item, which is relatively complex to fabricate. The apertures must be form in the tubular section and the concave plate must be secured in place, e.g. by welding. This multistep fabrication results in a relatively expensive fitting. The double-elbow system requires 2 elbow bends and a middle section of pipe, and is thus also quite complex. Furthermore, three joints must be made to form the double-elbow, which can be time consuming.

S

Fig 2 shows a schematic representation of a pressure release system for a boiler that might be found in a typical house. The system comprises a boiler 10 with a pressure release valve 12. The pressure release valve is coupled to an outlet pipe 14 which passes through a hole the external wall of the building in which the system is installed. To the end of the outlet pipe a fitting 20 in accordance with the present invention is attached.

Figs 3a and 3b show the fitting 20 in more detail. The fitting comprises a cylindrical tubular member 22 having an opening 24 at a proximal end which is adapted to connect to the outlet pipe 14. This opening can have suitable means to facilitate connection of the fitting to the outlet pipe. In domestic plumbing situations the fitting will typically be joined by a solder joint. However, other connection methods may be used, for example a screw fitting, compression fitting, welding or the like. Typically the opening will have an internal diameter which corresponds to the outer diameter of a conventional plumbing pipe, e.g. 15 mm or 22 mm for conventional metric copper pipes. The fitting is fitted over then end of the outlet pipe and the joint made by the relevant technique for the type of connector (e.g. soldered, compression, push fit or press fit connection).

In the present embodiment the fitting is formed from copper, but it will be obvious that other materials such as plastics or steel could be used. The fitting is 30 mm long and has an internal diameter of 15 mm thus allowing it to be fitted over a conventional 15mm copper plumbing pipe. The wall thickness is 0.7 mm. Other dimensions would be used for fittings intended for use with other sizes of popes, e.g. 22 mm copper pipe or 1/2 or 3/4 inch imperial pipes.

The tubular member is shown to have a constant diameter and profile, and this is generally preferred. However, it is possible that the tubular member could narrow or widen to some extent, or could change to a different profile after the connection.

The tubular member 22 is closed at its distal end by a plate 26. A passage is formed though the wall of the tubular member 22. The passage is defined by an inclined protrusion 28 which slopes into the lumen of the tubular member 22. The inclined protrusion is configured such that it slopes into the lumen, the depth of the channel and hence the amount of protrusion into the lumen increasingly in the distal direction. In the present example, the inclined protrusion 28 is formed by swaging (i.e. pressing and forming) the wall inwards toward the middle of the tubular member 22. The included protrusion 28 thus defines a generally C-or U-shaped channel on the outside of the tubular member 22, the channel becoming deeper in the distal direction. At its distal extremity the channel meets with an aperture 30 connecting the lumen of the tubular member 22 with the external environment.

The aperture 30 allows fluid to pass from the lumen of the tubular member to the exterior.

The aperture 30 can be formed by the swaging process which forms the inclined protrusion and channel, or it can be formed by another method, e.g. drilling -a combination of these methods can be used, e.g. the wall is thinned/stretched during the swaging process which forms the channel (which could partly form the aperture) and the aperture is then either formed or finished off by drilling.

Fig 3a shows arrows 40 which indicate the direction of flow of fluid through the fitting 20 when there is a release of fluid through the outlet. It can be seen that the fluid flows through the lumen of the tubular member towards the end plate 26. It then curves around to exit the lumen of the tubular member through the aperture 30 and into the channel defined by the inclined protrusion 28. The direction in which the fluid exits the fitting corresponds generally to the angle defined by the inclined protrusion 28. This is important because it means that the fluid is directed in a proximal direction, i.e. towards the wall. It is obvious that the overall direction of movement of the fluid exiting the fitting has both and outward (e.g. radial) component and a proximal component, but it is sufficient from a safety point of view that the majority of the fluid ejected has a sufficient proximal direction component that it hits the wall and therefore safely runs down the wall.

If a simple aperture were provided on the side of the tubular member (i.e. without associated configuration of the conduit) this would not achieve the desired result as the fluid would simply exit in a radial direction and would thus not be safely directed against the wall. This is why the mushroom cowl of the prior art requires the convex plate to redirect the fluid in a proximal direction. Such a plate is not required in the present invention because of the configuration of the channel and aperture. This provides a significant advantage as it means safe discharge of fluid can be achieved without the need for an external and comparatively wide cowl.

Without wishing to be bound by theory, the reason why the water is directed so effectively in the proximal direction would appear to be a combination of the eddy effect of the water passing around the inclined protrusion 28, which creates an area of low pressure immediately downstream of the protrusion, in combination with the reflection of the fluid caused by the plate 26. It is, however, somewhat surprising that such a pronounced and effective redirection of the fluid is achieved without the need for any external deflector or a nozzle. One might expect that absent a clearly defined nozzle to clearly confine and redirect the fluid that it would spray in a relatively uncontrolled way. However, in practice this is not found to be the case. In the fitting described the correct direction of the fluid is achieved by the conformation of simple internal features of the fitting. This is extremely useful as it means an effective fitting can be made using the minimum amount of material and though a very simple manufacturing process which avoids the need for multiple components of the formation of complex shapes.

Installation of the fitting is straightforward. It is simply attached to the outlet pipe, which is then passed through a hole in the wall to the exterior of the building. The hole need not be significantly wider than the outlet pipe, e.g. a hole of 17mm should be sufficient for a fitting on a 15mm pipe, i.e. 15mm for the pipe plus 1.4 mm for the thickness of the fitting plus additional clearance. And gaps which remain can be filled very easily with a suitable filler material. Thus access to the external location of the outlet is not required.

To manufacture a fitting according to the present invention a piece of closed end tubing of the desired length is provided (e.g. 30 mm long). The tubing is placed on a suitable mandrel to support the general shape of the tubing. A swage is then used to press the inclined channel in the outside surface of the tube, with the mandrel supporting the surrounding surface of the tube to control the swaging process. If required the aperture, can then be formed or finished by drilling. Further finishing to remove any rough edges can then be carried out if required.

Various modifications to the specific embodiments can, of course, be made without departing from the spirit and scope of the present invention. For example, a particularly preferred version of the fitting comprises three passages, each spaced 1200 apart about the circumference of the fitting. Typically the three passages are at the same distance along the length of the fitting, but they could be staggered (i.e. at different proximalldistal distances along the fitting).

Claims

Claims 1. A fitting for connection to a conduit leading from a pressurised vessel, the fitting comprising a substantially straight tubular member defining a lumen which is open at a proximal end to allow fluid from the conduit to enter the fitting, and which is closed at the distal end, the tubular member comprising a side wall with a passage extending therethrough, the passage being configured such that a fluid flowing from the lumen to the exterior is directed in a proximal direction.
2. The fitting of claim 1 wherein the direction of fluid flow is at an acute angle of 15 to 75 degrees relative to the axis of the conduit.
3. The fitting of claim 2 wherein the direction is 25 to 45 degrees relative to the axis of the conduit.
4. The fitting of any preceding claim which has an external profile which is substantially constant along its length.
5. The fitting of any preceding claim which has a substantially circular cross-section.
6. The fitting of any preceding claim wherein the width of the fitting at its widest point is at most only slightly larger than the width of the conduit.
7. The fitting of any preceding claim wherein the passage comprises an aperture and fluid guiding means to direct fluid in a proximal direction.
8. The fitting of claim 7 wherein the fluid guiding means fitting comprises a protrusion which projects inwardly into the lumen of the tubular member immediately proximal to the aperture.
9. The fitting of claim 8 wherein the protrusion is defined by a portion of the wall which slopes inwardly into the lumen of the tubular member in a distal direction.
10. The fitting of claim 9 wherein on the outside of the tubular member the sloped poition has a generally C-or U-shaped profile and thus forms a sloping C-or U-shaped channel on the external surface of the tubular member.
11. The fitting of any one of claims 8 to 10 wherein the protrusion is formed by mechanically deforming the wall of the tubular member.
12. The fitting of any preceding claim which comprises 1, 2, 3 or 4 passages.
13. The fitting of any preceding claim which comprises 3 passages spaced circumferentially about the fitting.
14. The fitting of claim 13 wherein the passages are spaced approximately 1200 apart.
15. The fitting of any preceding claim which does not comprise any form of externally mounted deflection plate or a nozzle.
16. A pipework system comprising a fitting according to any one of claims ito 15.
17. A method of installing a pipework system, the method comprising providing at least one pipe and attaching a fitting according to any one of claims ito is to the pipe.
18. The method of claim 17 which comprises attaching the fitting to an outlet pipe of a pipework system and passing the outlet pipe through an external wall of a building from the inside to the outside.
19. The method of claim 17 or 18 wherein the pipework system is a central heating system or a part thereof.
20. A kit comprising a fitting according to any one of claims ito 15 and at least one pipe.
21. A method of manufacturing a fitting according to any one of claims ito 15, the method comprising providing a piece of closed end tubing, forming a fluid guiding means in the surface of the tubing in the form of a protrusion which projects inwardly into the lumen of the tubular member, forming an aperture at the distal end of the protrusion thus forming a passage which fluidly connecting the lumen of the closed end tubing with the exterior.
22. The method of claim 21 wherein the fluid guiding means is formed by swaging.
23. The method of claim 21 or 22 wherein the fluid guiding means is a sloping C-or U-shaped channel on the external surface of the tubular member.
24. The method of any one of claims 21 to 23 which comprises forming 3 passages with associated fluid guiding means spaced circumferentially about the fitting.