GB2383342A

GB2383342A - Line valve for use in preventing backflow

Info

Publication number: GB2383342A
Application number: GB0129909A
Authority: GB
Inventors: Ray Wolfenden
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-12-14
Filing date: 2001-12-14
Publication date: 2003-06-25
Also published as: GB0129909D0

Abstract

A line valve comprises a core (1) of circular cross-section inserted into a sleeve (2), optionally with a compressible, waterproof gasket (4) therebetween, the sleeve having pipe sockets (3) attached thereto such that rotation of the core prevents backflow between the sockets. Preferably, the gasket is provided with holes to admit projections (5) of the pipe (6) symmetrically inserted through, and affixed into, the valve core or integrally moulded therewith.

Description

FLOODWATER I SEWAGE PROTECTION FOR BUILDINGS This invention relates to floodwater/sewage protection for buildings.

Global climatic change is increasing the amount of rainfall in many parts of the world. More importantly, it is increasing the intensity of rainfall, leading to more frequent flooding of those areas with an established flood risk, and to the flooding of new areas with little or no flooding history. Such effects are bringing abject misery to large numbers of people unable to defend their buildings against floodwater penetration, unable to sustain repeated clean-up and repair operations, and unable to secure insurance to mitigate their loss.

Drainage pipes provide an important secondary means of floodwater/sewage entry into buildings.

Large volumes of floodwater entering main sewers under roads and streets via gullys and manhole covers for example, result in serious overloading of the sewerage system. Consequent internal pressures within the system cause venting of the combined floodwater I sewage mixture via gullys and manhole covers for example in other parts of the system, and the backflow of sewer contents into buildings via connecting drainage pipes.

Backflow will always enter a building first through the lowest drainage outlet. For example, in a domestic building without cellars this would normally be the outlet to a ground floor bath or shower tray, progressing to the outlet of a toilet or bidet, then to a sink or basin etc gradually up the building as the internal pressure within the sewerage system rises. However, such venting and backflow can initially take the form of a high-pressure back-surge which occurs just before wholesale flooding of an area, and can therefore provide a warning of imminent inundation. Any method of preventing backflow into a building will need to counteract these pressures

Backflow preventer valves installed in the underground sewer or sewer connecting pipe leading from a building have been available for some time, but are expensive to purchase, install and maintain, are prone to blockage without warning and are notoriously unreliable in the event they are required to operate. Furthermore, in sewerage applications which naturally involve the transport of semi-solids In addition to fluids in horizontal or near horizontal underground pipes, clogging of the valve aperture and closure means by trapped semi-solids and accumulated slime is inevitable, monitoring and access is difficult, and clearance is unpleasant.

For these reasons their use is restricted.

It is therefore a primary object of this invention to prevent the entry of floodwater and sewage into a building via drainage pipes during back-surge and during flood conditions, and for such prevention means to withstand the pressures arising within these pipes without distortion, dislocation or leakage for a protracted period of time at least as long as those conditions shall last.

It is another object to provide such prevention means which is inexpensive to manufacture and simple to install in both new-build and retrofit situations.

Another object is to provide such prevention means which is user-friendlyvisible, accessible, controllable, secure, dependable, and quick and easy to operate using one hand.

Another object is to provide such prevention means which is robust and durable in construction, positive in location and seal, and needing no maintenance.

Another object is to provide alternative variations of such prevention means for application according to need, from the simples to the most technically sophisticated.

Another object is to ensure harmonisation of all components with relevant British Standards.

According to the present invention there is provided a floodwater I sewage protection means for buildings having a line valve inserted into a drainage pipe leading from a water appliance or water appliances, the valve comprising a core with the shape of a cylinder, sphere, frustum of a cone or any other body of circular cross-section inserted into a close-fitting sleeve of complementary shape and a compressible waterproof gasket optionally installed therebetween, the sleeve having pipe sockets sealably fixed or integrally formed onto its external circumference in axially-aligned and diametrically-opposing positions such that when the core is rotated within the sleeve a hole or pipe formed through the core aligns with pipes installed in the sockets and waste or foul water may flow unimpeded, when the core is rotated further the through passage is sealed, and rotation of the valve is unaffected by semi-solids and the accumulation of slime.

The compressible, waterproof gasket may have two holes formed to admit projections of the pipe symmetrically inserted through, and affixed into, the valve core or integrally moulded therewith, so as to retain the gasket in place and to maintain the continuity of the pipe through the valve when the valve is in the open position.

It will be seen that the salable closure of the valve is'double-acting'-that is, operative at both sides of the valve at the same time against hydraulic pressure applied in either direction-and together with suitable pressure applied against the sealing surfaces by the gasket held in compression, this condition IS sufficient to sustain such seal for a protracted period of time at least until the threat of flooding recedes.

The core and the sleeve may be held together by a simple snap-fix circumferential 'ridge and slot'mechanism which maintains the components in the correct alignment relative to one another whilst allowing rotational movement between them, or alternatively by a bolt through a hole in the centre of a base to the sleeve, the bolt engaging with threads in a blind hole in the base of the core which in the case of a valve having a tapered core and sleeve may be used to provide in-situ variation of the contact pressure at the sealing surfaces, and thereby alter

according to application the balance between the tightness of the seals and the rotational force required to operate the valve Optionally, according to application, the core and/or the sleeve may be made from the same range of materials as the gasket, and the core expanded to take the place of the gasket, thereby simplifying manufacture and assembly.

The rotational operation of the line valve, wherever it is located, is such as to tear through or slice across any accumulated sediment or slime deposited on the bottom of the through pipe, or indeed through or across any semi-solids which may be present, in such a way as to avoid these elements restricting the operation of the valve or preventing its proper closure. This feature enables the valve to be specified confidently for pipes transporting soil or foul water in addition to those transporting relatively cleaner wastewater, and is particularly important in ensuring operation on demand-vital in the event of anticipated flooding.

The compact nature of the valve particularly on the base side makes it suitable for insertion into wall-mounted drainage runs, and for installation in retrofit situations.

With valves serving ground floor water appliances closed, the building is protected from the penetration of sewage and floodwater via the drainage system whilst at the same time allowing mainline drainage via the soil stack and sewer connecting pipe to remain open, thereby enabling water appliances to upper floors such as baths, basins, toilets etc to remain in use and when other apertures in the building envelope are also suitably sealed, the building interior to remain dry and habitable during floodwater conditions outside.

A specific embodiment of this invention will now be described in detail by way of example, with reference to the accompanying drawings in which: Figure 1 is a vertical cross-section through a valve according to this invention taken along the principal axis, showing the core inserted into the sleeve and the valve in the fully open position.

(Please note that the core and the sleeve are shown separated In the drawing purely for the purposes of identification. In practice, the core would be a sliding-fit into the sleeve, and the gasket would be slightly compressed).

Figure 2 is a vertical cross-section through a valve according to this invention taken along the principal axis, showing the core inserted into the sleeve and the valve in the fully closed position.

Figure 3 is a plan view of the exterior of the valve.

Referring to the drawings, in a first method of preventing floodwater and sewage from entering buildings via drainage pipes shown in Figures 1-3, Figure 1 shows the valve in the open position with the core 1 inserted into the sleeve 2 onto which pipe sockets 3 may be sealably attached to its external circumference in axiallyaligned diametrically-opposing positions or moulded as an integral part thereof.

The cylindrical gasket 4 made from resilient, compressible, waterproof material may have two holes formed to admit projections 5 of the pipe 6 symmetrically inserted through, and affixed into, the valve core or integrally moulded therewith.

In this condition, the pipe and the sockets are exactly aligned about the same principal axis as the valve as a whole, and with sections of drainage pipe installed into the sockets, a smooth bore of regular cross-section is available for the transport of wastewater or foulwater away from the building.

The projections 5 may comprise the entire circumference of the pipe 6 and when the gasket is installed under compression, the projections may be such as to almost equal the thickness 7 of the gasket but not so as to contact the internal surface of the sleeve, and the gasket may be such as to fill the entire separation between the core and the sleeve except for the holes to admit the pipe. The purpose of the projections is to retain the gasket in place and to maintain the

continuity of the pipe through the valve, and the purpose of the gasket is to seal the space between the moving parts represented by the core and the sleeve against the permeation of wastewater and foulwater, floodwater, and sewer contents under pressure When the core is rotated using the cap 8, the pipe 6 is able to take up a position at 90 degrees to the principal axis of the valve as shown in Figure 2, and the gasket is drawn across the apertures 9 at the base of the sockets, thereby sealably closing the valve. In this condition, the salable closure is'double-acting'-that is, operative at both sides of the valve at the same time against hydraulic pressure applied in either direction-and together with suitable pressure applied against the sealing surfaces by the gasket held in compression, this condition is sufficient to sustain such seal for a protracted period of time at least until the threat of flooding recedes. Such pressure applied by the gasket, and thereby the effectiveness of the seal, may be increased or decreased by the simple expedient of fitting a thicker or thinner gasket during manufacture, or thereafter.

The core and the sleeve may be held together by a simple snap-fix circumferential 'ridge and slot'mechanism 10 which maintains the components in the correct alignment relative to one another whilst allowing rotational movement between them. This mechanism therefore guides the opening and closing operation of the valve, and allows disassembly following installation in the unlikely event that the gasket should ever need replacement.

Materials for the core and the sleeve may be metal or plastics, or a combination of the two, and the gasket may be made from rubber, synthetic rubber, or plastics. Any metal components would need to be of a non-rusting or corroding type, or be permanently coated or encapsulated to avoid such effects. Optionally, according to application, the core and/or the sleeve may be made from the same range of materials as the gasket, and the core expanded to take the place of the gasket, thereby simplifying manufacture and assembly.

The cap may be provided with an arrow or other indication permanently etched,

moulded, or machined onto it so as to indicate the position of the valve, either open or closed, and the cap may also incorporate pegs, holes, slots or other engagement means to locate with a dedicated short-handled lever or with a screwdriver or other tool in common usage, to assist the process of rotation particularly in applications involving larger diameter drainage pipes or tighter seals. In these situations, the gasket, where appropriate, may be additionally bonded or otherwise affixed to the core to prevent it from leaving its at-rest position relative to the core during rotation of the core. A base 11 may also be optionally provided, sealably attached to the sleeve or integrally moulded therewith so as to stiffen the sleeve, avoid distortion of its sealing surfaces, and place an additional defence against the leakage of transported fluids particularly in backflow conditions. Where a base is provided, the gasket may be arranged to be in rotational salable contact with it so as to maximise internal sealing capability of the valve.

Other variations to the invention serve to increase application and use. Increasing the diameter of the core for a fixed diameter of drainage pipe will facilitate the application of multi-pipe valves capable of switching flows from a particular inlet into alternative outlets, from alternative inlets into a particular outlet, from one inlet and outlet to another inlet and outlet, or to all-closed position. Such arrangements might be used for example at the junction of drainage pipes leading from different water appliances, in more complex drainage installations, or in buildings of multiple occupation. Other shapes of core having complementary shapes of sleeve may be specified according to requirement and need. For example, a spherical core provides a greater surface area over which to achieve a seal and may be particularly suited to use where the core takes the place of the gasket as hereinbefore described, or the core may be tapered towards the base of the sleeve and a bolt through the centre of the base engaging with threads in a blind hole in the base of the core may be used to provide in-situ variation of the contact pressure at the sealing surfaces, and thereby alter according to application the balance between the tightness of the seals and the rotational force required to operate the valve.

Alternative socket jointing methods may be specified to meet installation and operation requirements, for example solvent-weld, ring-seal, compression-seal and twist-lock types in common usage, and obviously socket and valve size will vary in the same way, for example from 19mm nominal ID pipe used in domestic overflow systems through to 160mm nominal OD soil pipe used in industrial and commercial applications and residential buildings In multiple occupation. Socket dimensions and other material criteria may preferably be such as to meet relevant British Standards.

The line valve is particularly suited to installation on a branch pipe leading to a soil pipe. Transport speeds here may be significantly higher than on sewer connecting pipes leading away from buildings where backflow preventer valves are conventionally located, and branch pipes therefore are comparatively selfcleaning. The rotational operation of the line valve however, wherever it is located, is such as to tear through or slice across any accumulated sediment or slime deposited on the bottom of the through pipe, or indeed through or across any semisolids which may be present, in such a way as to avoid these elements restricting the operation of the valve or preventing its proper closure. This feature enables the valve to be specified confidently for pipes transporting soil or foul water in addition to those transporting relatively cleaner wastewater, and is particularly important in ensuring operation on demand-vital in the event of anticipated flooding.

Inside the building, drainage pipes leading to the soil pipe are more easily accessible for installation and operation of the line valve, and the compact nature of the valve particularly on the base side makes it suitable for insertion into wallmounted drainage runs, and for installation in retrofit situations. Where installation into existing pipework is required, a slip-coupling connector may be used in the event that both ends of the pipe into which the valve is fitted are fixed. The valves may be brightly coloured to assist location In the event of operation, and to identify their special function distinctively within the drainage system.

When a specific flood warning is received by any of the range of methods now in place, the valves to any ground floor water appliances such as toilets, sinks,

dishwashers, washing machines etc, may be closed in conjunction with the bringing into place of other flood protection measures to seal external ground floor openings such as doors, windows, and service apertures, for example those set out in patent application nos. GB 0125230.3 and GB 0128540.2. With the valves closed, the building is protected from the penetration of sewage and floodwater via the drainage system whilst at the same time allowing mainline drainage via the soil stack and sewer connecting pipe to remain open, thereby enabling water appliances to upper floors such as baths, basins, toilets etc to remain in use and when other apertures in the building envelope are also suitably sealed, the building interior to remain dry and habitable during floodwater conditions outside.

The simple'ridge and slot'mechanism which may be used to connect core and sleeve by progressively increasing the compressive force applied to bring the two components together, first overcomes the resistance of the continuous ridges moulded into one component, forcing the engagement flanges on the other apart then, following the application of further force, the two components move closer together ultimately enabling the ridges on one to snap into the complementary slots on the other, using the energy stored in displacing the flanges to complete the engagement.

The'ridge and slot'geometry may be moulded, cast, or machined into both components during manufacture, and using geometry of increasing sectional area the mechanism may be configured to function from as little as hand pressure, to the application of variable impact pressure to secure more-positive engagement, and to the use of a hand or power press to secure most-positive engagement.

A simple valve assembly process flows from the foregoing, bringing together all the various elements previously described.

(1) select a gasket appropriate to the application, and precoat the specified core with adhesive, if required ; (2) expand the gasket to fit over the sealing surfaces of the core and any pipe

projections which may be present, and release the gasket onto the core ; (3) complete any mechanical fixing of the gasket to the core which may be specified as an alternative to, or in addition to bonding; (4) snap-fix the core into the sleeve as hereinbefore described.

Claims

CLAIMS (1) A floodwater I sewage protection means for buildings having a line valve inserted into a drainage pipe leading from a water appliance or water appliances, the valve comprising a core with the shape of a cylinder, sphere, frustum of a cone or any other body of circular cross-section inserted into a close-fitting sleeve of complementary shape and a compressible waterproof gasket optionally installed therebetween, the sleeve having pipe sockets sealably fixed or integrally formed onto its external surface in axially-aligned and diametrically-opposing positions such that when the core is rotated within the sleeve a hole or pipe formed through the core aligns with pipes installed in the sockets and waste or foul water may flow unimpeded, when the core is rotated further the through passage is sealed, and rotation of the valve is unaffected by semi-solids and the accumulation of slime.

(2) A floodwater I sewage protection means for buildings as claimed in Claim 1, having a compressible, waterproof gasket with holes formed to admit projections of the pipe symmetrically inserted through, and affixed to, the valve core or integrally moulded therewith, so as to retain the gasket in place and to maintain the continuity of the pipe through the valve when the valve is in the open position.

(3) A floodwater/sewage protection means for buildings as claimed in Claims 1 and 2, in which the salable closure of the valve is'double-acting'-that is, operative at both sides of the valve at the same time against hydraulic pressure applied in either direction-and together with suitable pressure applied against the sealing surfaces by the gasket held in compression, this condition is sufficient to sustain such seal for an indefinite period of time at least until the threat of flooding recedes.

(4) A floodwater/sewage protection means for buildings as claimed in Claims 1-3, in which the core and the sleeve may be held together by a simple snap-fix circumferential'ridge and slot'mechanism which maintains the components in the

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correct aiignment relative to one another whilst allowing rotational movement between them.

(5) A floodwater I sewage protection means for buildings as claimed in Claims 1-3, in which the core and the sleeve may be held together by a bolt through a hole in the centre of a base to the sleeve, the bolt engaging with threads in a blind hole in the base of the core which in the case of a valve having a tapered core and sleeve may be used to provide in-situ variation of the contact pressure at the sealing surfaces, and thereby alter according to application the balance between the tightness of the seats and the rotational force required to operate the valve.

(6) A floodwater/sewage protection means for buildings as claimed in Claims 1-5, in which optionally, according to application, the core and/or the sleeve may be made from the same range of materials as the gasket, and the core expanded to take the place of the gasket, thereby simplifying manufacture and assembly.

(7) A floodwater I sewage protection means for buildings as claimed in Claims 1-6, in which the rotational operation of the line valve, wherever it is located, is such as to tear through or slice across any accumulated sediment or slime deposited on the bottom of the through pipe, or indeed through or across any semisolids which may be present, in such a way as to avoid these elements restricting the operation of the valve or preventing its proper closure and so as to enable the valve to be specified for pipes transporting soil or foul water in addition to those transporting relatively cleaner wastewater, and to ensure operation on demand.

(8) A floodwater I sewage protection means for buildings as claimed in Claims 1-7, in which with valves serving ground floor water appliances closed, the building IS protected from the penetration of sewage and floodwater via the drainage system whilst at the same time allowing mainline drainage via the soil stack and sewer connecting pipe to remain open, thereby enabling water appliances to upper floors such as baths, basins, toilets etc to remain in use and when other apertures in the building envelope are also suitably sealed, the building interior to remain dry and habitable during floodwater conditions outside.

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19% (9) A fioodwater/sewage protection means for buildings as claimed in Claims 1-8, in which increasing the diameter of the core and the complementary sleeve for a fixed diameter of drainage pipe will facilitate the application of multi-pipe valves capable of switching flows from a particular inlet into alternative outlets, from alternative inlets into a particular outlet, from one inlet and outlet to another inlet and outlet, or to all-ciosed position.

(10) A floodwater I sewage protection means for buildings as claimed in Claims 1-9, in which the core has a cap to assist rotation and the cap may also incorporate pegs, holes, slots or other engagement means to locate with a dedicated shorthandled lever or with a screwdriver or other tool in common usage, to further assist the process of rotation particularly in applications involving larger diameter drainage pipes or tighter seals.

(11) A floodwater I sewage protection means for buildings as claimed in Claims 1-10, having a line valve of very compact size relative to pipe size particularly on the base side so as to render it suitable for insertion into wall-mounted drainage runs, and for installation into existing drainage systems.

(12) A floodwater/sewage protection means for buildings substantially as described herein with reference to Figures 1-3 of the accompanying drawings.