Integrated, insulated valve for heat pump systems

Abstract

An integrated insulated valve for use in heat pump installations comprises an isolation valve part 19, 20, 21, a strain part 23, 24, an antifreeze part 26, 27, and a vacuum breaker part 29, the parts

Description

31 10 25 INTEGRATED, INSULATED VALVE FOR HEAT PUMP SYSTEMS Technical field

[0001] Heat pump systems require an assembly of: an isolation valve, a strain fixture, a drain cock, an antifreeze valve, a vacuum breaker and optionally a second isolation valve. The assembly is usually installed in water heating circuit at the inlet side of the heat pump to deliver cooled water to the heat pump. Prior art

[0002] A prior art assembly is shown in figure 1. The assembly needs to be assembled, on site, from individual component valves, each ordered and purchased as separate components, using conventional pipe coupling techniques such as soldering, compression fittings, BSP or other non-threaded fittings or mechanical push fitting. All these fittings will be ISO or ANSI clearance fits which facilitate assembly on site without workshop tools. A seal is achieved in the clearance gap using; a solder to fill the clearance gap, or a resilient seal such as an olive or “O” ring. The joint can be disassembled on site, for example by remelting the solder or unscrewing a threaded part using a conventional spanner. In the case of a mechanical push fit, an element of the fitting must be displaced against a bias to remove a load applied to jaws which grip the pipe.

[0003] The purchasing process provides an opportunity to introduce error via incorrectly ordering or incorrectly fulfilling a correct order, adding to the time taken to complete the heat pump project. Each assembly requires coupling to a supply side pipe 1, in this prior art example via a 28mm compression coupling 2 communicating with an upstream port of an upstream isolation valve 3 (flow in the figures is from left to right). The downstream port of the upstream isolation valve 3 is coupled via a downstream isolation valve compression coupling 4 to a first short communicating length of 28mm copper pipe 5. This first communicating copper pipe facilitates downstream communication with an upstream port of a strain fixture 6 by means of a corresponding upstream strain compression coupling 7. The strain fixture includes a sleeve 8 having a threaded service port from which an internal strain element of the fixture can be removed for servicing. The port is normally closed by a threaded plug 9. A further 31 10 25 communicating length of pipe 11 is coupled to a downstream compression coupling port 11.1 of a “T” fixture 11.2 having a threaded 22mm port 11.3 on the “T” branch. A conventional stop cock 11,4 is threaded into the port 11.3 to facilitate draining the valve assembly during servicing. An upstream compression coupling 11.4 couples with a further length of copper pipe 11.5 which communicates with an antifreeze valve 12 via an upstream antifreeze valve compression coupling 13. A downstream antifreeze valve compression fitting 14 which is coupled to the downstream discharge port to discharge water to the heat pump, either via a further length of copper pipe or directly to the heat pump unit. In some cases, a further downstream isolation valve may be installed to facillitate complete isolation of the strain and antifreeze valve assembly for servicing.

[0004] , Each coupling requires pipe of appropriate dimensions to be made available, cut to appropriate length, the ends deburred and cleaned before connection irrespective of the particular type of coupling. This is laborious and therefore expensive and is liable to introduce errors in assembly which must be checked for and if present corrected.

[0005] K location must be found on the site able to accommodate the assembly, which is often not convenient to the heating engineer and / or the customer as the valve assembly will be about 350mm long, depending on how short the pipe lengths are made and the particular brand of valve fittings used.

[0006] Finally, the assembly must be wrapped in a thermal insulator. Because of the very irregular external contour of the assembly this is usually done with some form of foam thermal insulating tape or ribbon. This initial wrapping is laborious and unsightly. The tape must be retained by adhesive tape, string, wire, cable ties or some combination thereof and the efficacy and elegance of the result is therefore uncertain. This makes subsequent servicing laborious, because the entire mess of insulation must be removed to inspect the assembly and, any carelessness is likely to result in damage to the insulating tape, which must then either be replaced with new or replaced in a damaged condition.

[0007] It should be noted that in the case of some installations an assembly with only one isolation valve, preferably upstream, may be provided, principally to reduce the size of the assembly in order to fit in an available location. 31 10 25

[0008] , In general, two assemblies will be required for each heat pump installation, one on the input to the heat pump and one at the output.

[0009] It is an object of the present invention to provide an integrated, insulated valve which mitigates at least some of the disadvantages of the prior art described above. Summary of the Invention First aspect

[0010] An integrated insulated valve for use in heat pump installations comprising at least: an isolation valve part; a strain part; an antifreeze part; and; a vacuum breaker part said isolation valve part, the strain part, the antifreeze part and vacuum breaker part being factory integrated and provided with site couplings at an upstream port and a downstream port to form an integrated valve. [ooh]. Preferably the integrated valve comprises a single housing machined from a single brass casting having features into which each of an isolation valve, a strain assembly and drain cock, an antifreeze device and a vacuum breaker are installed. The drain cock may be replaced with a threaded plug.

[0012] An isolation valve part of the integrated valve typically incorporates a ball into a main fluid passage formed in the valve body. The ball is mounted to rotate on an axis perpendicular to the direction of fluid flow through the valve bore. A hole is formed into the ball which, by rotation on the axis is, brought into alignment with the fluid passage to permit flow and misaligned to isolate fluid flow. To assemble the valve a ball chamber formed in the valve body must be exposed to receive the ball and facillitate coupling with a spindle by means of which the ball is rotated in use. The ball is retained by a cap part irremovably factory assembled to the isolation valve body, commonly with an interference fit. Conveniently the cap part will provide a conventional form of pipe coupling to be coupled to a supply or discharge pipe. 31 10 25

[0013] , Conventional pipe couplings include a selection of any one of a compression fitting, solder fitting, BSP fitting or push fit.

[0014] The strain part may be disposed adjacent the isolation valve and comprise a feature in the form of a sleeve inclined at an obtuse angle to water flow axis in the main passage, whereby a cylindrical strain mesh may be introduced into an integrated valve main passage through which the water will flow. The sleeve may be threaded at the end distal from the main passage to provide the feature to receive the drain cock. Removing the drain cock facilitates maintenance of the strain mesh.

[0015] Preferably downstream of the strain part, the integrated valve includes an antifreeze accommodating feature provided by a threaded hole bored perpendicular to the integrated valve bore in which an antifreeze device is received.

[0016] A perpendicular vent threaded bore feature is provided to accommodate a vent device to vent air or vapour from the integrated valve bore. The vent threaded bore feature is preferably located diametrically opposite the antifreeze accommodating feature.

[0017] The integrated valve has a conventional downstream port coupling to couple to downstream pipework or directly to a heat pump.

[0018] Although forming the integrated valve with a single housing is preferred the invention also contemplates factory joining housing parts using an interference fit between the parts such that the parts cannot be separated on site and ensure a hydraulic seal. Such an integrated valve can be factory tested to ensure each part is without fault before packaging for delivery.

[0019] The integrated valve is of a fixed size and configuration so facilitating the provision of an insulating enclosure which encloses the integrated valve when the valve is installed. The enclosure is preferably formed from two or more parts adapted to be assembled around the integrated valve. In a preferred embodiment the two parts are an upper part and a top part and a bottom part. Each of the top and bottom part may conveniently be formed from an expanded foam insulator shaped in a mould. A bottom surface of the top part has a longitudinally extending channel sized and shaped to receive the top part of the integrated valve housing. An isolation valve formation cavity extends up from the channel to accommodate the upper portion of the isolation valve. The isolation valves may have a spindle head without a handle, and adapted to be 31 10 25 rotated by a screwdriver or wrench, for example a flat head, standard socket or nut head in order to facilitate accommodation in the upper part of the insulating enclosure.

[0020] A vent cavity may be provided in the insulating enclosure upper part to accommodate the vent assembly. Preferably the vent cavity leads to a vent discharge passage.

[0021] The bottom part of the insulating enclosure is preferably formed by moulding an expanded foam insulating material and has a longitudinally extending channel to accommodate the integrated valve and cooperate with the corresponding upper insulating enclosure channel. The bottom part includes a strain cavity to accommodate the strain part sleeve. The bottom part preferably includes a thermostatic assembly cavity to accommodate the thermostatic assembly. The thermostatic cavity will have a discharge passage to facilitate the discharge of water from the thermostatic assembly where it will usually simply drip onto the ground.

[0022] The insulating enclosure top and bottom parts are brought together around the integrated valve so that an upper mating face of the bottom part mates with a lower mating face of the top part. Cooperable shoulder features may be formed on the mating faces sized such that the top and bottom parts can be manually pushed together or pulled apart but will not come apart under their own weight. Second aspect

[0023] According to a second aspect of the present invention there is provided a method of fabricating an integrated valve for use in a heat pump installation comprising: casting a housing with each of an isolation valve part, a strain part, an antifreeze part and a vent part; machining features into the housing to receive the components of; an isolation valve, a strain, an antifreeze device and a vent device; machining upstream and downstream coupling ports.

[0024] The integrated valve may be completed by the steps of installing the components of an isolation valve into the isolation valve part, notably the ball and spindle. The strain part may be completed by the step of factory installing a strain and retaining the strain by means of a threaded plug or stop cock. The antifreeze part may be completed by 31 10 25 factory installing an antifreeze device to the antifreeze part and a vapour vent assembly to the vent part. Conveniently the vapour vent assembly may be installed diametrically opposite the antifreeze device.

[0025] Moulding an insulating enclosure to fit around the integrated valve. Third Aspect

[0026] According to a third aspect of the present invention there is provided a method of assembling an integrated valve for use in a heat pump installation wherein the integrated valve comprises an isolation valve part, a strain part, and a thermostatic and vent part; each part having a separate housing part; inseparably joining each housing part to at least one other housing part to form a continuous main passage from an inlet port to an outlet port of the integrated valve.

[0027] The permanent joints are not capable of being disassembled on site and are generally impossible to disassemble without workshop tools. Such joints include welding, soldering and interference fits and avoid the prior art requirement for intervening lengths of pipe. Interference fits may be threaded or sliding but will require the application of heat to assemble or disassemble.

[0028] Preferably the integrated valve assembly is subject to a factory testing and inspection steps to confirm there are no faults such as leaking couplings.

[0029] Preferably an insulating enclosure is factory fabricated to closely fit around the integrated valve assembly. This is possible and convenient because the shape and configuration of the integrated valve is predetermined. Conveniently the insulating enclosure will be formed from a thermally insulating material such as expanded foam. The enclosure may be formed from two parts each containing cavities to accommodate the irregular projecting features of the integrated valve. Features such as the thermostatic assembly and the vent assembly require passages to discharge liquid or vapour to the surroundings to function. Passages are provided in the insulating enclosure to facilitate the discharge of fluids from the thermostatic assembly and vent assembly. 31 10 25 Fourth aspect

[0030] K method of installing an insulated integrated valve according to the first aspect into a heat pump system having a supply pipe and an exhaust pipe comprising: coupling a port of the integrated valve to one of the system supply or exhaust pipes, coupling the other integrated valve port to a heat pump; opening each isolation valve; testing the integrity of the couplings; assembling the insulating enclosure around the integrated valve .

[0031] The method thus obviates many on site assembly steps required as described in the prior art.

[0032] The method may further comprise the steps of providing a thermally insulating enclosure closely corresponding to the shape size and configuration of the integrated valve assembly and; fastening the enclosure around the integrated valve assembly. Brief description of figures

[0033] An integrated, insulated valve for heat pump systems and method of manufacture and installation will now be described by way of example only, with reference to the accompanying illustrative figures, in which: figure 1 is a prior art assembly of valve fixtures; figure 2 is a front elevation of a first embodiment of the integrated valve assembly of the present invention; figure 3 is a sectional elevation of the valve assembly of figure 2; figure 4 is a front elevation of the an insulating enclosure; figure 5 is a front sectional elevation of the insulating enclosure and enclosed integrated valve of figure 4; and figure 6 is a sectional view on the line l-l in figure 4. Detailed description of figures

[0034] An integrated valve has a unitary cast or moulded housing 15 providing a main passage 16 to facilitate the uninterrupted flow of water from an inlet port 17 to an outlet 31 10 25 port 18. The housing provides an isolation valve part which includes features to accommodate a ball (not shown) in a ball chamber 19. A spindle 20 passes through a spindle passage machined into the housing to facilitate rotation of the ball when the spindle head 21 is rotated. As is common the spindle head is threaded to receive a handle, however it may be convenient to provide a hex, socket or similar wrench fitting on the spindle head whereby a wrench can be used to rotate the ball and operate the isolation valve from open to closed. This obviates the necessity of accommodating the handle in the insulating enclosure.

[0035] K “separate” cap part 22 may be formed and fitted to the housing 15 to facilitate installation of the isolation valve components. The cap part includes an inlet port with internal threading to provide a female part of a compression fitting whereby the integrated valve can be joined to a 28mm circuit pipe of a heat pump installation in a manner known to the person skilled in the art.

[0036] Immediately downstream of the isolation valve part is a strain part. The strain part has a cylindrical sleeve 23 projecting down at an oblique angle from the main passage. The sleeve 23 is sized to receive a cylindrical and tubular strain 24. The main bore of the housing 15 is deformed from its cylindrical shape so that the internal surface of the housing meets a rim of the strain 24 whereby water moving through the main passage must pass through the holes formed in the strain 24. Particulate matter fouling the water passing through the main passage is thus forced into the open end of the strain and trapped.

[0037] The strain 24 is retained by a stop cock 25 screwed into a threaded opening of the sleeve 23 to normally seal the opening. The stop cock 25 provides a convenient means to drain the integrated valve when the strain needs to be serviced. The strain is serviced by removing the stopcock to facilitate removing the strain 24 and any captured fouling.

[0038] Downstream of the strain part is formed a thermostatic and vacuum brake part. Along this length of the housing a thermostatic port 26 is machined vertically up into the integrated valve housing 15 to receive a thermostatic assembly 27. Thermostatic assemblies are well known in the art and include a thermostatic element which, at low temperatures where freeing is a threat, opens a passage through the thermostatic 31 10 25 assembly to create a flow of water discouraging freezing as the water is drawn from the warm interior of the installation to the outside where the heat pump integrated valve is installed.

[0039] Opposite the thermostatic assembly a threaded port 28 is machined vertically down through the housing 15. The port 28 receives a vacuum breaker part 29.

[0040] Downstream of the thermostatic assembly and vacuum brake part is formed a conventional pipe coupling provided by internally threaded sleeve 30.

[0041] The integrated valve embodying the invention is based on coupling to a 28mm diameter pipe circuit as is the prior art valve shown in figure 1 and each are drawn to the same scale. As a result of the integration the length of the integrated valve B is shorter than the prior art valve length “A” by approximately 40%. There is also by comparison with the prior art assembly, a corresponding reduction in the mass of materials used, also the joining pipe lengths are obviated and the olives, nuts etc required to couple to the intervening pipe lengths are obviated.

[0042] Once installed an insulating enclosure shown in figures 4, 5 and 6 is assembled around the installed integrated valve. The enclosure is comprised of a bottom part 31 and a top part 32. Each part is moulded from an insulating expanded foam material.

[0043] Generally, the top part will be presented over the integrated valve and has a longitudinally extending channel 33 formed in a bottom face to accommodate the housing 15. An upwardly extending isolation valve formation cavity 34 projects up into the top part from the channel 33 to accommodate the corresponding formation of the isolation valve part and spindle. Downstream a vent assembly cavity 35 extends up from the channel 33 to accommodate the vent assembly 28. A vent passage 36 extends up from the top of the vent cavity and arcs over to reach an opening in the bottom face of the top part of the enclosure.

[0044] The channel 33 opens to a downstream side opening to accommodate connection to the heat pump.

[0045] The bottom part 31 has a channel 37 complementary to the channel 33 to accommodate the underside of the housing 15 and forms a passage in cooperation with the top part to accommodate a circuit pipe (not shown). A strain and stop cock na\ / i+\ / ic farmed nmiontinn dn\A / n frrxm the nhonnal ^"7 fr» anAnrrimndafa tho drain 31 10 25 and stop cock part. A thermostatic cavity 39 is formed descending from the channel 37 to accommodate the thermostatic assembly. The thermostatic cavity 39 is open at the bottom to allow liquid from the thermostatic assembly to discharge.

[0046] , A vent passage 40 is formed to descend from a top surface of the bottom part and to communicate with the vent passage 36 when the bottom part of the enclosure is assembled to the top part so that vapour or condensate from the vent assembly can discharge.

[0047] , The bottom surface of the top part 32 has shoulder formations 41 complementary to shoulder formations 42 formed on the top surface of the bottom part 31 where the bottom part and top part mate together. The shoulder surfaces are sized to form an interference press fit whereby the top and bottom parts of the enclosure are held together when assembled but can be manually pulled apart to expose the integrated valve for maintenance.

[0048] , If the integrated valve is installed in a situation where climate makes the thermostatic valve device undesirable it can readily be removed by unscrewing the thermostatic device from the fitting and substituting a plug.

Claims

1.An integrated insulated valve for use in heat pump installations comprising at least: an isolation valve part;a strain part;an antifreeze;and;a vacuum breaker partsaid isolation valve part, the strain part, the antifreeze and vacuum breaker part being factory integrated and provided with site couplings at an upstream port and a downstream port and a main passage extending between the upstream port and downstream port.2.A valve according to claim 1 comprising a single housing machined from a single brass casting having features into which each of an isolation valve, a strain assembly and drain cock, an antifreeze device and a vacuum breaker are installed.3.A valve according to claim 1 or 2 comprising a plug in place of the drain cock.4.A valve according to any one of the preceding claims wherein a cap part is irremovably assembled to the valve during manufacture to facilitate installation of the components of the isolation valve, said cap part including a pipe coupling to facilitate coupling the integrated valve to a pipe end.5.A valve according to any one of the preceding claims comprising a sleeve formation extending at an obtuse angle from a long axis of the housing whereby the housing accommodates a strain extending into the main passage to capture fouling.A valve according to claim 5 wherein the sleeve formation is threaded at a port distal from the main passage whereby one of a stop cock or plug is removably located to retain the strain.7.A valve according to any one of the preceding claims having a threaded port machined and receiving a thermostat device to control discharge of water from the main passage in response to ambient temperature approaching freezing.8.A valve according to any one of the preceding claims wherein a vacuum break port is machined into the housing and a vacuum break device is installed in the vacuum break port.9.A valve according to any one of the preceding claims wherein the housing is formed from multiple parts inseparably joined during manufacture.10.A valve according to any one of the preceding claims having a separable insulating enclosure.11.A valve according to claim 10 wherein the separable insulating enclosure is formed from two separable parts to be joined together around the integrated valve.12.A valve according to claim 11 where in the insulating enclosure parts are a top part and a bottom part.13.A valve according to one of claims 10 to 12 comprising a cavity to accommodate the vacuum break device said cavity communicating with an air passage whereby14.15.16.17.18.ambient air can be drawn to the vacuum break, anda thermostatic device cavity to accommodate the thermostatic device, said thermostatic device cavity communicating with a discharge passage to facilitate discharge of liquid from the thermostatic device.A valve according to any on of claims 11 to 13 wherein each part of the insulating enclosure is formed with a mating surface to mate with at least one other part of the insulating enclosure, said mating surface having engagement features to hold the enclosure parts together after manual assembly and enable manual disassembly for access to the integrated valve.A valve according to claim 14 wherein the engagement features are provided by shoulders which tightly press fit together.A method of fabricating an integrated valve assembly for use in a heat pump installation comprising:casting a housing with each of an isolation valve part, a strain part, an antifreeze part and vacuum break part;machining features into the housing to receive the components of; an isolation valve, a strain, an antifreeze device and a vacuum break;machining upstream and downstream coupling ports;installing each of the components of an isolation valve, a strain, an antifreeze device and a vacuum break device;.A method according to claim 16 comprising moulding an insulating enclosure to fit around the integrated valve.A method according to claim 17 comprising moulding the enclosure from an exoanded foam in two carts adaoted to fit around and therebv enclose theintegrated valve, said enclosure having cavities to accommodate, respectively, the isolation valve, the strain, the thermostatic device and the vacuum break, and comprising a vent passage communicating with the vacuum break cavity and said thermostatic device cavity communicating with a discharge passage to facilitate discharge of liquid from the thermostatic device.19.A method of installing an insulated integrated valve assembly according to any one of claims 1 to 15 comprising:coupling a port of the integrated valve to one of the system supply or exhaust pipes,coupling the other integrated valve port to a heat pump;opening the or each isolation valve;testing the integrity of the couplings;assembling the insulating enclosure around the integrated valve.20.A method according to claim 19 comprising pressing the parts of the insulating enclosure together to assemble the insulating enclosure.

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