System separator unit

Abstract

System separator unit (1) for preventing a backflow of liquid from an output liquid system into an input liquid system, comprising a one-piece, preferably metallic, system housing (10) which has an inlet connection (11) coaxially on a housing longitudinal axis (L) and an outlet connection (12) in flow connection therewith via a through-channel arrangement, as well as further connection points (16, 17) located in a common central longitudinal plane at least for a pressure reducer (30) and a relief valve (45) and receptacles for an input backflow preventer (40) and an output backflow preventer (42), wherein - an inlet chamber (50) is formed in front of the inlet non-return valve (40), at which the connection point (16) for the pressure reducer (30) and the connection point (17) for the relief valve (45) are arranged, - the connection point (16) for the pressure reducer (30) is designed as a connection piece with a first connection axis inclined at an angle of between 30° and 80° to the longitudinal axis (L) of the housing towards the inlet side, and the pressure reducer (30) is screwed or can be screwed coaxially into the connection piece, - the through-channel arrangement is guided from the inlet connection (11) through a connecting opening of the system housing (10) in the region of the connecting piece, an inlet opening which is aligned with this when the pressure reducer (30) is inserted and which is present laterally with respect to the first connection axis, and an outlet opening of the pressure reducer (30) which is arranged in the front region downstream of a pressure reducer valve unit relative to the housing longitudinal axis (L), and opens into the inlet chamber (50) in front of the inlet non-return valve (40), - a central chamber (51) is formed between the inlet non-return valve (40) and the outlet non-return valve (42), which is fluidically connected to the spring-loaded relief valve (45) via a connecting connection (18) in order to open an outlet to the atmosphere when a differential pressure between the pressure in the inlet chamber (50) and the central chamber (51) falls below a defined limit value, - the connection point (17) for the relief valve (45) is designed as a receiving nozzle with a nozzle axis directed at right angles to the longitudinal axis (L) of the housing and extending through the inlet chamber (50), - the connection point (16) of the pressure reducer (30) and the connection point (17) of the relief valve (45) are arranged diametrically opposite each other with or without offset in the axial direction on the system housing (10) and - the inlet non-return valve (40) and the outlet non-return valve (42) are inserted coaxially to the longitudinal axis (L) of the housing in the system housing (10), wherein access for installing and removing the inlet non-return valve (40) and the outlet non-return valve (42) is provided via an access opening through the wall of the system housing (10) in the region of the central chamber (51) transversely to the housing axis (L).

Description

[0001] The invention relates to a system separator unit for preventing a backflow of liquid from an output liquid system into an input liquid system, comprising a one-piece, preferably metallic, system housing, which has an inlet connection coaxially on a housing longitudinal axis and an outlet connection in flow connection with the latter via a through-channel arrangement, as well as further connection points for at least a pressure reducer and a relief valve and receptacles for an input backflow preventer and an output backflow preventer, wherein an inlet chamber is formed upstream of the input backflow preventer, at which the connection point for the pressure reducer and the connection point for the relief valve are arranged, and a middle chamber is formed between the input backflow preventer and the output backflow preventer,which is fluidically connected to the spring-loaded relief valve via a connecting port in order to open a drain to the atmosphere when a differential pressure between the pressure in the inlet chamber and the middle chamber falls below a defined limit.

[0002] A system separator unit of this type is described in EP 1 452 652 B1. In this known system separator unit, a pressure reducer is connected perpendicular to the longitudinal axis of the housing via respective connection points to a system housing with an inlet connection and an outlet connection located on a common longitudinal axis of the housing. A relief valve is connected diagonally to the longitudinal axis of the housing and has an inlet chamber and a middle chamber between an inlet check valve and an outlet check valve in a through-channel arrangement. The relief valve is provided with an outlet to the atmosphere to prevent backflow of liquid from an outlet liquid system connected to the outlet into an input liquid system connected to the inlet. Test connections on the housing are closed by plugs. A pressure gauge is connected to an outlet channel via a test connection.A shut-off valve is connected to the inlet port. The upstream and downstream check valves and the relief valve are combined in a pipe separator cartridge assembly, which is inserted into a receiving bore aligned obliquely to the longitudinal axis of the housing.

[0003] DE 28 54 003 A1 discloses a system separator unit with a housing having an inlet connection and an outlet connection coaxial with the housing's longitudinal axis, as well as an inlet check valve located between an inlet chamber and a central chamber, and an outlet check valve located between the central chamber and the outlet. The two check valves are arranged coaxially with the housing's longitudinal axis and are accessible for installation and removal via a cover-covered access opening in the central chamber. A relief valve with a connected outlet channel is arranged in a housing section formed laterally of the central chamber.

[0004] A system separator unit with a similar structure to the one mentioned above can be found in DE 29 30 819 C2, in which retaining rings are used as holding means for the backflow preventers.

[0005] Another system separator unit with an inlet non-return valve and an outlet non-return valve arranged coaxially to a housing longitudinal axis is also shown in FR 2 544 832 A1.

[0006] In another system separator unit presented in US 4,945,940 A, shut-off units are coaxially connected on the inlet and outlet sides on a common longitudinal axis to a central section of the system housing. In the central system housing section, a bulged central chamber is arranged between an inlet check valve and an outlet check valve. The central chamber has a connection with a relief valve, which opens an outlet to the atmosphere when the differential pressure between the pressure in an inlet chamber and the middle chamber drops below a pressure threshold. For this purpose, the relief valve is in fluid communication with the inlet chamber via a line connection. A pressure reducer is not present.

[0007] Further functionally similar system separator units of this type are shown in EP 1 950 354 B1, DE 10 2004 063 747 B4 and EP 1 022 398 B1.

[0008] The present invention is based on the object of providing a system separator unit of the type mentioned above, which is flow-optimized and offers user-friendly installation options with a compact, clear design.

[0009] This object is achieved in a system separator unit with the features of claim 1. In conjunction with the further features, it is further provided that the inlet backflow preventer and the outlet backflow preventer are installed coaxially to the longitudinal axis of the housing in the system housing, wherein a common access for installing and removing the inlet backflow preventer and the outlet backflow preventer is formed via an access or assembly opening through the wall of the system housing in the region of the central chamber transversely to the longitudinal axis of the housing or at right angles to it. The access opening is advantageously formed in a connection piece that can be closed by means of a sealing plug. This design results in a compact housing with a clear and flow-optimized arrangement of the components integrated therein and connected to it, with user-friendly assembly options and a compact design.This makes it easy to install and remove the backflow preventers individually, even when the system separator unit is installed.

[0010] The advantageous design according to the invention for the structure and function consists in that the connection point for the pressure reducer is designed as a connection piece with a first connection axis inclined at an angle between 30° and 80° or 60° to the longitudinal axis of the housing on the inlet side and that the pressure reducer is screwed or can be screwed coaxially into the connection piece, wherein the through-channel arrangement is guided from the inlet connection through a connecting opening of the system housing in the area of the connection piece, an inlet opening which is aligned with this when the pressure reducer is inserted and is present laterally with respect to the first connection axis, and an outlet opening of the pressure reducer which is arranged in the front area lying downstream of a pressure reducer valve unit in relation to the longitudinal axis of the housing and opens into the inlet chamber in front of the inlet non-return valve.Furthermore, the through-duct arrangement then runs through the two backflow preventers to the outlet connection.

[0011] The fact that the connection point for the relief valve is designed as a receiving nozzle with a nozzle axis directed at right angles to the longitudinal axis of the housing and extending through the inlet chamber contributes to a compact design with good function.

[0012] A further measure according to the invention for a compact design and good function consists in that the connection point of the pressure reducer and the connection point of the relief valve are arranged diametrically opposite each other with or without offset in the axial direction on the system housing.

[0013] A user-friendly design consists in that in the area of the middle chamber, via a further connection point, in particular also designed as a connection piece, a pressure gauge for reading a set or adjustable output pressure of the output fluid system is arranged, in particular circumferentially on the same side as the connection point of the pressure reducer.

[0014] Further advantageous measures for a user-friendly design consist in the fact that a test connection for an upstream pressure is / are present on the system housing in the area of the inlet chamber, a test connection for the intermediate pressure in the area of the middle chamber and / or a test connection for the outlet pressure prevailing on the side of the outlet fluid system in the area downstream of the outlet non-return valve.

[0015] For maintenance and testing purposes, it is advantageous that the test connections are closed or closable with a respective sealing plug, in particular made of plastic or metal.

[0016] Installation and maintenance are also facilitated by the fact that the pressure gauge can be connected or is connected to the medium pressure test connection, particularly via a plug designed as an adapter with a connection thread for a counter thread of the pressure gauge, which can be screwed into the relevant connection point. The pressure read on the pressure gauge thus corresponds (except for a negligible, defined pressure difference caused by the outlet non-return valve) to the pressure in the outlet fluid system.

[0017] Further expedient alternative embodiments are obtained in that a shut-off valve with a handle can be connected or is connected to the inlet connection or in that a shut-off valve is installed in the area of the inlet connection and can be operated via a handle arranged on the outside of the inlet connection.

[0018] Advantages for assembly and maintenance also arise from the fact that the inlet backflow preventer and the outlet backflow preventer are held in position by means of different holding means, wherein the design is particularly carried out in such a way that the inlet backflow preventer is securely held in position in the associated receptacle by means of a snap-in connection with snap-in lugs and the outlet backflow preventer is securely held in position in the associated receptacle by means of a retaining ring or that conversely the inlet backflow preventer is held by means of a retaining ring and the outlet backflow preventer is held by means of a snap-in connection.

[0019] Another advantageous design for design and user-friendly installation is that the connection point for the pressure gauge or the medium-pressure test connection is used as the access point for installing and removing the backflow preventer. This design eliminates the need for a separate access point for installing and removing the backflow preventer.

[0020] The invention is explained in more detail below using an exemplary embodiment with reference to the drawing. In the drawings: Fig. 1 a first embodiment of a system separator unit in longitudinal section with components connected to a system housing and a separate, connectable shut-off valve and Fig. 2 in partial images a) and b) a further embodiment of a system separator unit with connection points arranged on a system housing for connecting components and with a shut-off valve accommodated in the system housing in longitudinal section (partial image a)) and in a view from the outlet side (partial image b)).

[0021] One in the Fig. 1 and Fig. The system separator unit 1 shown in Figure 2 comprises a system housing 10 with an inlet connection 11 and an outlet connection 12 formed integrally coaxially with a housing longitudinal axis L. Several connection points for components that are removably connected or connectable thereto are provided on the system housing, which include a connection point 16 for a pressure reducer 30 and a connection point 17 for a relief valve 45. Furthermore, closable connection points 13, 14, 15 are provided for a test connection for measuring an upstream pressure in an inlet chamber 50, for a test connection for measuring an intermediate pressure in a middle chamber 51, and for a test connection for measuring an outlet pressure in an outlet chamber 52.

[0022] The Fig. 1 and Fig. The system separator units 1 shown in Figure 2 are used to prevent a backflow of liquid from an output liquid system into an input liquid system, such as for supplying water from a drinking water system into a heating system and to prevent a backflow of contaminated water into the drinking water system if, for example, the pressure in the drinking water system collapses.

[0023] According to Fig. 1, a shut-off valve 60 provided with a thread adapted thereto can be connected to the inlet connection 11 via a connection thread (in this case an external thread), which shut-off valve has a shut-off valve unit adjustable by means of a handle 61 for opening and closing a passage from the input liquid system to the output liquid system.

[0024] In the Fig. In the embodiment shown in Figure 1, a sealing plug 20 is screwed into a connection piece at the connection point 14 for the medium pressure test connection in the area of the middle chamber 51 on the system housing 10. The plug has an internal thread on the outlet side, via which a pressure gauge 32 is connected by means of a matched counter-thread. This pressure gauge 32 can be used to read the pressure prevailing in the middle chamber or a set pressure of the outlet fluid system, for example, a heating system. The pressure in the outlet chamber 52 is thus identical to the pressure of the outlet fluid system set via the pressure reducer, except for a small, negligible pressure difference caused by an outlet non-return valve 42.

[0025] As the Fig. 1 and Fig. 2 further shows, the middle chamber 51 lies between an inlet non-return valve 40 and the outlet non-return valve 42. From the middle chamber 51, a fluid-conducting connection is formed integrally on the system housing via a connecting port 18 to the relief valve 45. On the inlet side, the relief valve 45 is fluid-conductingly connected to the inlet chamber 50 for pressurizing with the pressure in the inlet chamber 50. The relief valve 45 is inserted into the connection point 17, which is designed as a receiving nozzle integrally formed on the system housing 10, and is secured in position by means of a retaining ring 46.When the differential pressure between the inlet chamber 50 and the middle chamber 51 falls below a defined limit, the relief valve 45 opens to the atmosphere via the middle chamber 51 and the connecting port 18, so that no contaminated water from the outlet fluid system enters the inlet fluid system.

[0026] The inlet backflow preventer 40, like the outlet backflow preventer 42, is installed in the through-channel arrangement coaxially to the housing's longitudinal axis L. The inlet backflow preventer 40 is securely held in position in the through-channel arrangement or a bore of the system housing 10 in a receptacle formed therein by means of a locking lug 41 that engages in an associated recess in the inner wall surface of the system housing 10 or engages behind a locking shoulder. The outlet backflow preventer 42 is also securely held in position in a receptacle of the through-channel arrangement or a bore in the system housing 10, but is secured by means of a retaining ring 43 that engages in a circumferential groove or is supported on a circumferential shoulder.The inlet backflow preventer 40 and the outlet backflow preventer 42 can be easily distinguished and installed thanks to the different holding mechanisms.

[0027] The connection points 13, 14, 15 of the test connections are closed by means of plugs, e.g. made of plastic or metal, which can be removed for testing purposes, e.g. screwed into the respective connection points.

[0028] How Fig. 1 and Fig. 2, the connection points of the various components lie in a common central longitudinal plane, whereby the connection point 16 of the pressure reducer 30 and the connection point 17 of the relief valve 45 can be arranged diametrically opposite each other, but axially offset or unoffset from each other, and are located in the region of the inlet chamber 50 of the system housing 10. The connection point 14 of the pressure gauge 32 is located in the present case on the same side of the housing longitudinal axis L as the connection point 16 of the pressure reducer 30. The axis of the connection piece of the pressure reducer 30 is inclined relative to the housing longitudinal axis L towards the inlet side or towards the inlet connection 11, e.g. in an angular range between 20° and 90°, for example between 30° and 60°.The through-channel arrangement leads from the inlet connection 11 through a lateral connection opening of the system housing 10 in the region of the connection piece, into an inlet opening which is aligned with this when the pressure reducer is inserted, and from there through a pressure reducer valve unit present in the pressure reducer 30 through an outlet opening present on the downstream side of the pressure reducer 30 into the inlet chamber 50. In this way, the pressure in the inlet chamber 50 upstream of the system separator is constantly regulated by the pressure reducer 30 in order to compensate for inlet-side pressure fluctuations of the inlet fluid system.

[0029] A channel from connection point 13 for the test connection of the pre-pressure is also required in the design according to Fig. 1 is inclined at an angle relative to the longitudinal axis L of the housing, e.g. in an angle range between 20° and 80° towards the inlet side, and is located opposite the connection point of the pressure reducer 20 towards the inlet side in front of the connection point of the relief valve 45 arranged at a right angle to the longitudinal axis L of the housing.

[0030] The pressure reducer 30 arranged upstream of the inlet non-return valve 40 thus also keeps the outlet pressure constant during normal operation.

[0031] As from Fig. 1 and also from Fig. 2 (partial image a)), the clear width of the opening of the connection piece at the connection point 14 for the medium pressure test connection or the pressure gauge 32 in the area of the middle chamber 51 is larger than the through-section of the through-channel arrangement in the system housing 10, at least in this area. This advantageously provides access to the inlet backflow preventer 40 and the outlet backflow preventer 42, so that these can be removed and installed without removing the entire system separator unit 1 from a closed line arrangement, thanks to the design and arrangement of their fastening means, the locking lug 41 and the retaining ring 43, respectively. The other components mentioned, pressure reducer 30, relief valve 45, pressure gauge 32 and sealing plug, are also easily accessible and can be installed and removed without dismantling the entire system separator unit 1.

[0032] The execution according to Fig. 2 differs from that according to Fig. 1 by the arrangement of the shut-off valve 60, which in the design according to Fig. 2 is inserted into a receptacle integrally integrated in the inlet area of the system housing 10. A handle 61 with a connecting piece is guided through a lateral opening arranged in the housing wall in order to actuate a shut-off mechanism of the shut-off valve 60.

[0033] In addition, when executing according to Fig. 2 in contrast to the execution according to Fig. 1 the test connection(s) 13 for measuring the inlet pressure are arranged in a cross-sectional plane offset by 90° to the connection point 16 of the pressure reducer 30 or the connection point 17 of the relief valve 35, in this case laterally, as can be seen from the partial figure b) of the Fig. 2. This contributes to a compact design of the system separator unit 1, even with the shut-off valve 60 integrated into the system housing 10, while still being easily accessible.

[0034] The system separator unit 1 according to the Fig. 1 and Fig.2 provides reliable function during water make-up, e.g., in a heating system, and to prevent backflow. The relief valve 45 is acted upon in the closing direction by the pressure in the inlet chamber 50 (inlet pressure), thus closing it off to the atmosphere. If the pressure in the inlet chamber continues to rise, the inlet backflow preventer 40 and the outlet backflow preventer 42 open, and the water flows to the outlet chamber 52. The pressure in the middle chamber 51 and a spring of the drain valve unit arranged in the relief valve 45 now act on the relief valve 45 in the opening direction. The pressure in the middle chamber 51 is lower than the inlet pressure due to the spring-loaded inlet backflow preventer 40. If the differential pressure between the inlet pressure and the pressure in the middle chamber 51 falls below a defined limit, the spring-loaded relief valve 45 opens to the atmosphere and the middle chamber 51 is ventilated.The correct function of the system separator unit 1 can be checked via the test connections at connection points 13, 14, 15.

Claims

[1] System separator unit (1) for preventing a backflow of liquid from an output liquid system into an input liquid system, comprising a one-piece, preferably metallic, system housing (10) which has an inlet connection (11) coaxially on a housing longitudinal axis (L) and an outlet connection (12) in flow connection therewith via a through-channel arrangement, as well as further connection points (16, 17) located in a common central longitudinal plane at least for a pressure reducer (30) and a relief valve (45) and receptacles for an input backflow preventer (40) and an output backflow preventer (42), wherein - an inlet chamber (50) is formed in front of the inlet non-return valve (40), at which the connection point (16) for the pressure reducer (30) and the connection point (17) for the relief valve (45) are arranged, - the connection point (16) for the pressure reducer (30) is designed as a connection piece with a first connection axis inclined at an angle of between 30° and 80° to the longitudinal axis (L) of the housing towards the inlet side, and the pressure reducer (30) is screwed or can be screwed coaxially into the connection piece, - the through-channel arrangement is guided from the inlet connection (11) through a connecting opening of the system housing (10) in the region of the connecting piece, an inlet opening which is aligned with this when the pressure reducer (30) is inserted and which is present laterally with respect to the first connection axis, and an outlet opening of the pressure reducer (30) which is arranged in the front region downstream of a pressure reducer valve unit relative to the housing longitudinal axis (L), and opens into the inlet chamber (50) in front of the inlet non-return valve (40), - a central chamber (51) is formed between the inlet non-return valve (40) and the outlet non-return valve (42), which is fluidically connected to the spring-loaded relief valve (45) via a connecting connection (18) in order to open an outlet to the atmosphere when a differential pressure between the pressure in the inlet chamber (50) and the middle chamber (51) falls below a defined limit value, - the connection point (17) for the relief valve (45) is designed as a receiving nozzle with a nozzle axis directed at right angles to the longitudinal axis (L) of the housing and extending through the inlet chamber (50), - the connection point (16) of the pressure reducer (30) and the connection point (17) of the relief valve (45) are arranged diametrically opposite each other with or without offset in the axial direction on the system housing (10) and - the inlet non-return valve (40) and the outlet non-return valve (42) are inserted coaxially to the housing longitudinal axis (L) in the system housing (10), wherein access for installing and removing the inlet non-return valve (40) and the outlet non-return valve (42) is formed via an access opening through the wall of the system housing (10) in the region of the central chamber (51) transversely to the housing axis (L). [2] System separator unit (1) according to claim 1, characterized bythat a respective connection point (13, 14, 15) is / are present on the system housing (10), namely in the region of the inlet chamber (50) a connection point (13) for a test connection for a pre-pressure, in the region of the middle chamber (51) a further connection point (14) for a test connection for the medium pressure and / or in the region downstream of the outlet non-return valve (42) a connection point (15) for a test connection for the outlet pressure prevailing on the side of the outlet fluid system, wherein the connection points (13, 14, 15) are designed in particular as connection pieces. [3] System separator unit (1) according to claim 2, characterized by that the connection points (13, 14, 15) for the test connections are closed or closable with a respective sealing plug, in particular made of plastic or metal. [4] System separator unit (1) according to claim 2 or 3, characterized bythat a pressure gauge (32) can be connected or is connected to the further connection point (14) for the test connection for the medium pressure, in particular via a sealing plug (20) designed as an adapter piece with a connection thread for a counter thread of the pressure gauge (32) and which can be screwed into the relevant connection point (14). [5] System separator unit (1) according to one of the preceding claims, characterized by , that a shut-off valve (60) with a handle can be connected or is connected to the inlet connection (11) or that a shut-off valve (60) is installed in the area of the inlet connection (11), which can be actuated via a handle (61) arranged on the outside of the inlet connection (11) [6] System separator unit (1) according to one of the preceding claims, characterized by , that the inlet non-return valve (40) and the outlet non-return valve (42) are held in position by means of different holding means, The training is carried out in particular in such a way that the inlet non-return valve (40) is securely held in position in the associated receptacle by means of a locking connection with locking lugs (41) and the outlet non-return valve (42) is securely held in position in the associated receptacle by means of a retaining ring (43) or that, conversely, the inlet non-return valve (40) is held by means of a retaining ring (43) and the outlet non-return valve (42) is held by means of a snap-in connection. [7] System separator unit (1) according to one of claims 2 to 6 as far as related to claim 4, characterized bythat the connection point (14) for the pressure gauge (32), i.e. for the medium pressure test connection, is used as access for the installation and removal of the inlet non-return valve (40) and the outlet non-return valve (42).

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