GB2384545A

GB2384545A - Radiator valve and valve seat closure line profile

Info

Publication number: GB2384545A
Application number: GB0229590A
Authority: GB
Inventors: Fester Garm
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 2001-12-20
Filing date: 2002-12-19
Publication date: 2003-07-30
Anticipated expiration: 2022-12-19
Also published as: FR2834036B1; FR2834036A1; GB0229590D0; CN1427195A; RU2245473C2; PL357542A1; GB2384545B; PL205100B1; DE10162604A1; CZ20024218A3; CN1231689C; DE10162604B4

Abstract

A radiator valve with a valve seat surrounding an opening (19) which can be closed by a valve member that, in a closed position, bears on the valve seat along a closure line (20-22) which has at least one section (21) which is directed inwardly into the opening (19), and on the outside along the closure line (20-22) a free space (23) is provided in the form of the outer sides (23) of the closure line being cut away or sloping away to the base (24). The profile of the closure line may be star-shaped, and may be formed on the valve member of the valve seat (10), and may be concave relative to its cooperating sealing surface.

Description

- 1 - Radiator valve This invention concerns a radiator valve having a 5

valve seat surrounding an opening closable by a valve element, which element, in a closed position, abuts on the valve seat along a closure line.

Such radiator valves are commonly known, and used in or on most radiators. The valve element, which is also 10 called (in Germany at least) "valve cones, is biased by a spring in the opening direction, that is, away from the valve seat. An operating device, usually a thermostatic valve cap, exerts a closing force on the valve element in dependence on an ambient temperature, said closing force 15 causing the valve element to bear on the valve seat when required to do so. Thus, further inflow of heating fluid into the radiator is blocked. The bearing of the valve element on the valve seat occurs along a closure line.

This closure line is not a line in the exact mathematical 20 sense but is usually a relatively narrow surface area, at which contact between the valve element and the valve seat occurs. The outer dimensions such a radiator valve can have are limited. Here, for example, the dimensions for a 25 connection to the radiator and also the space available near the radiator are important. The result is that the outer diameter of the valve seat cannot exceed a predetermined size. The stroke of the valve element in relation to the valve seat is also limited.

30 The invention is based on the problem of permitting a large flow with unchanged outer dimensions.

The present invention provides a radiator valve with a valve seat surrounding an opening closable by a valve element that, in a closed position, bears on the valve seat along a closure line, wherein the closure line has at 5 least one section which is directed inwardly into the opening, and wherein on the outside along the closure line a free space is provided, even in the closed position of the valve element.

With a radiator valve as mentioned in the lo introduction, the abovementioned problem is solved in

that the closure line has the at least one section which is directed inwardly into the opening, and in that on the outside along the closure line the free space is provided, even in the closed position of the valve element.

15 With this construction, the closure line is enlarged compared with a simple circular line surrounding the opening. Thus, during lifting of the valve element away from the valve seat, a larger cross-sectional area is available for the flow of heating fluid. This 20 presupposes, however, that on both sides of the closure line there is a free space through which the heating fluid can flow unthrottled. When this free space is already available in the closed position, it continues to exist when the valve element is lifted a small distance away 25 from the valve seat. In fact, enlargement of the closure line causes an enlargement of the outflow cross-section, through which the fluid can pass unthrottled.

Preferably, more sections are provided which are distributed uniformly around the circumference of the 30 opening. The greater the number of sections provided, the longer does the closure line become, that is, the larger does the flow cross-section become, through which the

fluid can flow, when the valve element is lifted from the valve seat. The uniform distribution ensures a certain symmetry so that the valve element is evenly loaded when the heat-carrying medium is flowing through. This reduces 5 any tendency of the valve element to oscillate.

Preferably, the section opposite to a plane that is defined by radially outermost circumferential sections of the opening is sloped away from the valve element. The closure line is therefore, as it were, concavely sloped 10 from the outside inwards. The valve element then undergoes a little convex deformation in the closing state. This construction has the advantage that, when the valve opens, that is, when the valve element lifts from the valve seat, a small gap will occur initially in the 15 middle, that is, at the radially inner sections of closure line, between the valve element and the valve seat, through which gap a small fluid flow is already possible.

As the closing pressure on the valve element decreases, this gap will become larger, until finally the valve 20 element has lifted away completely from the valve seat.

With this opening behaviour, a very sensitive control of the flow of heatcarrying medium through the valve is possible at the start of the opening procedure.

It is particularly preferred that the section has a 25 maximum distance from the plane of about 0.1 to 0.2 mm.

Such a small lowering of the inner ends of the sections in relation to their outer ends can easily be accommodated by deformation of the valve element. However, it permits the very sensitive control mentioned above of the heat 30 carrying medium through the valve.

Preferably, the valve seat is formed on a seat element, and the free space is formed by a clearance space

- 4 in the seat element. This construction has the advantage that a conventional valve element with a virtually circular bearing area can be used. The contact between the valve seat and this bearing area of the valve element 5 then occurs along the closure line, which is no longer limited to a circular area at the edge of the valve element, but also acts upon radially further inward surface areas of the valve element. The fact that clearance space is provided beyond the closure line, that 10 is, where the sections of the closure line extend radially inward, ensures that the required flow cross-section is available immediately after the valve element has lifted away from the valve seat, said cross-section permitting the larger flow and thus ensuring the larger capacity of 15 the valve.

Preferably, the clearance space has a sloped base.

This construction has mechanical advantages. The seat element receiving the valve seat becomes mechanically more stable. The closure line no longer extends just on the 20 upper edge of a "wall,', but is reliably supported by body parts of the seat element.

In this connection, it is particularly preferred that from the outside the base merges into the closure line.

Thus, the closure line is therefore adequately supported 25 over practically its whole length. Additionally, the -

sloped base, merging from the outside into the closure line, ensures a gentle transition for the fluid as it flows over the closure line. This leads to quiet operation of the valve. This low-noise characteristic of 30 the valve occurs already as a positive side effect of the lengthening of the closure line and the associated smaller pressure drop (compared with a conventional valve having

the same stroke), but it is further improved by the design of the base.

In this connection, it is preferred that the base has an angle of inclination in the range from 30 to 90 . On 5 the one hand, this angle of inclination ensures an adequate mechanical stability; on the other hand it permits a relatively quiet flow through the valve.

According to an alternative or additional feature, provision may be made for the free space to be formed in 10 the valve element and for the valve element to be non-

rotatably located in relation to the valve seat. When the valve element is mounted locked against rotation in relation to the valve seat, the clearance space in the valve element can be provided in such a way as to 15 correspond to the path of the closure line, that is, that also in the radially inwardly directed sections of the closure line sufficient free space is always available beyond the closure line, through which free space the heat carrying fluid can flow.

20 Preferably, the closure line is a star-shaped. With a star-shape, a relatively long closure line can be provided in a relatively small area.

In a preferred embodiment, the valve element has an adjustable stroke limitation. With the stroke limitation 25 presetting of the maximum flow quantity of heat carrying fluid through the valve is possible. For that purpose, it is known to use an "apron", which is arranged in the housing of the valve with a variable overlap to a discharge opening. Rotating this apron changes the 30 discharge cross-section. However, in connection with the extended closure line this construction does not always have the desired effect. Particularly, uneven loads on

the valve element may occur. These disadvantages are avoided by using a stroke limitation for the valve element. 5 Radiator valves constructed in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a schematic sectional view through a 10 radiator valve embodying the invention; Fig. 2 is a top view of a valve seat of the valve; 15 Fig. 3 is a section through the seat element corresponding to the section line III-III marked in Fig. 2; Fig. 4 is a sectional view through a modified 20 embodiment; Fig. 5 is a plan view of a valve seat with a valve element; 25 Fig. 6 is a further example of a valve seat; and Fig. 7 is a fourth example of a valve seat.

30 Referring to the accompanying drawings,-a radiator valve 1 shown in Fig. 1 has a housing 2, into which a valve insert 3 has been screwed. The valve insert 3 has a

valve spindle 4 carrying at its one end a valve element 5.

The valve element 5 is made of an elastomeric material and is supported by a supporting disc 6. The valve element 5 is substantially in the form of a short cylinder.

5 The valve spindle 4 is activated by an activating pin 7, which is guided through a stuffing box 8. The activating pin 7 acts upon the valve spindle 4 against the force of an opening spring 9.

The valve element 5 co-operates with a valve seat 10, 10 which is formed on a seat element 11. In Fig. 1, the seat element 11 is shown in two different versions. In the left half of Fig. 1, the seat element 11 is connected with the valve insert 3 by means of a flanged connection 12, the valve element 3 having an extension 13, in which in 15 turn a number of openings 14 are arranged, which permit the passage of heat carrying fluid from the valve seat to an outlet chamber 15.

The seat element 11 in turn is attached to a connector 16. On the end facing the connector, the seat 20 element has an O-ring 17, which is arranged in an inner groove 18 on the seat element 11.

The example of a valve seat 11 shown in the right half of Fig. 1 is also held by a flanged connection 12 of the extension 13 of the valve insert 3. Here, however, 25 the flanged connection 12 also holds the O-ring 17, which seals the connection to the connector 16. In this example, the connector 16 is somewhat longer.

As can be seen from Fig. 2, the valve seat 10 has a special shape. The valve seat 10 surrounds an opening 19, 30 through which the heat-carrying medium can escape-from the connector 16 into the outlet chamber 15, when the valve element 5 is lifted from the valve seat 10. This opening

- 8 has a largest diameter D, which is limited by the overall dimensions of the radiator valve 1.

On this largest diameter D, sections 20 of a closure line of the valve seat 10 are arranged, on which sections 5 the valve element 5 bears, when the radiator valve 1 is closed. Sections 21 extend from these sections 20, extending in this case as radial tongues inwardly into the opening 19. Two of such sections 21 are connected by sections 22, which are arranged on a substantially smaller 10 diameter.

The closure line, which is formed by the sections 20, 21, 22 thus has a meandering, zigzag or star-shaped path.

It is thus substantially longer than a closure line that is merely formed by a circular line of diameter D. 15 The inside of the closure line 20-22 bounds the opening 19.

On the outside of the closure line 20-22, a free space is provided all round, which is formed in the seat element 11. This free space 23 can be seen in Fig. 3.

20 On its left side as seen in Fig. 3, the seat element 11 carries the valve seat 10. Between sections 21 on the outside, clearance spaces are provided, which form the free space 23. These openings have a base 24, which is sloped by an angle of inclination in the range from 30 to 25 90 . Strictly speaking, there is no base in the last case. The base 24 merges into the valve seat 10, that is, at the radially inner side each free space 23 has the smallest height. However, this height increases radially outwardly. 30 -The fluid that flows from the connector 16 into the outlet chamber 15 is now throttled by the co-operation of the valve element 5 with the closure line 20-22 of the

/ ' - 9 - valve seat 10, that is, the resistance is determined exclusively by the distance between the valve element 5 and the valve seat 10. Fluid leaving the connector 16 through the sections 20 is able to flow away, uninfluenced 5 by the seat element 11, into the outlet chamber 15. Fluid flowing via the sections 21 over the closure line can also flow unobstructed into the free space 23. This applies even to areas located radially further inwards, as the free space 23 with its sloped base 24 presents no 10 significant additional throttling resistance. Also in the case of sections 22 there is practically no additional throttling caused by a possibly too small distance between the valve element 5 and the seat element 11. If additional throttling nevertheless occurs here, it is not 15 critical, as the sum of the lengths of the sections 22 compared with the length of the closure line 20-22 is relatively small.

When lifting the valve element 5 from the valve seat 10, the relatively long length of the closure line 20-22 20 results in a correspondingly large opening, through which the fluid can pass. The size of the opening corresponds to the stroke (distance between valve element 5 and valve seat 10) multiplied by the length of the closure line 20-

22. A correspondingly large closure line 20-22 also 25 provides a correspondingly large opening for the passage of heat carrying medium.

In the valve insert 3, there is arranged a stop 25, whose axial position can be changed by turning it in the valve insert 3. For this purpose, a thread 26 is 30 provided. The stop 25 forms a stroke limitation for the valve element 5. By this means, the maximum flow rate through the valve can be preset. For turning the stop 25

- 10 in the valve insert 3, a torque-transmitting element 27 is provided, which can be turned by means of a control 28.

With the embodiment shown, flow rates of the order of magnitude of 1000 to 1500 l/h are possible. The much 5 increased length of the closure line 20-22 is associated with a capacity increase of the valve of approximately 50% compared with a circular shape of the closure line with the same largest diameter D. Figs. 4 and 5 show a modified example of a seat 10 element 11'. Firstly, the seat element 11' has on its outside a circumferential groove 18', in which an O-ring can be mounted to provide a seal between the seat element 11' and a pipe connector, when the seat element 11' is inserted in the pipe connector.

15 Furthermore, the upper side of the seat element 11', which forms the valve seat 10, is planar. Here too, however, a relatively long closure line 20-22 is formed in that the opening 19 is bounded by the star-shaped path of the closure line. In order to provide the required free 20 space 23' here, the valve element 5 has a shape that corresponds to the shape of the opening 19, the valve element 5 being, of course, somewhat larger in order to be able to engage the valve seat 10'. Additionally, the valve element 5' has a spindle 4' with an anti-rotation 25 means 29, so that the valve element 5' is non-rotatably held in relation to the seat element 11'.

Figs. 6 and 7 show other shapes of closure line 30 and 31, respectively. In all cases, the opening 19 is surrounded by a relatively long closure line 30, 31, so 30 that with-this construction the radiator valve has a very large capacity.

- 11 In such a radiator valve 1, a relatively small stroke (or lift height) of the valve element 5 is sufficient, when it is desired to achieve the same flow rates as with conventional valves. For the same stroke, a substantially 5 larger flow rate is obtained. For a given flow rate, the valve could be made smaller.

The fact that a relatively long closure line 20-22 is available makes a greater pressure drop across the valve permissible. The thermostatic elements, which are 10 normally used for controlling such a valve, have a limited force. With a larger opening 19, a larger pressure drop is not permissible, as the thermostatic element would not be able to provide the force required to close the valve element 5. When, however, this area 19 is reduced and at 15 the same time the closure line 20-22 is lengthened, a greater pressure drop can be permitted.

The fact that the closure line 20-22 is longer also has an influence on the outlet flow velocity of the medium (which will usually be water) through the valve. This has 20 a positive effect on the noise level of the valve.

Furthermore, an additional advantage occurs: the relatively long closure line 20-22 reduces the risk that the valve element 5 will close abruptly, that is, will be pulled suddenly towards the valve seat 10, when the valve 25 is mounted in the wrong flow direction. Thus, the risk of Uwater hammer" is kept small.

As can be seen in Fig. 3, the valve seat 10 is of a concave construction; that is, the sections 21 are sloped radially inward, so that the sections 22 have a radial 30 spacing a to the sections 20. This spacing a is of the order of magnitude of 0.1 to 0.2 mm. The valve element 5 must be sufficiently deformable to be able to follow this

- 12 curvature. In Fig. 3, the degree of concave curvature has been exaggerated.

The concave construction of the valve seat 10 has the following effect: when the closing force on the valve 5 element 5 decreases, the deformability of the valve element 5 will initially cause a leakage in the radially inner area of the valve seat 10, so that fluid can escape via the sections 22 into the free spaces 23. As the pressure decreases further, a continuously enlarging 10 opening will form along the sections 21, so that here further fluid can flow through. When the valve element 5 finally lifts away from the valve seat 10 and also releases the sections 20 of the closure line, the valve is completely open. Subsequently, throttling is effected 15 only through the spacing between the valve element 5 and the closure line 20-22.

Claims

- 13 C L A I M S:

1. A radiator valve with a valve seat surrounding an opening that closable by a valve element that, in a closed 5 position, bears on the valve seat along a closure line, wherein the closure line has at least one section which is directed inwardly into the opening, and wherein on the outside along the closure line a free space is provided, even in the closed position of the valve element.

10 2. A valve according to claim 1, wherein a plurality of such sections are provided, the said sections being distributed uniformly about the circumference of the opening. 3. A valve according to claim 1 or 2, wherein the 15 region of the valve seat opposite to a plane defined by the radially outermost circumferential part of the opening is sloped away from the valve element.

4. A valve according to claim 3, wherein the said region has a maximum spacing from the plane of 20 approximately o.1 to 0.2 mm.

5. A valve according to any one of claims 1 to 4, wherein the valve seat is formed on a seat element, and the free space comprises a clearance space in the seat element. 25 6. A valve according to claim 5, wherein the clearance space is bounded by a sloped base.

7. A valve according to claim 6, wherein the outside of the base merges into the closure line.

8. A valve according to claim 6 or claim 7, wherein 30 the base has an angle of inclination in the range from 30 to 90 .

9. A valve according to any one of claims 1 to 8,

- 14 wherein the free space is formed in the valve element (5') and the valve element is non-rotatably located in relation to the valve seat.

lo. A valve according to any one of claims 1 to 9, 5 wherein the closure line is star-shaped.

11. A valve according to any one of claims 1 to 10, wherein the valve element (5) has an adjustable stroke limitation. 12. A radiator valve substantially as herein 10 described with reference to, and as illustrated by, the accompanying drawings.