Regulating valves of various constructions and for different purposes are already known for insertion in valve housings in a liquid-carrying medium.

For example, such a valve, a so-called flow valve, is known from DK patent no. 171285 B1, which is intended for insertion in a valve housing in a plant for central heating. This valve, for controlling the flow of liquid in a central heating plant or the like, consists of two concentric elements, circular plates or cylindrical skirts. These elements have a number of holes, and are arranged to be turned in relation to each other to bring about a restriction point with a fixed opening position which is selectable among several opening positions with different areas lying in an equidistant manner along the circumference of the elements, in that the number of holes in the one element is equal to the number of blocked-off areas in the second element.

In, for example, central heating plants, one of the places where use is made of valves of such a type, thermostatic valves for example are provided in different rooms for regulation of the heating, and for that matter this can also involve cooling in connection with air-conditioning. When one or more of these thermostatic valves in one or more of the rooms opens or closes for the through-flow of the heat-carrying medium, the pressure conditions in the whole of the plant are changed, and for this reason it is desirable to have a self-regulating valve inserted in the circuit for regulating the flow.

Plants of these said types are often divided into several part-strings with one or more radiators or heat receivers for each part string, which makes it desirable to have a self-regulating flow valve in each part string.

In order for this self-regulating flow valve to be able to regulate the flow quickly and precisely, it is necessary to have a regulation component with low inertia.

A thin membrane is one of the possibilities for reducing this regulation inertia, which has not hitherto been possible, in that with increasing differential pressure the membrane in the known valves has a tendency to be pressed out through the relatively large openings which are formed in the housing, the opening area of which the membrane is intended to regulate.

According to the invention, this is achieved by the cross-section/clearance of each opening preferably being less than a half part of the extent, which is covered by the rolling of the membrane along the cylindrical wall. The wall and openings will hereby consist of a pattern of more-or-less closely-sitting holes, where the material between the holes constitutes a form of net or mesh structure.

In this manner an adequate support for the roller membrane is provided in the radial direction, in that it is advantageous that the membrane is made of a relatively thin material. By making use of a thin membrane in connection with the type of openings which are normally employed in connection with roller membranes in valves and the like, it can be experienced that the membrane will be pressed out through these slot-formed openings due to the overpressure prevailing in the valve, whereby the reaction speed and lifetime of the membrane are considerably reduced.

By making use of a relatively thin membrane, the possibility is also achieved for a precise regulation at low differential pressure, since the influence of the rolling resistance is less with smaller membrane thickness.

Moreover, the use of a thin membrane provides the advantage that the membrane area and herewith the membrane diameter can be reduced, since the rolling resistance is less with smaller membrane thickness, whereby a compact construction is achieved.

It is precisely the use of a relatively thin membrane for the roller membrane that provides a smooth, quickly reacting and more precise regulation of the flow in the valve, also at high differential pressure, in that the rolling resistance of the membrane becomes less with smaller membrane thickness.

The configuration of that part of the valve which comprises openings which are intended to be able to be regulated with regard to the flow in the area from open and to closed condition, can be effected in several ways. The area where the roller membrane shall have its regulation function can, for example, be configured by providing a number of rows of holes in a belt around the circumference of the valve's cylindrical housing.

These rows of holes can possibly be displaced from each other in such a manner that the centre of the hole lying immediately above is displaced so much to the side that it corresponds substantially to a half of the distance between the centres of two holes lying at the side of one another. Hereby a greater number of holes in relation to the axial extent of the belt is achieved. It is also possible to place holes of different diameters in the belt, in that a very close positioning of holes in the belt is achieved hereby.

The area with the holes can also be produced by placing a net on the inner side of the cylinder part, in which cylinder part some large holes or cut-outs

are formed, where the net can be placed so that the holes or the cut-outs are covered by the net.

The net can be made of metal or plastic of a type with a strength, which is great enough to withstand the pressure in the valve.

Together with the size of the holes, the positioning of and the distance between the holes contribute towards determining how great a flow can be effected through the valve when the membrane opens the valve for full flow.

In one of the ends, preferably that end which faces towards the direction of flow, a pre-setting element for setting the desired nominal flow through the valve is provided, on the basis of which flow a regulation is effected by means of the roller membrane. To make the valve as short as possible in the axial direction, it is advantageous for this pre-setting element to be configured in a disk-shaped manner.

The membrane controlled by the differential pressure in the valve regulates the differential pressure of the liquid-carrying medium across the adjustable pre-setting element. In this way, a constant differential pressure is maintained across the pre-setting element.

It is hereby achieved that the valve according to the invention can be set to allow only a predetermined fixed maximum amount of the heat-carrying medium to flow through the valve, independently of the heat exchangers, radiators or the like which can otherwise exist in such a plant, and independently of the pressure conditions in the plant. If the differential pressure is increased, for example due to the closing of one or more or all of the remaining valves in a pipe branch, it will not result in an increase in the flow in the individual heat exchangers.

The drawing In the following, preferred embodiments of the invention will be described with reference to the drawing, where fig. 1 shows a flow valve according to the invention, fig. 2 shows a flow valve as shown in fig. 1, seen in the section A-A, fig. 3 shows a ball valve intended for insertion of a flow valve according to the invention, and fig. 4 shows a section through a ball valve with flow valve inserted.

In the following, a preferred embodiment of a regulating valve 1 for insertion in a form of valve housing in a plant with liquid-carrying medium is described, where the regulating valve or the flow valve 1 comprises a housing 2 which, via a regulating net 3, is connected with a top 4. Between the top 4 and the regulating net 3, an outer circumference of a membrane 5 is disposed in a sealing manner, said membrane 5 for regulation of a number of holes 6 formed in the regulating net 3 also having an inner circumference which is secured in a sealing manner to a membrane guide 7. The membrane guide 7 is displaceable axially in relation to the housing 2, and between the guide 7 and housing 2 there is a spring 8 which works to bring the membrane 5 and guide 7 to a position which makes it possible for the liquid-carrying medium to flow through the holes 6 formed in the regulating net 3. In a channel 9, which extends from an inner chamber 10 in the top 4 of the flow valve 1 through the membrane guide 7 to an area near a pre-setting element 11, which pre-setting 11 is provided with a number of holes and a rotatable disk with a corresponding number of openings, which can be covered to a degree depending on how great a flow the pre-setting

11 shall allow to pass. If just one of the holes in the pre-setting element 11 is not covered, there will be a difference in pressure between the medium at the pre-setting element 11, which is the inlet side of the flow valve, and the internal chamber 10 in the top 4 of the flow valve 1. The membrane 5 can be briefly described as a short tube, the one end of which slopes in at a radial distance over the other end, after which the radially outermost part is secured tightly between the top 4 of the valve and the regulating net 3 or the housing 2, all depending on whether the housing 2 and the net 3 are produced as one unit or produced as separate units. The radially innermost part of the membrane 5 is secured tightly to a membrane guide 7. With the displacement forwards and backwards of the membrane guide 7 in the direction of the longitudinal axis of the valve 1, the membrane 5 will be tilted to a greater or a smaller degree around itself, whereby the radially outermost part can become longer and/or shorter and hereby execute a form of rolling across the holes 6 which are distributed like a belt along the circumference of the regulating net 3.

In the embodiment described above, the regulating net 3 is formed by openings, which are provided in the cylindrical surface of the valve itself.

In a further embodiment, in the area in the valve 1 where the membrane 5 executes its rolling regulation, some large openings or cut-outs 12 can be formed. These cut-outs 12 in the housing 2 extend substantially along the whole circumference of the housing 2, broken only by a form of stiffening elements 13, said stiffeners holding the upper and lower parts of the housing 2 connected with each other. A net is placed inside the housing 2 and opposite the cut-outs 12, for example in the form of a perforated cylindrical plate or a similar surface with a form of mesh structure, so that the holes or the cut-outs are covered by the net. A countersinking can possibly be formed to create an even transition for the roller membrane 5 from the housing to the net.

From fig. 2 it will be understood that a medium from the area immediately in front of the pre-setting element 11 will flow through a channel 9, which is formed in the membrane guide 7, and exercise a force against the upper side of the membrane in the chamber 10, so that the membrane guide 7 compresses the spring 8.

The medium will also flow through the pre-setting 11 and further through the holes 6 in the regulating net 3, which are not covered by the roller membrane 5.

By a suitable dimensioning of the area of the membrane 5 in relation to the force of the spring 8, a desired difference in pressure across the pre-setting 11 can be produced by a rolling of the membrane 5 in over the holes 6.

The holes 6 can be configured in many ways, in that it is not the actual shape of the hole, which is important for the support of the membrane 5.

The support of the membrane is effected by the relationship between the area of the holes 6 and the area of the material, which surrounds the holes 6 in the belt consisting of the holes.

The adjustable pre-setting 11 can be set for a given through-flow opening by turning around the longitudinal axis of the valve 1, and can possibly be locked firmly in its setting. It can, for example, be configured as follows.

In the one end of the valve 1, preferably in the inlet opening, one or more openings are provided in the housing 2. A disk-shaped plate, similarly with one or more openings, is placed concentrically around the longitudinal axis of the valve 1, so that the plate can be turned around its centre. The plate is held firmly in the axial direction in the housing 2 by a locking ring 14. The possibility is hereby provided for the regulation of the through-flow of liquid- carrying medium. The regulating can be effected by providing one or

several rows of holes of different sizes along an arc on the disk, which holes can be positioned either individually or several at a time opposite a larger opening in the housing 2. The regulating can also be effected by providing the holes of different sizes along an arc in the housing 2, and a larger opening in the rotatable disk can be placed so that it is possible to turn the disk into such a position that the larger hole in the disk can be positioned opposite one or more of the holes provided in the housing 2, thus hereby defining a possible maximum flow through the flow valve 1.

To ensure tightness between the flow valve 1 and the receiving valve housing in which the flow valve 1 is accommodated, a recess 15 is formed in the housing 2, said recess being intended to partially receive a not- shown gasket or seal.

Due to the short and compact configuration of the flow valve, it will be possible, for example, for a ball 20 in a ball-cock 16 to be used as valve housing, in that the flow valve can be placed in the through-flow opening of the ball 20. In figs. 3 and 4, a flow valve 1 is seen placed in a ball-cock 16 which comprises an inlet 17 and an outlet 18 which can be provided in the normal manner with connection means and/or threads, and a lever 19 which can be turned and which stands in fixed connection with a rotatable ball 20 which is housed in the ball-cock 16 in a tightening manner. On the side of the ball-cock 16, preferably placed opposite the inlet opening in the ball 20 when the ball 20 is turned by means of the lever 19 into a position in which the cock 16 is closed, a further opening 21 is provided, which, during use, is closed by means of a form of removable plug 22. This plug 22 can be secured in the ball cock 16 in the normal manner, for example by means of a thread or in a correspondingly removable manner. A not-shown sealing gasket is provided between the plug 22 and the ball cock 16.

When the lever 19 is turned until the ball 20 stands in its closed position, which in this embodiment will be when the lever 19 points in the direction of the additional opening 21, the plug 22 can be removed without the escape of the liquid-carrying medium. In this position, a flow valve 1 can be placed in the ball 20, and thus in this way a regulation of the liquid-carrying medium can be achieved. Hereby the advantage is achieved that the flow valve 1 can be replaced relatively easily, used to change the amount of flow or, if it should be necessary, be serviced, and without the necessity of having to drain the liquid-carrying medium from that part of the plant in which the flow valve 1 is placed.

With this compact solution, it is also achieved that it is not necessary to have additional valve housings mounted in such a plant. In different forms of heating or cooling plants, for example for the controlling of the temperature in housing accommodation and the like, there are often in such a plant several part strings for the control of the temperature in the individual rooms in the house, and in many cases a ball-cock will have been provided in each part-string, so that it is possible to shut off the flow through the individual part-strings.

The flow valve is not limited to use in ball cocks, but is ideal for building-in in all places, especially where the space at disposal is limited.