GB2201493A - Interchangeable flow regulating device - Google Patents

Abstract

An interchangeable regulating device, making it possible to adapt the hydraulic characteristics, i.e. the coefficient of flow, of a thermostatic valve to the nominal heating-power of a radiator on which it is fitted, comprises a one-piece sleeve (10) closed at one of its ends by a gland (15), provided in the wall of which is at least one aperture (20) and whereof the other end is provided with a hole (29) whereof the diameter is chosen in order to provide a pre-determined coefficient of flow. A valve closure (12) is supported within the sleeve 10 on a stem (11) which is controlled through a rod (37) by a thermostat (not shown). An internal flange (27) on the sleeve (10) provides a back seat for the closure (12) when the gland (15) is removed. <IMAGE>

Description

INTERCHANGEABLE REGULATING DEVICE The present invention relates to an interchangeable regulating device making it possible to adapt the hydraulic characteristics, i.e. the coefficient of flow, of a thermostatic valve to the nominal heating-power of the heating radiator on which it is fitted.

The invention relates more particularly to thermostatic valves used for radiators fitted in central heating installations supplied with water superheated by an urban heating system.

In central heating installations of this type, the feed water is in most cases at a temperature of between 110 and 1300C, whereas the return water is at a telltperature 50 te 60 C lower than that of the feed water. It will be understood that with such a temperature difference, the desired heating-powers of the radiators ar obtained with a .sith u OF of flow of t water.

The result is that the thermostatic regulation of these radiators is difficult to achieve correctly and cannot be effected by a single type of thermostatic valve covering a wide range of rates of flow. One solution would consist of pro-ducing a series of valves, each of them suitable for a narrow range of rates of flow. But this would lead to excessively high production costs.

It is the object of the present invention to provide an interchangeable device fitting in a thermostatic valve body for adapting the latter to the rate of flow of heat-carrying fluid passing therethrough. Thus, with a single type of valve body, one could cover a wide range of rates of flow by virtue of this interchangeable device which provides a pre-determined coefficient of flow for the thermostatic valve on which it is fitted.

To this end, the invention relates to an interchangeable regulating device for a thermostatic valve, whereof the body is provided with an inlet tube, an outlet tube and a tube for the fitting of the regulating device, the said body comprising internally an annular. flange in the form of a seat, characterised in that it comprises a sleeve cast in one piece, of general cylindrical shape, closed by a gland, provided in the wall of which is at least one aperture, whereof one of the ends is screwed into the tube provided for this purpose and the other end is engaged in a tight manner in the annular flange of the body, the latter end being provided with a hole whereof the diameter is chosen in order to provide a pre-determined coefficient of flow.

The invention is described hereafter in detail with reference to the accompanying drawing showing one embodiment, given as a non-limitingexample and in which: The drawing is a sectional view of a thermostatic valve body equipped with an incerchangeable regulating device accordiny to the invention, illustrated in the closed position on the left of the drawing and in the open position on the right of th same drawing.

The valve body 1 illustrated, intended for a central heating installation, comprises a tapped inlet tube 2, on the axis X-X, through which the heat-carrying fluid arrives, a threaded outlet tube 3 leading to the radiator (not shown), on the axis Y-Y perpendicular to the axis X-X and a third tube 4, on the axis X-X, provided with a tap 5 and a thread 6, opposite the inlet tube 2. The inner cavity 7 defined between the three tubes 2, 3 and 4 of the valve body 1, comprises internally, on the side communicating with the inlet tube 2, an annular flange 8 of diameter D in the form of a seat.

The regulating device 9 which is the object of the invention, is composed of a sleeve 10, on the axis X-X, open at one of its ends, inside which are arranged a valve-holder 11 supporting at its end a closure valve 12, a return spring 13 concentric with the valve-holder 11, a cup 14 in which the valve-holder 11 may slide and on which one of the ends of the spring 13 rests. The sleeve 10 is closed by a gland 15.

The sleeve 10, of general cylindrical shape, on the axis X-X, comprises in succession from top to bottom in the drawing, on its outer surface: - a hexagonal surface 16; - a flange 17 whereof the lower face constitutes a joint bear ing-surface; - a threaded part 18; - a cylindrical part 19 of smaller diameter than that of the threaded part T8 in which two opposed apertures 20 of rect angular section are provided. The diameter of the cylindrical part 19 is greater than that D of the flange 8 of the body ; - a cylindrical part 21, of slight thickness, whereof the dia meter is slightly less than that D of the flange 8 of the body 1, connected to the cylindrical part 19 by a groove in which an O-ring 23 is housed.

Inside the sleeve 10 there are machined in succession, from top to bottom in the drawing: - a cylindrical bore 24 on the axis X-X; - a tap 25; - a bore 26, on the axis X-X, of smaller diameter than that of the bore 24, whereof the connection to the tap 25 forms a radial shoulder 42. This bore 26 is extended as far as the bottom of the sleeve 10; - a flange 27, provided with a frustoconical bore 28, converging in a downwards direction, projecting into the bore 26 approxi mately half way along the height of the latter.

The end of the sleeve 10 opposite the bore 24 is provided with a hole 29 which extends towards the inside of the sleeve by a flared, conical cup 30, forming a seat for the valve 12.

The -diameter of the hole 29 is adapted to provide a predetermined coefficient of flow.

The valve-holder 11, of general cylindrical shape on the axis X-X comprises at one of its ends a head whereof the connection to the body of the valve-holder forms a shoulder 31 and at its other end a shoulder 32 and one or more attachment grooves 33 (one is illustrated in the embodiment). It terminates in a projecting conical part 34. The valve-holder 11 is provided over approximately two thirds of its length with a blind hole 35 which opens in a cup 36 provided in its head.

The valve 12, made from a heat-resistant elastomeric material, is in the shape.of a frustum of a cone of slight conicity, on the axis X-X, whereof the smallest of the bases is attached te a cone having a large angle at the apex. This angle is slightly less than the angle.at the apex of the conical cup 30, forming a seat, of the sleeve 10. The valve 12 is provided with a blind hole, opening into the base of the talv, the shape of which matches that of the groove 33 and of the conical end 34 of the valve-holder. The diameter of the base of the valve 12 is slightly greater than the smallest diameter of the frustoconical bore 28 of the flange 27 of the sleeve 10.

The gland 15, of known type, comprises a control rod 37, provided with a stop washer-38, an O-ring 39 ensuring the tightness of the passage of the rod 37 and a cup 40 keeping the O-ring 39 in place.

The assembly of the device 9 according to the invention takes place in the following way. In the first place, one proceeds with the assembly of the sub-arrangement of the valve 12 and valve-holder 11. For this, the spring 13 is placed around the valve-holder 11, resting on the shoulder 31. It is then compressed by means of the cup 14, then a washer 41 is placed in abutment against the shoulder 32, finally the valve 12 is force-fitted on the projecting end 34 of the valve-holder 11, the groove 33 of the latter and its matching shape provided in the blind hole of the valve 12 providing a strong attachment.

It is thus the valve 12 which ensures locking of this subassembly.

The sub-assembly of the valve 12 and valve-holder 11 is then introduced into the sleeve 10. The valve 12, whereof the diameter of the base is greater than the diameter of the frusto- conical bore 28 of the flange 27 passes with force through the latter owing to the elasticity of the elastomeric material which constitutes it. The sub-assembly of the valve 12 and valve-holder 11 is thus trapped by the sleeve 10, the periphery of the base of the valve 12 abutting against the lower side of the flange 27, preventing the sub-assembly from escaping.

The assembly of the device 9 is terminated by fitting the gland 15, which is screwed onto the sleeve 10 by the tap 25, the control rod 37 being engaged in the blind hole 35 of the valve-holder 11 and bearing against the end of this hole. The seal between the gland 15 and the sleeve 10 is ensured by the pressing of th gland against tne shoulds 42. The arrangement of the valve 12 and valve-holder 11 is kept in the open position by the spring 13 which is supported by its ends, on the one hand, on the shoulder 31 of the valve-holder 11, on the other hand, on the cup 14, itself supported on the upper face of the flange 27 of the sleeve 10.

The device 9. is then put in position in the valve body 1 by screwing the sleeve 10 into the tube 4 by virtue of the tap 5 and the screw-thread 18 which co-operate. The tightness between the sleeve-body is ensured by the lower face of the flange 17 which bears against a corresponding shoulder of the tube 4. When the sleeve 10 is screwed-in completely, its end provided with the hole 29 is engaged in the annular flange 8 of the body 1, the tightness between the latter and the sleeve 10 being ensured by the O-ring 23.

-The assembly of the valve is terminated by fitting the thermostatic head (not shown) to the tube 4 by screwing onto the screw-thread 6, the heat-sensitive element of said head bearing directly or through the intermediary of a push-rod on the free end of the control rod 37 of the valve 12.

The advantages provided by the device to which the invention relates are as follows: - this device makes it possible to adapt the coefficient of flow of a thermostatic valve, whilst having a single type of valve body. In fact, the hole 29, provided at the end of the sleeve 10 has a greater or smaller diameter depending on the flow of heat-carrying fluid which one wishes to allow to pass into the radiator. For a small flow, there will be mounted in the valve body 1 a device 9 whereof the diameter of the hole 29 is small, whereas for a considerable flow, the hole 29 will have a larger diameter. The greater or lesser pressure drop created by the hole 29 makes it possible to limit the flow of heat-carrying fluid for a given pressure.

- This device makes it possible to correct easily a calculation error which r s still pcsile ir. t desigr. c; a central heating installation. For this, it is sufficient to replace the regulating device fitted originally by another, better suited device, without it being necessary to remove the thermostatic valve.

- This device makes it possible to adapt a central heating installation to a dropor an increase in the temperature of the heat-carrying fluid distributed by the urban heating system solely by changing the regulating device 9, the valve body originally fitted being retained.

- The replacement of the gland 15 as a result for example of wear of the O-ring 39 is possible without it being necessary to isolate the radiator. In fact, when the gland 15 is separated from the sleeve 10, the seal is obtained by the fact that the valve 12 bears by the periphery of its base against the lower face of the flange 27 of the sleeve 10, which prevents the heat-carrying fluid from escaping outside the valve.

- Retaining the constituent parts of the sub-assembly of valve 12 and valve-holder 11 is ensured by the valve 12 itself anchored to the end of the valve-holder 11 by the groove 33 and the matching relief provided in the blind hole of the valve 12, which allows mechanised mounting of this sub-assembly.

- The sleeve 10, cast in one piece, constitutes an extremely strong casing protecting the mechanism which it contains in a satisfactory manner.

Claims (6)

1. Interchangeable regulating device for a thermostatic valve whereof the body is provided with an inlet tube, an outlet tube and a tube for the fitting of the regulating device, the said body comprising internally an annular flange in the form of a seat, wherein it comprises a sleeve cast in one piece, of general cylindrical shape, on the axis X-X, closed by a gland, provided in the wall of which is at least one aperture, whereof one of the ends is screwed into the tube provided for this purpose the other e..d is engaged sn a tiglst talln t in the annular flange of the body, the latter end being provided with a hole, on the axis X-X, whereof the diameter is chosen to provide a pre-determined coefficient of flow.

2. Device according to Claim 1, wherein disposed inside the sleeve are a valve-holder, on the axis X-X, provided at one of its ends with a closure valve, a return spring concentric with respect to the valve-holder. and a cup, on the axis X-X, in which the valve holder may slide, the latter being supported on a flange provided inside the sleeve.

3. Device according to Claim 1 or 2 wherein the valve-holder comprises at one of its ends, a head whereof the connection to the body of the valve-holder forms a shoulder and at its other end, which is terminated by a projecting conical part, at least one attachment groove.

4. Device according to any one of claims 1 to 3, wherein the valve-holder, the return spring, the cup, and the valve form an arrangement whereof the assembly is ensured by the valve force-fitted on the end of the valve-holder comprising the projecting conical part, the attachment of the valve on the valve-holder being provided by the groove engaging with a matching relief of a blind hole provided in the valve.

5. Device according to any of the claims 1 to 4, wherein the diameter of the base of the valve - is greater than the smallest diameter of the frustpconical bore of the flange of the sleeve, which ensures the rear tightness of the valve when -the gland is removed.

6. Interchangeable regulating device for a thermostatic valve substantially as hereinbefore described with reference to the accompanyir.g drawings.