The invention still more particularly relates to fluid control valves for use in refrigerant loops, subject to high internal pressures, high differential, internal pressures in either direction and a wide range of temperatures and adapted for the fitting of a layer of insulation material.

Fluid control valves are presently offered in numerous variants to satisfy various user requirements. User requirements may e. g. pertain to rated pressure, certification according to particular codes, such as safety codes, materials used in order to ensure compatibility with the fluid medium, method of control, e. g. hand wheel operated, solenoid operated, pilot operated etc, method of conduit connection, e. g. screw type fittings, welding fittings of different kinds, etc.

Some of these requirements affect only particular valve parts; e. g. particular requirements to the spigots for compatability with particular kinds of piping could generally be met by offering different types of valve housing, whereas other parts of the valve, e. g. valve cone, valve spindle, bonnet, etc. might be identical.

Thus it will generally be the most economic procedure to assemble the valve from a number of parts, among which several are interchangeable with other parts.

However, this complicates proper identification of the valve as different valves may be distinguished solely by

internal components, which are not visible from the outside. Full information will generally be supplied, e. g. by a leaflet or a tag included with the shipment of the valve. However, this does not solve the problem of obtaining complete identification of a valve already installed, e. g. for the purpose of later reordering.

One method of labelling a fluid control valve, which has been offered on the market, comprises manufacturing a type plate and securing the type plate to the valve housing by means of rivets driven into blind holes made in the valve housing. This solution may not be satisfactory. The drilling of blind holes into the valve housing is basically an undesirable procedure in view of the hazards of impairing the capability of the housing to withstand internal pressures. Similar considerations apply to the hammering of rivets into the blind holes.

The type plate may come loose, e. g. give rise to rattling caused by vibrations which often prevail on this type of structures. Unauthorized replacement of the type plate may leave no visible traces. Furthermore a type plate attached onto the surface of the valve housing will in many cases be buried within a layer of insulation material, applied in order to save energy in case of the valve carrying hot or cold fluids.

The invention, in a first aspect, provides a method as recited in claim 1.

By this method, the label is manufactured separately from the valve, thus permitting effective methods of engraving insignia as required, e. g. a computer controlled engraving or etching operation. The forging of the label by an operation where the valve housing as well as the label itself sustain partial plastic deformation ensures that any replacement of the label is bound to leave

visible traces. The forging ensures a firm retention of the label so as to endure loads, such as vibrations.

The term partially plastic material in the present context refers to a material which is adapted for being deformed with residual changes of shape, possibly also with a partial elastic deformation. Suitable materials include metals adapted for forging, such as stainless steel, mild steel, brass, and many others.

According to a preferred embodiment, the label base comprises a projection having an annular rib, whereas the label comprises an opening by which it is adapted for being driven to engage the projection with associated partial plastic deformation of at least parts of the rib, and at least parts of the label. This provides a simple method of manufacturing the label and a simple method of fitting the label onto the valve.

According to preferred embodiments, the method may comprise providing zones adapted for creating, during the stage of driving the label onto the projection, localized plastic deformations. This ensures that permanent traces of the fitting will be visible on the label as well as on the label base while avoiding the necessity of a general deformation of the label and/or of the label base which might otherwise require excessive force.

According to a preferred embodiment, the label base is provided on an extension of the valve housing, such as a bonnet of the valve. This retracts the location of the label from the fluid conduit and thus leaves more room for the installation of insulation material, while still permitting leaving the label visible. It also facilitates access to the label, e. g. for the purpose of thawing

loose a cover layer of ice with the purpose of reading the label.

According to a preferred embodiment, the label base is provided peripherally to the bonnet and adjacent to a spindle opening of the valve. This presents the label in the position best suited for inspection by the operator who will generally be expected to access the valve from the side of the spindle opening where the spindle with the hand wheel will usually be accessible. The peripheral positioning reduces heat conduction from the valve housing and thus facilitates e. g. removal of ice to facilitate reading the label insignia.

This positioning also facilitates other operations, such as painting of valve. For the purpose of painting the valve housing, it is a standard practice to cover the opening for the valve spindle by a protective hood in order to prevent paint from entering the opening in the valve housing. By arranging the label base adjacent the valve spindle opening, the protective hood is easily adapted to cover also the label so as to prevent the application of paint onto the label.

The invention, in a second aspect, provides a labelled fluid control valve as recited in claim 7.

In this context the term partially plastic material refers to a material capable of being deformed with a residual change of shape, e. g. by forging. Suitable materials include many metals, among which stainless steel, mild steel, brass, and many others.

This labelled fluid control valve offers the option of including suitable label information permanently attached to the valve in such way that any unauthorized

replacement of the label is bound to leave visible traces.

Preferred embodiments of this control valve appear from dependent claims.

Further features and avantages of the invention will appear from the appended description of preferred embodiments given with reference to the drawings wherein Fig. 1 shows a valve according to the invention installed as part of a fluid conduit, illustrated in axial section, Fig. 2 illustrates part of Fig. 1 in an enlarged scale, and Fig. 3 shows a plan view of label ring according to the invention.

All figures are schematic and not necessarily to scale and illustrate only those parts which are essential in order to enable those skilled in the art to understand and practise the invention whereas other parts are omitted from the drawings for the sake of clarity.

Throughout the drawings identical references have been used to designate identical or similar features.

Reference is first made to Fig. 1 for a description of the valve according to the invention.

The valve 1 basically comprises a valve housing 3 assembled from a valve body 21 and a valve bonnet or cover 22. The valve housing receives a closure element 4 which is axially displaceable within the valve housing in order to permit a valve cone to sealingly engage a valve

seat 6 or selectively to lift off the valve seat. In this way a fluid conduit 2 defined by the valve housing 3 may be selectively opened or blocked to fluid passage, in a way which is generally known in the art.

The closure element 4 basically comprises a valve cone adapted for permitting sealing engagement with the valve seat 6 and supported by a valve stem 10.

A spindle 5 basically comprises a spindle shaft 25 fitted with a spindle hand wheel 28 by which the shaft may be rotated. The shaft 25 is received in the valve bonnet bore 23, centered around an axis 11, and provided with seals or the like for sliding engagement with the shaft as known in the art.

The valve 1 is connected with pipes 41 which are butt welded to respective studs of the valve housing 3 in a way which is well known in the art. The pipes 41 and part of the valve 1 are provided with a cover layer of insulation 40 wich serves the purpose of heat insulating the fluid conducting parts.

The insulation cover 40 basically encloses all of the valve body 21, whereas part of the bonnet 22 extends through the insulation cover to be visible from the outside.

The bonnet by the bonnet bore 23 receives the spindle shaft 25 in rotatable fashion. The spindle shaft 25 may by its top end be fitted with a hand wheel 28 as partially illustrated in the upper part of Fig. 1 to the left of the axis 11. Depending on operational requirements it may in some cases be preferred to remove the hand wheel 28 and to install a protective cap 29 as partially illustrated in upper part of Fig. 1 to the

right of the axis 11. For instance the hand wheel 28 may be installed during a start-up phase, whereas it may be removed during a state of regular operation of the process. When installed the cap 29 may tightly seal the spindle opening in the top of the valve, and it avoids unwanted accidental manipulation of the valve.

Reference is now made to Fig. 2 which illustrates the top part of the valve of Fig. 1 but to an enlarged scale.

Thus Fig. 2 illustrates an external bonnet thread 33 near the top end of the bonnet and adapted for securing the cap 29. The bonnet further comprises, at a position just below the bonnet thread 33, a label seat 34, which seats a label ring 36.

The label seat 34 essentially comprises an annular rib 35 and, below the annular rib 35, a shallow peripheral recess delimited downwardly by an annular ledge 37.

The label ring 36 provides a radially extending peripheral rim or ledge visible from above, from the position where the hand wheel or the cap is installed.

Reference is now made to Fig. 3 for a description of the label ring 36. The label ring comprises a ring-like body cut or stamped from a sheet, such as a 1 mm sheet of stainless steel. The label ring on one side comprises insignia 42 which provides the label information. The insignia are drawn by a manual operation or by a computer controlled operation, e. g. involving engraving, stamping, etching or printing or similar.

The ring inner edge comprises circular edge portions 39 separated by three secant edge portions 38. The secant edge portions 38 are spaced by equal subtending angles

and obscure part of the otherwise circular lumen defined by the ring.

The label ring is matched to the label seat 34 in such way that the ring may be forced axially over the end of the bonnet, clearing the bonnet thread and being expanded by engagement with an inclined front surface of the annular rib 35. While being forced over the annular rib 35, the label ring 36 or at least parts hereof deform partially resiliently and partially plastically to leave afterwards partial zones of plastic deformation of the rib 35. Once driven home against the ledge 37, the ring is firmly engaged by residual resilient forces and by the forging caused.

In a preferred embodiment, the outer diameter of the rib is 40.5 mm, whereas the diameter of the recess below the rib is 40.2 mm. Thus the diameter of the rib exceeds that of the recess by 0.75%. A sealing ring according to an embodiment adapted for mating engagement with this label seat has a radius in the circular edge portions of 20.55 mm, whereas the distance from the centre to the closest portions of the secant edge portions is 19.95 mm. Thus the distance from the centre to the closest part of the secant edge is 97% of the radius of the circular edge portions.

This ring adapts to label seat under partial plastic deformation of the secant edge portions and of contacting portions of the annular rib 35 and so as to provide a firm engagement with the label seat.

Although various components have been explained in particular detail above, it should be remembered that this explanation has the sole purpose of exemplifying how the invention might be practised, but is in no way intended to limit the scope of the invention which is defined exclusively by the appended patent claims.