DE29918811U1 - Housing for installing measuring and control devices, especially those with inline suitability - Google Patents

Description

10/25/1999 .%&Lgr;. ^: ' ,:.\. ^s * I? '"

Housings for the installation of measuring and control devices, especially those with inline suitability

The innovation relates to a housing for the installation of measuring and control devices, in particular those with inline suitability, according to the preamble of claim 1.

Housings of the generic type are used when the arrangement of such measuring or control devices in pipelines at their installation location should not lead to any significant housing-related disruptions to the pipe flow. Housings that have these properties are also referred to as inline-capable. Disturbances usually occur when the measuring and control devices have independent housings that represent a discontinuous change in cross-section with respect to their internal passage compared to the connected pipeline. Housings that are inline-suitable for the installation of measuring and control devices are therefore required to have a seamless internal passage that connects to the pipe cross-section and that no sump or dome is formed in the housing in the area of the connection pieces for the measuring and control device. Regardless of the course of the pipeline (for example horizontal or vertical), the housing of the generic type must empty itself automatically and completely. A largely trouble-free flow through the housing for accommodating measuring and control devices is, on the one hand, a prerequisite for error-free measurement and control, and the avoidance of dead spaces in the form of a sump or dome, on the other hand, ensures residue-free emptying of the pipeline without product carryover and reliable so-called CIP cleaning (CIP: cleaning in place).

There has therefore been no lack of efforts to create an inline-capable housing with standardised connection nozzles that is independent of the manufacturer of the respective measuring and control equipment, but which is not suitable for use in the field of sump- and dome-free design and the variety of possible housing configurations.

083GWI1A0 * ::.. ·: :": :'V/*:

10/25/1999 .:λ\· ^: ' .:. ^: .. ^: * l'J '"·

were only partially successful. The two known, possible, practical manufacturing processes for such housings are briefly described below.

In the first method, a collar is made on a cylindrical housing shell at the location of the connecting piece to be attached, to which the connecting piece is welded. As a rule, two connecting pieces are provided on the housing shell in this way, which are then machined in alignment in one clamping. In order to be able to weld on the connecting piece, the collar must extend a little beyond the outer diameter of the housing shell. In order to achieve a sump-free or dome-free embedding of the cover closing the connecting piece, the latter should also be positioned so that the inner surface line of the cylindrical housing shell, which runs in the meridian plane of the connecting piece, is continuously continued on the inner, flat boundary surface of the cover. The precise, gap-free and sealed embedding of the cover in the necked-out housing shell requires extensive machining of the housing in this relevant cover plane, which is fundamentally not possible due to the fact that there is not enough material available in this plane over a circumference of 360 degrees. For this reason, a sump-free or dome-free embedding of the cover in the necked-out connection piece is not possible, so that a housing designed in this way can only be certified as suitable for inline use if the connection pieces are arranged horizontally.

The second method starts with two hemispherical shells, each of which already has a connecting piece at the end opposite the great circle diameter. These blanks are usually centrifugally cast or drop forged parts. The two spherical half-shells are welded together at their great circle diameter and are placed on the inner surface of the connecting pieces in the meridian plane, perpendicular to their common axis of symmetry.

083GM1A0 " .:···. . '· : :

A pipe socket is then welded onto each side and both the pipe sockets and the connecting sockets are machined in one set-up. From this outline of the manufacturing process, it is clear that such a housing can have a maximum of two connecting sockets. The arrangement of further connecting sockets would pose the same problems as the first manufacturing process.

However, the spherical shape of the housing, which is advantageous in terms of pipe connection, leads to a disadvantage in the present case, which is that with a horizontally arranged pipe and horizontally oriented connection pieces, there is a considerable sump space in the spherical cap in the lower area of the housing, which rules out an arrangement of the housing in this position, so that this solution is only partially suitable for inline use.

When manufacturing using the second method, it has also been shown that the housing shell warps considerably, particularly when making the housing openings for the pipe connection, as the housing shell, which is welded together from hemispherical shells, is subject to relatively high internal stresses which are released by machining. The subsequent welding of the pipe sockets results in additional stresses which cause further deformation of the housing shell. The welded pipe sockets must then be reworked by machining, particularly on the inside, as on the one hand the unmachined weld seam would not meet the inline requirements, and on the other hand distortion caused by welding is the norm and must be compensated for by machining rework as part of a machining allowance. The manufacture of such housings today is partly carried out with a rejection rate of 40% or more, and the housing configuration limited to a maximum of two connection nozzles does not meet all the relevant practical requirements for the required housing variety, so that other solutions for a housing of this generic type have long been sought.

083GM 1AO

25.10.1999

The innovation is based on the task of creating a housing of the generic type that can be manufactured in a variety of configurations in terms of size, number and arrangement of the connecting pieces and with a low reject rate and that is absolutely sump and dome-free in every installation position

This object is achieved by the features of claim 1. Advantageous embodiments of the proposed housing are the subject of the subclaims.

The desired housing variety with more than two connection pieces and, above all, the low rejection rate are ensured by the fact that the housing shell and the connection pieces arranged on it are produced from a base body, solely by machining. Modelling the connecting pieces from solid material is no problem with the modern machining machines available today. NC-controlled lathes with so-called swivel chucks in particular can easily machine two connecting pieces arranged diametrically opposite one another in one clamping. The most favourable initial geometry for the base body has proven to be a symmetrical spherical layer, which is penetrated by a cylindrical bore corresponding to the inner diameter of the pipe, which runs perpendicularly and coaxially to the small circle diameter of the spherical layer. In addition to the favourable manufacturing geometry, this also results in a very harmonious external appearance of the proposed housing. The spherical zone delimiting the spherical layer must be dimensioned in terms of its radial dimensions so that the spherical zone at least envelops the fully formed connecting pieces, i.e. that the base body provides enough material that the connecting pieces can be modelled in their entirety from this material. The ball layer is also axially dimensioned so that the first and second pipe connections can also be machined out of the base body. The housing produced in this way remains largely

083GM1A0

25.10.1999

tension-free, so that distortion is avoided and the scrap rate is reduced to zero.

In addition, the proposed spatial form of the housing, which is made from solid material, now allows the ideal geometry of an inline-capable housing to be realized, so that the housing remains sump- and dome-free in any installation position and can therefore completely empty itself.

An advantageous embodiment of the proposed housing provides a cylinder on both sides of the base body and in the direction of the pipe axis, from which a relatively long pipe socket is machined. The diameter of the cylinder has the dimensions of the small circle diameter of the spherical layer, and the length of the cylinder is determined by the desired length of the pipe socket. This so-called extended base body can be manufactured relatively easily in one piece by turning. The relatively large length of the two pipe sockets protects the proposed housing against heat input when welding the pipes and is therefore particularly effective against distortion.

Modelling the housing with its fully developed connecting pieces from the proposed base body creates the possibility of a diverse housing configuration. Especially with large nominal pipe diameters, four or more connecting pieces can be provided on the housing, which according to a proposed embodiment are evenly distributed over the housing shell, whereby the maximum possible number of these connecting pieces is determined by the larger required minimum distance between adjacent connecting pieces, which results from the space required either for machining the respective connecting piece out of the base body or for two adjacent connecting elements. These can be adjacent joint clamps of the respective clamp connections or union nuts of the respective pipe screw connections.

083GM1AO

25.10.1999

The simplest way to manufacture the housing according to the innovation is, as another embodiment provides, to machine the base body out of solid material, preferably from cylindrical rod material. This requires an appropriately sized piece of round material that has the outside diameter of the ball layer. The ball zone is then turned and the central bore is made so that the base body thus created or the expanded base body is now available for further processing. This type of procedure is particularly recommended for one-off production and small-scale production.

10

For larger quantities, it is advantageous, as another embodiment provides, if the base body, taking into account a machining allowance, is made from a centrifugally cast part with the spherical zone formed on the outside, possibly a cylinder adjoining on both sides and a central, essentially cylindrical through-hole oriented along the pipe axis. In this case, to produce the base body as a starting body for further machining of the connecting pieces, only a slight machining in the area of the spherical zone, possibly machining of the cylinder adjoining on both sides and the central bore oriented along the pipe axis is necessary.

According to a preferred embodiment of the proposed housing, a clamping piece of a clamping connection, as defined for example in DIN 32676, is formed on each connection piece. 25

According to another embodiment, it is provided to form a threaded socket of a pipe fitting, as defined for example in DIN 11864, on each connection socket.

Examples of the innovation are shown in the drawing and are described below. They show

083GM 1AO

25.10.1999

Figure 1 shows a perspective view of a first embodiment of the housing according to the innovation with four connection nozzles and a long pipe nozzle on each side;

Figure 2 also shows in perspective a second embodiment of the housing according to the innovation with two connection pieces and a short pipe connection on each side;

Figure 3 also shows in perspective a third embodiment of the housing according to the innovation with six connection pieces and a short pipe connection on each side and Figure 4 shows the base body for a housing with six connection pieces, the base body being formed from a spherical zone delimiting the spherical layer on the outside, possibly a cylinder adjoining it on both sides and a cylindrical bore penetrating the aforementioned arrangement perpendicularly and coaxially to the small circle diameter of the spherical layer and corresponding to the inner diameter of the pipe.

A housing 1 (Figure 1) consists of a housing shell 1a and four connecting pieces 2.1 to 2.4 evenly distributed around its circumference, as well as a first and a second pipe socket 3* and 4*, respectively, which are arranged on both sides of the housing shell 1a in the direction of the pipe axis A. Each of the connecting pieces 2.1 to 2.4 delimits an associated housing opening 2.1a to 2.4a and thus creates an access option into the interior of the housing 1. At the end of each connecting piece 2.1 to 2.4, an associated clamping piece 2.1b to 2.4b is formed, via which, in connection with a corresponding clamping piece on the measuring or control device, the latter is fastened in the respective receiving connecting piece. A cylindrical bore B marked on the pipe socket 4* corresponds to the inside diameter of the pipeline receiving the housing 1; This bore B continues unchanged and seamlessly in the housing shell 1a into the second pipe socket 3*.

The illustration according to Figure 1 , in conjunction with Figure 4, which shows by way of example the creation of a housing 1 with six connecting pieces 2.1 to 2.6, makes it clear that the housing shell 1a, the four connecting pieces 2.1 to 2.4 arranged on it and the first and second pipe pieces 3*, 4* arise from an extended base body G* with the length L(G*), which is formed from a symmetrical spherical layer K, cylinders S1, S2 adjoining on both sides and in the direction of the pipe axis A, and the cylindrical bore B penetrating this arrangement perpendicularly and coaxially to the small circle diameter D. In Figure 1, only the correspondingly marked partial surfaces Z remain of a spherical zone Z delimiting the spherical layer K on the outside. The radius R (Figure 4) of the spherical zone Z is dimensioned such that the latter at least envelops the fully formed connecting pieces 2.1 to 2.4. The axial extension L _min (K) of the spherical layer K results geometrically from the distance of the intersection points between the radius R and the outer diameter (equivalent to the small circle diameter D) of the first and second pipe sockets 3* and 4* respectively.

Figure 4 further makes it clear that under the aforementioned conditions, it is easily possible to machine the four connecting pieces 2.1 to 2.4 out of the full base body G or the extended base body G*, and that due to the spherical shape of the base body G, G* on the outside, the respective connecting pieces 2.1 to 2.4 can be machined out relatively easily by means of a cutting tool rotating in a plane perpendicular to the axis of the respective connecting pieces 2.1 to 2.4.

The geometric relationships are even clearer in Figure 3, which shows a housing 1 equipped with six connecting pieces 2.1 to 2.6. Of the original base body G, only the partial surfaces of the spherical zone Z that border the spherical layer K on the outside remain. The flat outer surfaces 2.1c to 2.6c that arise when the respective connecting pieces 2.1 to 2.6 are machined out of the housing shell 1a (see also Figure 1 in this regard) form the shell surfaces of a prismatic

083GM1A0 ..

25.10.1999 .:..·..·

Body with hexagonal cross-section. The figure also shows clearly which axial extension a first and a second pipe connection 3, 4 receive if the radius R of the spherical zone Z delimiting the spherical layer K on the outside is dimensioned as shown in Figure 4 and if the spherical layer K is turned to the small circle diameter D on the outside diameter of the clamping sockets 2.1b to 2.6b in accordance with the indicated contour a1 and a2.

While the relatively short pipe connections 3, 4 are still contained in a spherical layer K with the axial extension L _mri1 (K), the relatively long pipe sockets 3* 4* can be provided on the housing 1 without the need for a respective weld seam if the extended base body G* with the length L(G*) is selected as the starting body. This results, as already shown above in connection with the first embodiment according to Figure 1 with reference to Figure 4 , when the base body G is supplemented on both sides and in the direction of the pipe axis A by the cylinder S1, S2, wherein the diameter of the cylinder S1, S2 corresponds to the small circle diameter D and its length corresponds to the length of a pipe socket 3*, 4*. The extended base body G* has the jacket contour S1-Z-S2 on the outside, which is relatively easy to produce by turning.

In the embodiment according to Figure 3, with the specified nominal diameter of the pipeline and the selected nominal diameter for the connecting pieces, a maximum of six of these connecting pieces 2.1 to 2.6 can be provided. The number is determined by the larger required minimum distance between adjacent connecting pieces, which results from the space required either for machining the respective connecting piece out of the base body G, G* or for two adjacent connecting elements (joint clamp of the clamp connection or union nut of the pipe screw connection).

When producing individual housings according to the innovation or in small series production, it is economical to use the base body G or the extended base body

· r··

083GM1A0

per G* from a full spherical layer K. The starting material for the base body G, G* is then preferably rod material with an outer diameter that corresponds to the outer diameter of the spherical zone Z.

For series production, the base body G, G* is advantageously machined from a centrifugally cast part with the spherical zone Z formed on the outside, possibly with a cylinder S1, S2 adjoining on both sides and a central, essentially cylindrical bore oriented in the tube axis A, taking into account a machining allowance.

The result of applying the innovation to a housing 1 with two connection nozzles 2.1 and 2.2 is shown in Figure 2. This housing configuration was the preferred one to date, since it could previously only be manufactured in this two-pipe form with reasonable effort and by means of the two manufacturing processes described above.

Figures 1 to 3 show the preferred design of the connecting pieces 2.1 to 2.6 with regard to their connection to the associated measuring or control devices. These are so-called clamp flanges 2.1b to 2.6b for a clamp connection, as defined in DIN 32676. However, it is also possible to provide a so-called threaded piece 2.1b* to 2.6b* of a pipe screw connection, as defined in DIN 11864, instead of the aforementioned clamp flange 2.1b to 2.6b. The design criterion for the radius R of the spherical zone Z then arises in the same way as can be seen by way of example for a clamp flange 2.1b, shown in Figure 4 .

Claims (7)

1. Housing for the installation of measuring and control devices, in particular one with inline suitability, which can be integrated into a pipeline, which consists of a housing shell with two pipe connections, which are arranged on both sides of the housing shell in the direction of the pipe axis, and which has at least one connection piece oriented in a plane perpendicular to the pipe axis, in the radial direction and arranged centrally on the outside of the housing shell, in which the measuring or control device is accommodated without forming a sump or dome and is fastened by means of a clamp connection or pipe screw connection, characterized in that 1. that the housing shell ( 1a ), the connecting pieces (2.1 to 2.n) arranged on it and the first and second pipe connections ( 3 , 4 ) emerge from a base body (G), 2. which consists of a symmetrical spherical layer (K) and 3. a cylindrical bore (B) is formed which penetrates the spherical layer (K) perpendicularly and coaxially to its small circle diameter (D) and corresponds to the inner diameter of the connected pipeline, 4. wherein the radius (R) of a spherical zone (Z) delimiting the spherical layer (K) on the outside is dimensioned such that the latter at least envelops the fully formed connecting pieces (2.1 to 2.n). 2. Housing according to claim 1, characterized in that the base body (G) is supplemented on both sides and in the direction of the pipe axis (A) by a cylinder (S1; S2) to form an extended base body (G*), and that the diameter of the cylinder (S1; S2) corresponds to the small circle diameter (D) and its length corresponds to the length of a pipe socket ( 3 *; 4 *). 3. Housing according to claim 1 or 2, characterized in that two or more connecting pieces (2.1 to 2.n) are provided, which are arranged evenly distributed over the housing shell ( 1a ), and that the maximum possible number of these connecting pieces (2.1 to 2.n) is determined by the larger required minimum distance between adjacent connecting pieces, which results from the space required either for machining the respective connecting piece out of the base body (G; G*) or for two adjacent connecting means (articulated clamp of the clamp connection or union nut of the pipe screw connection). 4. Housing according to one of claims 1 to 3, characterized in that the base body (G; G*) is made of solid material, preferably of cylindrical rod material. 5. Housing according to one of claims 1 to 3, characterized in that the base body (G; G*), taking into account a machining allowance, is made from a centrifugally cast part with the spherical zone (Z) formed on the outside, optionally a cylinder (S1; S2) adjoining on both sides and a central, essentially cylindrical bore oriented in the tube axis (A). 6. Housing according to one of claims 1 to 5, characterized in that a clamping socket ( 2.1 b) of a clamping connection is formed on each connection socket (2.1 to 2.n). 7. Housing according to one of claims 1 to 5, characterized in that a threaded socket ( 2.1 b*) of a pipe screw connection is formed on each connection socket (2.1 to 2.n).