DE2330872A1 - PIPE CONNECTION - Google Patents

Description

V allourec (Usine s a Tubes de Lorraine-Escaut et Vallourec Re u nies), 7 Rond Point Bugeaud, Paris 16 ^ m e, France

Pipe connection,

The present invention relates to pipe connections, especially on pipe connections for the petroleum industry

There are already connections for metal pipes, in particular steel pipes, in which the ■ screwing takes place by means of a thread which is provided on a conical surface at the end of the bolt tube, this thread engaging in a thread of corresponding shape, which is on a conical inner surface at the end of the mother pipe element is provided. In one embodiment, such a pipe joint, the gasket is obtained in that the end of the bolt tubular element abuts against a shoulder of corresponding shape for bearing, which is located at the base of GeVindes of Muttefrohrelementes, which shoulder rich in its central B _e of a conical, flachkonischen surface consists, whose free inner edge extends in the direction of the end of the nut pipe element, while the circumferential zone of the shoulder has an inverse conicity, which preferably has a steeply conical course, so that when the end of the bolt pipe element against the shoulder of the nut pipe element to abut comes, the central zone of this shoulder creates a tendency to spread the end of the bolt tube element, while the circumferential area of the shoulders serves as an abutment against such force effects. ·

The present invention relates to a variant embodiment the aforementioned connection, which makes it possible to obtain all the sealing properties of this connection without one editing with such a big one. Perform accuracy

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must, which is particularly important when connecting pipes with small Diameter has a beneficial effect

With the aforementioned known connections, it is necessary that the axes of the various machined surfaces of the bolt tube element and the nut tube element are precisely aligned with one another. In particular, any axial deviation in the machining of the various surfaces makes it difficult to achieve good sealing properties. These difficulties are much greater for pipes having a small diameter than in larger diameter pipes, because the inaccuracies of the processing inherent in the machine tool used, have the same absolute magnitude, while the relative influence of F _e hler increases with smaller diameter of the connection.

This problem is all the more important than it is in general must ensure the interchangeability of the bolt tube elements and the nut tube elements. This means that one must be able to screw together and loosen any bolt tube element with any nut tube element several times.

The present invention relates to a pipe connection made of steel pipes, as they are used in particular in the petroleum industry, the pipe elements of the pipe connection being screwable and releasable and the seal being achieved in that the end of the bolt pipe element can be pressed against a shoulder in the interior of the nut pipe element, whereby this shoulder consists of a central conical area, the free inner edge of which extends in the direction of the end of the bolt tube element, and a circumferential conical area, the conicity of which is oriented opposite to the conicity of the central area, and wherein the end of the bolt tube element has a shape, the said central predominantly of inputs serving Schraubbegrenzung B _e reaching the shoulder of the Mutterrohr-

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element corresponds and which is identical to the outer circumferential area of the shoulder of the mother tube element or adapted to this area. This pipe joint according to the invention characterized [in _t that the serving for screwing together of the pipe joint threads which lie on the outer surface of the bolt ro ^ relementes and on the inner surface of the parent pipe member een, partly in a cylindrical surface containing the major proportion of the total surface provided with a thread and, in the case of the nut pipe element, begins at its shoulder or, in the case of the bolt pipe element, at its end, partially advance on a conical surface which adjoins the cylindrical threaded surface

According to a further characteristic of the invention, the threads provided on the cylindrical surfaces of the bolt tube element and the nut tube element are designed in such a way that the screwing together takes place without significant friction and without a clamping effect _e winds floors of the parent pipe element or · between the screw heads of the parent pipe thread and the G _s thread "- soils remains of the bolt tube element.

According to a preferred embodiment of the invention, the threads provided on the conical surfaces of the elements of the connection are designed in such a way that, when the connection is tightened, they slightly clamp the end of the nut pipe element on the bolt tube element or vice versa.

According to another advantageous embodiment of the invention, the proportion of the surface which is covered by the conical G _e winds, in the order of 15 to 25 # of the area that is covered by the cylindrical thread, so that the effect of the cylindrical thread in Screwing together predominates

The dimensions of the ends of the bolt tube and nut tube elements are chosen so that a slight lateral

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Game between the outer surface of the bolt tube element and the front part of the nut tube element remains, so that the Bolt tube element can align itself on the shoulder of the nut tube element in order to effect both the seal as well as to find its screw-in limit on this shoulder,

The angle made by the generatrix of the central area of the shoulder of the nut pipe element with respect to a plane which is perpendicular to the axis of the pipe connection is greater than the sliding angle between the end of the bolt tube element and • the central zone of the shoulder of the nut tube element. This Glide angle is e.g. between 10 and 30 and is preferred set between 15 and 20 ° ".

The shape and the inclination of the outer peripheral zone of the mother pipe element may vary within fairly wide limits, depending in an as large extent this zone as a nip for the corresponding B _e reaching the end of the bolt tubular member serves to seal by means of elastic and / or plastic V _e rformung sure.

In a particular embodiment, the circumferential zone of the shoulder of the nut pipe element can be formed by a conical surface the generatrix of which, for example, forms an angle of 60 ° with a plane perpendicular to the axis of the pipe connections runs.

According to the invention the lateral play, which is rich between Bolzenrohr- and mother pipe member along the B _e of the connection is provided, which between the end of the conical G _e wind and the peripheral zone of the shoulder of the Mutterrobj> element runs, some tenths of a millimeter, for example, 0, 2 mm with a thread diameter of about 4-0 mm in the cylindrical thread area.

Thanks to the presence of play between the bolt tube * -

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element and the mother tube line the end of the bolt tube element the possibility of setting oneself exactly in the axis of the shoulder of the mother pipe element, even if slight deviations deviations in the direction of illumination between the end of the bolt tube element and the mother pipe element.

As you can see, it is thanks to the invention possible an exact coincidence between the B _e processing sachse the shoulder of the female tubular element and the machining axis of the associated counter-surface to get at the end of the bolt tube element, because the latter has a sufficient lateral play and sufficient flexibility to to permit such coincidence to the extent that the lateral play of the cylindrical threads permits such lateral movement.

This advantage is particularly pronounced in connections of Small-diameter pipes, for which a given machining tolerance takes on a relatively more significant value than for Larger diameter pipes

In addition, smaller diameter due to the attachment of the cylindrical G _e wind on the larger part of the total extension of the thread is avoided to a great reduction of the thread diameter in the case of tubes, what constitutes a further advantage. You can thus gain a larger cross-sectional area for the screw-in limitation in order to increase the resistance of the connection to screwing forces.

In a particular embodiment of the invention, the on the conical surfaces provided thread areas on threaded heads or threaded bases, which are given by generators, which all run parallel to the axis of the pipe connection.

The rear flanks of the threads of the thread of the nut pipe element are in a preferred embodiment under one

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Beveled angle, for example 45 with respect to the Pipe axis is to allow the introduction of the bolt pipe into the courage tube element to facilitate what is particularly important at the beginning of the screwing-in process has a favorable effect.

According to the invention it is possible to produce a pipe connection, in which one tube is a bolt tube end and the other tube is a nut tube end; but it goes without saying that the invention can also be applied to two pipes with bolt pipe ends which are screwed into a sleeve that carries two nut pipe ends of the invention

For a better understanding of the invention, it will be used in the following illustrated using an exemplary embodiment in the accompanying figures.

Figure 1 is a schematic sectional view through the end a bolt tube element according to the invention;

Figure 2 is a schematic sectional view through the end a corresponding nut pipe element;

Fig. 3 is a sectional view through a pipe joint using the elements of Figs. 6 and 2;

Fig. 4 is a · Sclmittbild which the Bo 1 on an enlarged scale, the thread in the cylindrical B _e reaching zenrohr- and the mother tube member;

Fig. 5 illustrates schematically in section the conical Threaded areas of the bolt tube and the nut tube element when screwed together.

In FIGS. 1, 2 and 3, the ends of the bolt tube element 1 and of the nut tube element 2 can be seen. The connection of the two elements is formed by a partly cylindrical, partly conical G _e thread 3 causes on the outer peripheral surface of said bolt pipe element, which engages in a partly cylindrical, partly conical thread 4, on the inner surface of the end of de. ^c

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Nut pipe element 2 is provided.

In FIGS. 1, 2 and 3, zone I illustrates the cylindrical and zone II the conical G _n thread region.

The inner shoulder 5 <3es mother pipe element 2 has the central B _e on rich 5a shows a conical shape, with the free edge of the conical portion extends toward the end of the mother tube member 5a. The conicity of this central area is, for example, 20 ° and thus corresponds to the angle between the generatrix of this conical area with a plane which runs perpendicular to the pipe axis.

The outer circumferential zone 5fr of the shoulder 5 can also be seen from the aforementioned figures. According to a special guide shape, the circumferential zone 5t) has a conical shape on, wherein the cone thus formed tapers towards the interior of the nut tube element and is illustrated in the Trap has a taper of about 6O, w / as the angle between is the generatrix of this conical area with a plane perpendicular to the axis of the tube.

From Fig. 2 also shows how the peripheral portion 5ΐ> of the shoulder 5 is ^a n G _e thread 4- over an area 6 is connected.

The end of the bolt tube element has a stop surface odea? Opposite shoulder? A, the shape of which corresponds to the shape of the area 5a of the shoulder 5 of the nut pipe element. This abutment surface ^7a of the bolt tubular element consists outwardly in an area 7t> fort, which comes against the peripheral area of the yo shoulder 5 of the mother pipe member into abutment.

The sealing surface 7b of the bolt pipe member connects to the thread 5 by a Z _w ischenflache 8 at.

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From Fig. 3 »which the two pipe elements illustrated in the assembled condition, it can be seen how the check-stop surface 7a of the bolt tubular element is ^a shoulder of the mother tube member to bear against the central portion 5, while the surface 7b ^a t the end of the bolt tubular element against the outer circumferential zone of the shoulder 5 of the nut pipe element presses »

One can also see the lateral play from FIG. 3, which exists between surfaces 6 and 8.

Incidentally, it is clear that the external surface area is 7 £> end of the bolt tubular element between the thread 3 and the · Einschraubbegrenzungsflache 7 ^a not a G _e must have Stalt, that exactly matches with the opposite corresponding surface of the mother tube element ·

So this surface of the bolt tube element can be screwed together suffer a permanent or a purely elastic deformation when they come against the corresponding sealing surface of the mother pipe element when it comes to concern.

Moreover, it is not necessary that the surface of the bolt tubular element disposed between the surface ^7a and the thread is located, in its entire length abuts against the opposite surface of the mother tube member.

In FIG. 4, the cylindrical G _e thread 3 and 4 of the two connecting members are illustrated in an enlarged scale.

The G _e thread heads ^3a and the G _e thread bottoms 3b of the thread 3 of the stud pipe member as well as the G _e thread heads 4 a and G _e Winder bottom 4b of the thread 4 of the mother tube member are also from Fig. H- visible.

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To ensure a frictionless screw connection of the cylindrical threads— To enable areas, the following geometric conditions must be observed:

a) The front flank and the rear flank of each G _ß thread turn must have a small opening angle to a plane that runs perpendicular to the axis of the thread _o In Fig. 4, the angle A is illustrated, which the front flank of the thread forms with the perpendicular to the pipe axis while the angle is designated by B _e zugsziffer B enclosed by the rear flank of the thread with the perpendicular to the pipe axis. In a special embodiment of the invention, the angle A is around 3 ° while the angle B is around 10 °.

b) The winds G _e * heads 3 of the bolt tube member lie on a diameter which is smaller than the diameter of the thread bottom 4b of the mother tube member is.

c) The winds G _e heads 4a of the mother tube member lie on a diameter> of the bolt tubular member is greater than the diameter of the thread root 3 * "

In this W _e ise is obtained a cylindrical thread which can be without any appreciable forces screw and allows a small lateral displacement of the pin tubular element inside the mothers tubular member, whereby the end of the bolt tube to center itself accurately on the shoulder of the female tubular element _e

Ih the embodiment shown in Fig. 4, the rear flanks of the gears G _e thread of the internal thread 4 at the position 4c chamfered. The bevel given by the angle G _f in this exemplary embodiment is 45 °. However, this is by no means a necessary feature.

In Fig. 5 is the conical threaded part of the bolt tube and

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of the nut tube element shown screwed together. In the right part of the figure, the transition from the conical thread zone II to the cylindrical thread zone I is illustrated, of which a section is shown.

The conicity of the conical threaded area G _e with respect to the axis of the tube is in this case

As can be seen from FIG. 5, the threaded heads 9a run and the threaded bases 9b of the nut pipe element as well as the Threaded bases 10b of the bolt tube element on surfaces whose generatrices are oriented parallel to the tube axis. In this way the entire machining of the thread can be done with one and the same tool.

As can also be seen from FIG. 5, the threaded heads are 10a of the bolt tube element thread with regard to the taper of the thread cut into a cylindrical surface slightly tapered.

In the particular embodiment illustrated in FIG the rear flanks 9o of the thread are also beveled, to facilitate the introduction of the external thread of the bolt tube element into the internal thread of the nut tube element »

The Bereiok, which the face of the nut rotating element end with connects the thread, also has a bevel 11, which in the illustrated case is an angle of 20 with the pipe axis forms. This bevel also serves to facilitate the introduction of the bolt tube element into the mother tube. element.

It goes without saying that the embodiment described above no limitation of the scope of the invention

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represents and that all desirable changes can be made without departing from the scope of the invention '·

In particular, the clamping that takes place in the conical thread part can be selected as a function of the torque which is considered to be desirable for the loosening of the connection

With regard to the meaning of the cylindrical thread is noted that the limitation of the screwing element of Bolzenrohr- exclusively under the action of counter-shoulder takes place, which is tubular element against the inner shoulder of the parent pressed _o It follows from the fact that the torque with precision the screw-in limitation, the size of which still depends on the coefficient of friction. The clamping effect of the conical thread area II therefore serves primarily to eliminate the disadvantageous effect of vibration, rotation and bending processes on the strength of the screw connection.

Claims "

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Claims (10)

η s ρ γ üehe Λ ) Pipe connection for steel pipes, especially for use in the petroleum industry, the pipe elements of the pipe connection being screwable and detachable and the seal being achieved in that the end of the bolt pipe element sweeps a shoulder inside the nut pipe element, whereby this shoulder can be pressed from a central conical area, the free inner edge of which extends in the direction of the end of the bolt tube element, and a circumferential! conical area, the conicity of which is oriented opposite to the conicity of the central area, and wherein the end of the bolt tube element has a shape that corresponds to the central area of the shoulder of the nut tube element, which is mainly used for screw-in limitation, and which corresponds to the outer circumferential area of the shoulder of the nut tube element is adapted rich identical or relevant to B _e, characterized in that the serving for screwing together of the pipe connection thread (3 * ^ Oι which lie on the outer surface of the pin tubular element (1) and on 4EU inner surface of the mother pipe element (2) and partly on a cylindrical connecting area accounting for the larger proportion of the area total threaded and at Mutterrohr- element on its shoulder (5) or · starts at the bolt pipe member at the end thereof, some of which run on a conical surface which thread to the cylindrical G _e £ Smile Friend «, 2) pipe connection according to claim 1, characterized in that the screwing of the cylindrical thread (3 &, 3b; ^ a, 4-b) takes place with low friction and without clamping effect 3) A pipe connection according to claim 2, characterized in that in the cylindrical region (I) of the thread (3 »4-) © in slight play between the winch G _e heads (3a) of the bolt pipe member - 2 309881/0971 and the threaded bases (4-b) of the nut tube element and between the threaded bases (Jb) of the bolt tube element and the Threaded heads (4a) of the mother pipe element Lind in the area one of the flanks of the thread is provided. 4-) Pipe connection according to one of the preceding claims, characterized in "-marked, that when the connection is tightened, the leonian gov? ind areas (II) cause a slight jamming of the Effect the end of the nut tube element (2) on the bolt tube element (1). 5) Pipe connection according to one of the preceding claims, characterized characterized in that the surface, which is provided with a conical thread (9a, 9b; 10a, 10b), 15-25 $ the Surface which is provided with a cylindrical thread, 6) Pipe connection according to eiiiem of the preceding claims, characterized in that a slight, lateral play around the part of the outer surface (8) of the bolt pipe element (1) is provided between the area (? B) which is against the shoulder (5) of the parent pipe member for sealing comes into abutment and the G _e thread beginning of the bolt pipe element (1). 7) A pipe connection according to one of the preceding claims, characterized in that the angle formed by the generatrix of the surface of the central shoulder portion (5 ^a) of the Mutterrohr- element with a plane perpendicular to the · axis of the pipe joint is greater than the Sliding angle that the end region (7 ^) of the bolt tube element forms with the shoulder (5a), and that the aforementioned angle is between 10 and 30, preferably between 15 and 20 _o 8) Pipe connection according to one of the preceding claims, there- - 3 ORfGlNAt INSPECTK) frekennzeichr> et, ds.8 the rear PXa ¹ "Icon dor * '.τ-ν-Ί e des Muttorrohroler- ^ rtes Atrrchrä.rvir-er! ( ^{/ u} c) on' / ei U: ¹ ! das Eins ^ t ^ en of the "Rol ^ ern'ohrelementos (1) in las ^ t tubular element; (2) zi.i ^ ρΗ.πγ dos Si ^ schran ^ vo ^ rB ^^ to make it easier. 9) RohrvorbirdnT '. ·'? η? ο ¹ "eir.en d ^ r 'vorhorgöh.erdo by fokenn ^ ei ^^^ t, ds.3 d? ^." Srde ^ cs i- ^Tii ~ T; an Aiifwei + 'urf (1Ί) before ko ^ i ^^ her ^ orr. ^ or · "clio EinfiJhrunfc den Boi. 10) Rohrvorblnd'T ⁰ 'rsf ^{1 a} ^ ni n ^ - ^ previous Ar! ST> i? Üoho, thereby p-ekenrzoichnot that the threaded heads (° a, 10a) \ m <5 the Gowiridebboden (9b, 10b ) of the conical threads run on surfaces whose generators do not ^{extend parallel - 7 to the} pipe axis. 3 0 ^ 881/0971 GÄD