DE3032357C1

DE3032357C1 - Process for cutting a pipe fitting with a weld joint preparation

Info

Publication number: DE3032357C1
Application number: DE19803032357
Authority: DE
Inventors: Werner 6237 Liederbach Becker; Klaus 6113 Babenhausen Kowalke; Hans 6000 Frankfurt Tomenendal
Original assignee: Messer Griesheim GmbH
Current assignee: Messer Griesheim GmbH
Priority date: 1980-08-28
Filing date: 1980-08-28
Publication date: 1982-04-01
Also published as: NL8103470A; JPS5762860A

Description

50 - 550 abgeschaltet und auf der entsprechenden50 - 550 switched off and on the corresponding

gegenüberliegenden Seite wieder eingeschaltet wird. Ist dieser erste Schnitt vollendet, wird die Brennschneidmaschine in Richtung der Achse 12 um den Betrag der Wandstärke s unter Berücksichtigung des Anpassungswinkels a versetzt (Maß L, Fig. 1). Außerdem wird entgegen der Einstellung der Parameter für den ersten Schnitt, der Außendurchmesser des Anpassungsrohres (also d+2s, Fig. 1) als Basis für die Kurvenform benutzt Des weiteren wird der auf der Innenseite in der 0°-Position gewünschte Nahtöffnungswinkel an der Pendeleinrichtung fest eingestellt. Die Brennschneidmaschine wird dann, ohne daß geschnitten wurde, bis an die Kontur des ersten Schnittes herangefahren. Die Kurven der auf Innendurchmesser und Außendurchmesser bezogenen Schnitte treffen sich an Beginn und Ende der Zone II in Fig. 2. Jeweils an der Grenze von Zone I und Zone II wird der zweite Schnitt angesetzt und durchgeschnitten, bis der Schneidstrahl das Material auf der gegenüberliegenden Grenze der Zone I und der Zone II wieder verläß-:. Das Ergebnis eines Schnittes nach dem erfindungsgemäßen Verfahren zeigen F i g. 2 und 3. F i g. 2 veranschaulicht die perspektivische Darstellung eines solchen Schnittes. Deutlich ist die über ca. 2400 des Rohrumfangs reichende, auf den Rohrinnendurchmesser bezogene Zone I zu erkennen. In dieser Zone öffnet sich der Winkel der Schweißnahtvorbereitung nach außen (F i g. 3). In der folgenden Zone II, die jeweils etwa 300 des Rohrumfangs einnimmt und »freigeschnitten ist«, liegt die Schweißnahtöffnung innen und außen (F i g. 3). In der auf den Rohraußendurchmesser bezogenen Zone III ist schließlich die Schweißnahtvorbereitung nach innen hin offen (F i g. 3).opposite side is switched on again. Is this first one Cut is completed, the cutting machine in the direction of the axis 12 to the The amount of the wall thickness s is offset, taking into account the adjustment angle a (Dimension L, Fig. 1). In addition, contrary to the setting of the parameters for the first Section, the outer diameter of the adapter tube (i.e. d + 2s, Fig. 1) as the basis used for the curve shape. Furthermore, the one on the inside is in the 0 ° position The desired seam opening angle is permanently set on the pendulum device. The flame cutting machine is then moved up to the contour of the first cut without cutting. The curves of the cuts related to the inside diameter and outside diameter meet at the beginning and end of Zone II in Fig. 2. Each at the border of Zone I and zone II, the second cut is made and cut through until the cutting beam the material on the opposite boundary of Zone I and Zone II again reliable :. Show the result of a cut according to the method according to the invention F i g. 2 and 3. F i g. 2 illustrates the perspective view of such a Cut. The one that extends over approx. 2400 of the pipe circumference to the pipe's inside diameter is clear related zone I to recognize. In this zone the angle of the weld seam preparation opens to the outside (Fig. 3). In the following Zone II, each about 300 of the pipe circumference occupies and is "cut free", the weld seam opening is inside and outside (Fig. 3). Finally, in zone III, which is related to the pipe outer diameter the weld seam preparation is open on the inside (Fig. 3).

Diese Zone nimmt etwa 60° des Rohrumfangs ein (F i g. 2). Der Vorteil des Verfahrens ist, daß besonders in der für das Schweißen sehr kritischen 0o-Position (F i g. 1) ein großer Schweißnahtöffnungswinkel zur Verfügung steht.This zone takes up about 60 ° of the pipe circumference (FIG. 2). The advantage of the process is that especially in the 0o position, which is very critical for welding (F i g. 1) a large weld seam opening angle is available.

Bevorzugt wird das oben beschriebene Verfahren mit herkömmlichen Brennschneidmaschinen durchgeführt. The above-described method with conventional ones is preferred Flame cutting machines carried out.

Claims

Claim: Method for cutting a pipe fitting with a Welding joint preparation, characterized in that - initially one on the pipe inside diameter related adjustment cut is made, - then cutting torch and pipes in the direction of the pipe's longitudinal axis relative to one another by a pipe wall thickness (s # and fitting angle (oc) -dependent Dimension L = S tana are offset against each other and - then one on the pipe outer diameter related adaptation partial cut is carried out.

The present invention relates to a method of cutting a Pipe adaptation (cutting the pipe end of an adapter pipe so that this to the outer contour of a second pipe - main pipe - adapts) and a weld joint preparation.

When torch cutting large adapting tubes that are under a If the angle is to be connected (welded) to a main pipe, it is necessary to that in the area of the adapter tube that is easily accessible from the outside, there is an external one Weld joint is provided, while in the pipe area that is difficult to access from the outside a weld joint lying within the adapter pipe must be made.

It is well known that for an external weld joint a flame cut is required, which is related to the inside diameter of the pipe, while a flame cut is necessary for the weld joint located inside the pipe which is related to the outer diameter of the pipe.

To achieve the welding joint preparation described above with Flame cuts related to different pipe diameters are different Procedure has been proposed.

In the method according to DE-PS 26 16 522, during an adaptation flame cut (Cut that extends over the full circumference of the pipe), the torch movement first based on the outer diameter of the pipe and then during this cut the Continuous reference point from the pipe outside diameter to the pipe inside diameter changes.

This remains in the transition area from the outer diameter reference point on the inside diameter reference point due to the pipe wall thickness a material increase stand. This is done by a recut (cut that only affects the transition area extends) away.

In the method according to GB-PS 15 48 918, in contrast to the method according to DE-PS 26 15 522 two adjustment cuts, both of which are over the full Extend pipe circumference, carried out, the first cut on the outer diameter of the pipe is related. The second cut is superimposed on the first cut, wherein the cutting torch reference point is continuous in a first cutting area from the pipe outside diameter to the pipe inside diameter during the cut is changed, then the reference point - inside pipe diameter - in a second Cutting area is retained and then the cutting torch reference point in a third cutting area again continuously from the pipe inside diameter to the pipe outside diameter is changed.

In both processes, the cutting is continuous Change (shift) of the cutting torch reference point required, including additional ones Reference point changing devices are necessary.

The object of the present invention is to provide a method for cutting to create a pipe adaptation with a weld joint preparation that / those without a change in the reference point during cutting is sufficient. To solve this problem a method according to the characterizing part of claim 1 is proposed. It will first made an adjustment cut based on the inside diameter is. This is followed by a second partial cut, offset by a certain amount, the is related to the pipe outer diameter. The two different cuts are offset from one another in such a way that in the area in which the cuts overlap, In any case, material increases are avoided, so this area is »cut freely« will. In the method according to the invention, neither takes place during the first cut (as in DE-PS 26 16 522) during the second cut (as in the procedure according to GB-PS 15 48 918) a continuous change in the cutting torch reference point. This has the advantage that with a conventional tube cutting machine, so without an additional reference point changing device, the one described at the beginning Welding joint preparation is achievable.

Further advantageous features emerge from the following Drawing description.

In the drawings, FIG. 1 is a representation of Adaptation and main pipe, F i g. 2 a perspective view of the adaptation cut, F i g. 3 Weld joint cross-section of different zones of the illustrated in Fig.2 Adjustment cut.

The requirements for the preparation of welding joints are due to the spatial The structure of the pipes is far more difficult to fulfill than with flat sheet metal. The different Angle at which the wall of the pipe end of an adapter pipe 10 to a Main pipe 11 meets, and complicate the possibly very small adaptation angle os an even weld joint preparation is considerable. The following is a procedure for cutting a pipe end with welding joint preparation described.

First a normal adjustment cut related to the inner diameter d is made cut with set weld preparation and other usual parameters, the torch pendulum device when reaching a pivoting angle of approx.