WO1981002461A1

WO1981002461A1 - Method and means for the connection of a branch pipe to a previously fixed pipe line

Info

Publication number: WO1981002461A1
Application number: PCT/SE1981/000053
Authority: WO
Inventors: T Baumbach
Original assignee: T Baumbach
Priority date: 1980-02-26
Filing date: 1981-02-26
Publication date: 1981-09-03
Also published as: SE8001502L; SE425185B

Abstract

Method and means for connection of a branch pipe to a pipe line through a valve (1, 2), in doing which the valve is connected to the line pipe in such a manner that its flow channel (8) is directed tangentially towards the line pipe (9). By means of a cutting tool (12, 20) applied to the valve's outlet (15) an opening can be cut in the line pipe (9) through the open valve (1, 2). After the closing of the valve, the tool is dismounted and the branch pipe is connected in its stead.

Description

METHOD AND MEANS FOR THE CONNECTION OF A BRANCH PIPE TO A PREVIOUSLY FIXED PIPE LINE

TECHNICAL FIELD

The present invention relates to a method and means for connecting a branch pipe to a previously fixed pipe line through a valve, the valye being of such a construction that it in open position shows a straight flow channel, preferably a valve of ball or plug type. More particularly the invention is adapted for connecting branch pipes to pipe lines in systems filled with fluid or gas.

BACKGROUND ART A number of methods and pipe connecting means for connecting a branch pipe to pipe lines through valves in systems filled with fluid or gas are known. According to one method, described in the Swedish patent No.7317194-4, a pipe connection means comprising two connection parts is applied to a previously fixed line pipe in a seaiing relationship, o-ne of the connection parts having a guiding channel in which a piston provided with a transversely extending flow hole under the influence of an applied power can be moved towards the previously fixed line pipe, thus cutting an opening in the pipe with its edge formed end portion. The transversely extending flow hole in the piston serves as a flow communication between the previously fixed line pipe and the branch pipe which is to be connected by means of the pipe connecting means. Owing to the fact that the piston is rotatable the flow communication can be adjusted or if necessary cut off completely.

The known methods and the pipe connecting means developed in order to realize these methods are affected with disadvantages. Thus the piston in the example mentioned above works as a cutting tool and for that reason at least the cutting edge must be made of steel. As the piston is intended to be used as a valve body after the hole has been cut and thus has to be left in the connection means, the cutting edge, with regard to the corrosion risk, must be made of a high-test stainless material when used on copper pipes. In this way the piston becomes expensive regarding material as well as making. Furthermore it is required that both the surface of the guiding channel and the envelope surface of the piston are given high surface smoothness at the manufacturing and that there is a close running fit between the piston and the guiding channel in order to obtain an effective cut off of the flow communication to the branch pipe. This requirement of precision at the manufacturing makes such a connection means considerably more expensive

DISCLOSURE OF INVENTION

The present invention serves the purpose of eliminating these disadvantages, and of providing a simple and safe method in addition to simple and less expensive means for connecting a branch pipe to a previously fixed pipe line through a valve even if the pipe line when connecting is filled with fluid or gas.

This is achieved thereby that the method and the means according to the invention have been given. the characteristic features stated in the below mentioned claims.

The invention. will be more fully described below, in connection to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows in section a ball valye according to the preferred embodi ment of the method, said ball valve being connected to a pipe line.

Figure 2 is a sectional view of a ball valve connected to a pipe line and of an embodiment of a hole cutting tool for the realization of the method, the hole cutting tool being applied to the outlet of the ball valve.

BEST MODE FOR CARRYING OUT THE INVENTION

The ball valye shown in Figure 1 comprises a housing consisting of two parts 1 and 2 which housing encases a ball 3 provided with a through hole. The ball, which is fitted between two stuffing washers 4 and 5 is provided with a recess 6, reachable from the outside if a plug 7 is removed. By means of a tool adapted to its purpose the ball can be rotated in order to adjust or cut off the flow in the flow channel 8. Several plugs 7 with corresponding recesses 6 in the ball can be arranged in the valye housing making it possible to operate the ball from the side which has the best accessibility. The housing part 1 is formed as a pipe connection that encases the pipe 9 shown in cross section and to which the housing is tightened by means of the clamp 10. The outlet 11 of the valye is arranged in a connection piece 15 located in the housing part 2 and to which the not shown branch pipe is to be connected.

The housing part 1 is arranged in such a manner that when encasing the pipe 9 a portion of the pipe extends into the flow channel 8. By inserting a cutting tool in the flow channel 8 it is possible to cut an opening in the pipe portion encased by the housing. The cutting tool has been given the shape a piston, the shown end portion 12 of which being provided with a cutting edge 13. The piston is so dimensioned that, during the cutting operation, it is fully guided by the flow channel 8. By the shape of the piston the cut out portion 14 of the pipe is unfolded in front of the piston and, if the cutting operation is interrupted before the portion 14 is separated from the pipe, it can be left in the flow channel where it only to a negligible degreee obstructs the flow of gas or fluid in the branch pipe.

Figure 2 shows an embodiment of a hole cutting tool, which is designed in such a manner that the cut off portion of the line pipe is caught by the piston and removed together with the tool after completed cutting operation. which operation can be done even if the pipe line is filled with gas or fluid. The tool comprises a tubular housing 16, in which a piston 12 is arranged so that it can be moved between two terminal positions. With the piston 12 in a rear terminal position the piston projects so much outside the housing, that it inserted into the outlet of the valve does not fully reach the ball 3 when the tool is applied. The tool is applied to the valye by means of a nut 17 arranged around the one of its end portions, the nut engaging the screw thread of the connection piece 15. In the tool housing 16 two longitudinal diametrically opposed slots 18 are arranged through which the end portions of a follower pin 19 protrude, the follower pin being arranged in a through hole in the rear end of the piston. In the front end portion of the piston 12 a part of the piston has been removed and partly replaced by a separate cutter 20, which is attached to and partially surrounds the remaining curved part 21 of the piston end.

By means of the follower pin 19 the piston can be moved through the flow channel 8 until the cutter 20 reaches the line pipe 9. With the piston in this position the nut 22 can be engaged to a screw thread 23 arranged around part of the housing 16 and by tightening the nut the follower pin 19 is actuated and the piston is advanced to a front terminal position, the cutter 20 thus cutting an opening in the line pipe. The cut off portion of the line pipe is thereby forced into the gap 24 between the curved part 21 and the cutter 20 where it is bent in such a manner that it is caught in the gap 24 and accompanies the piston when this after the cutting operation is brought back into the rear terminal position. In case the line pipe is gas or fluid filled the valve is closed by rotating the ball until its through hole comes crosswise the flow channel 8 before the cutting tool is removed. The stuffing washer 25 and the packing ring 26 prevent gas or fluid from passing the tool and the quantity of gas or fluid that after the valve has been closed remains in the outlet and mostly is lost when the tool is removed is of no practical importance.

In order to make sure that the cut off portion of the pipe is caught by the piston at all occurring wall thicknesses of actual line pipes the cutter 20 for instance can be arranged to be moved in relation to the ciirved part 21, having a spring arranged in the piston which at ceasing resistance of cutting pushes the cutter ahead and squeezes the cut off portion towards the curved part 20. When the cutting tool has been dismounted from the valye the cut off portion is easily removed by being pushed aside out of the gap 24.

The shown cutting tool can easily be changed to fit different types of power acting against the piston. If the slots 18 and the follower pin 19 are eliminated, it is for instance possible to arrange an explosive cartridge or a connection to a hydraulic pump in the end portion 27.

The tool also comprises not shown guiding arrangements which secure that the cutter 20 is in correct position in relation to the pipe 9.

Through the proposed method it is achieved that the demands for accuracy of manufacture concerning the piston and the guiding or flow channel can be lowered at the same time as the risk of destroying the sealing function of the valve is eliminated. The method also makes the connection of branch pipes cheaper due to the fact that the same cutting too' can be used for making a lot of connections instead of each connection means using its own cutting tool as the case is with known connection means.

Claims

1 CLAIM:

1 Method for the connection of a branch pipe to a previously fixed pipe line through a valve, the valve being of such a construction that it in open position shows a straight flow channel, preferably a valve of ball or plug type characterized in a) the valve being applied at the line pipe by means of a connection part, which entirely or partly encloses the line pipe in one against the flowing medium of the pipe line sealing relationship, the flow channel of the valve being preferably directed tangentially towards the line pipe, a cutting tool comprising a piston or the like provided with a cutting edge, being thereafter or earlier applied in a sealing manner to the outlet of the valve, b) the piston being moved forwards through the flow channel towards the line pipe and an opening being cut in the portion of the line pipe enclosed by the connection part c) the piston being restored and the valve being closed d) the tool being dismounted and the branch pipe connected to the valve outlet e) the valve being opened fully or only partly for adjustment of the medium flow of the branch pipe.

2 Valve for realizing the method according to claim 1 comprising a housing (1, 2) in which a valve body (3) provided with a through hole is arranged for adjustment or closing of a flow through a flow channel (8) connecting the in and outlet openings, the valve body having the form of a plug, ball, slide or the like characterized in that its inlet side is arranged to entirely or partly enclose the line pipe (9) in such a manner that this partly and preferably in tangential direction runs through the flow channel.

3 Tool for realizing the method according to claim 1, characterized in that it comprises a tubular housing (16), means for applying the housing to the valves outlet side given the shape of a connection piece

(15), the housing forming an extension of the flow channel (8), an axially movable piston (12) or the like arranged in the housing, a cutting edge or cutter (13, 20) arranged on the piston at its end portion turned against the valve, means (19, 22, 23) for the moving of the piston into the flow channel, in doing which the cutting edge (13, 20) can be forced to cut an opening in the portion of the pipe enclosed by the valve or cooperative connection parts.