RU2308365C1 - Device for repairing drill pipe - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: device comprises members for storing, feeding, and charging pipes, resurfacing head mounted for permitting linear and angular zenith deviation, and conducting pipe supports whose plus terminals are connected with the pipe. The minus terminal of the power source is connected with the electrodes. The electrodes are mounted in the welding head to define a row parallel to the axis of the pipe for permitting the change of the distance between them. The unit for longitudinal motion of the electrodes is made for permitting simultaneous feeding of flux to the zone of resurfacing. The device is provided with a member for supplying air into the pipe, cooling rings, and devices for temperature control of the sites of resurfacing.

EFFECT: expanded functional capabilities.

4 dwg

Description

The invention relates to welding and surfacing and may find application in the restoration of worn parts of parts such as bodies of revolution, in particular drill pipes.

A known unit for surfacing cylindrical products, including a power drive, a surfacing apparatus, a hopper with a flux, a mechanism for longitudinal and transverse movement of the surfacing apparatus, a rotation mechanism of the roll, a cutter for removing flux residues, a device for collecting flux residues, thermocovers and gas burners located under the roller . The thermal jacket has removable arch sections, and the number of gas burners is even, one half of these burners has a gas supply from the front headstock of the roll rotation mechanism, and the other half has a gas supply from the tailstock side (RF Patent No. 2056234, CL V23K 9/04 , published. 1996.03.20).

The known unit does not provide high-quality surfacing of cylindrical products of small radius.

Closest to the proposed invention in technical essence is a device for surfacing parts having the form of bodies of revolution. In the device, the surfaced parts are fixed in supports with a rotation drive. The welding head includes an electrode wire feed mechanism, a flux hopper, a unit for longitudinal, horizontal and vertical movements of the welding head. The removable carousel is made in the form of two vertical, parallel faceplates installed in the supports located below the rotation drive. In the carousel plates, “n” is made equally spaced from the axis of the horizontal shaft, uniformly spaced along the circumference of the coaxial holes for fixing “n” of alternately deposited parts. The plates are mounted on a horizontal shaft with the possibility of rotation and alternating location of the next surfaced part in the extreme upper position of the rotation drive shaft. The device has a horizontal mounting platform of variable height, which is movably located under the additional supports (RF Patent No. 2277460, CL V23K 9/04, published. 2006.06.10).

The known device allows surfacing on heavy parts with high performance and with an increase in the convenience of work. However, the device does not provide high-quality surfacing on pipes of small diameter with a small wall thickness.

The proposed invention solves the problem of creating a device for surfacing on pipes of small diameter with a small wall thickness, in particular on drill pipes.

The problem is solved in that in a device for restoring a drill pipe, including supports, a rotation drive, a surfacing head, an electrode feeding mechanism, a flux hopper, a longitudinal, horizontal and vertical movement unit for the surfacing head, pipe storage, feeding and overloading units, according to the invention, the surfacing head is made with the possibility of a linear and angular deviation from the “zenith”, the pipe supports are made with current-supply connecting a “plus” to the pipe, a “minus” from the source of electric current is connected to the electrode mi, all the electrodes for surfacing the nipple part of the pipe are powered from one source of electric current, all the electrodes for surfacing the coupling part of the pipe are powered from the second source of electric current, the electrodes are installed in the welding head in a row parallel to the axis of the pipe with the possibility of changing the distance between the electrodes, the movement of the electrodes is performed with the ability to supply flux, the device is equipped with an air supply unit inside the pipe, cooling rings of the pipe ends and devices for temperature control of the surfacing places.

SUMMARY OF THE INVENTION

Restoration of the worn-out surface of the pipes by surfacing extends the service life of the pipes and allows you to refuse to purchase new lots of pipes instead of worn-out ones. However, the surfacing process especially of pipes of small diameter and small wall thickness is not always highly productive and efficient. The proposed invention solves the problem of surfacing on pipes of small diameter with a small wall thickness, in particular on drill pipes. The problem is solved by the device for the restoration of the drill pipe, shown in Fig.1-4.

A device for restoring a drill pipe 1 consists of a base 2, a drive for pipe blanks 3, a drive for finished products 4, pipe carriers 5, a pipe rotator 6, roller bearings 7, a self-propelled carriage 8 with an installation for surfacing the sleeve part of the drill pipe 9 and a nipple surfacing installation drill pipe parts 10.

Roller bearings 7 of the pipe 1 are made of current-carrying with the connection of a “plus” to the pipe 1 and equipped with copper-graphite brushes 11 and a flexible current-carrying bus 12.

Installation for surfacing both the coupling and nipple parts of the drill pipe 1 consists of guides 13 and a welding-surfacing machine 14, including an electric current source 15 with a remote control 16, a surfacing head 17, a feed mechanism 18 of electrodes 19, a mounting mechanism of 20 electrodes 19, a mechanism oscillations of the surfacing head 21, dressing device for electrode wire 22, hopper 23 for flux 24 and flux-feeding device in the form of tubes 25 and funnels 26. In the lower part of pipe 1, a flux-retaining device 27 is mounted in the form of a series of elastic wires, s schemlennyh at one end and is elastically biased to the tube 1.

The surfacing head 17 is made with the possibility of placing the electrodes 19 in a row parallel to the axis of the pipe 1 with adjustable distance between the electrodes 19 and with the possibility of a linear "A" and angular α deviation from the "zenith". The "minus" from the source of electric current 15 is connected to the electrodes 19. All the electrodes for surfacing the nipple part of the pipe are powered from one source of electric current, all the electrodes for surfacing the coupling part of the pipe are powered from the second source of electric current.

The movement of the electrodes 19 is made with the simultaneous supply of flux 24.

The rotation to the pipe 1 is transmitted from the rotator 6 by means of tongs 28 abutting against the walls of the pipe 1 from the inside.

A compressed air source 29 is supplied to the device to supply air into the pipe 1 for cooling. The device is equipped with a heat-resistant heat-insulating fabric for temperature control of the ends of the pipe 1 after surfacing. To cool the ends of the pipe 1 and hold the flux 24, the rings 30 are pressed against the ends by the hollow plugs screwed into the threads of the pipe 1 (not shown).

The feed mechanism 18 of the electrodes 19 is designed to feed the welding wire into the weld zone. The mechanism consists of a drive and levers with pressure rollers, pressing the wire to the feed rollers.

The device for editing the electrode wire 22 consists of feed and receiving sleeves, receiving and clamping rollers, passing through which the electrode wire is straightened.

The installation mechanism 20 of the electrodes 19 allows for a linear deviation of the electrodes 19 from the "zenith". For angular deviation from the "zenith" surfacing head 17 is fixed to the bracket with axial or ball mount.

The device operates as follows.

Drill pipes 1 are placed in the pipe blank drive 3 and are to be restored. With the pipe carrier 5, one pipe 1 is loaded onto the surfacing workstation and installed in the roller bearings 7. The welding wire is refilled, the position of the electrodes 19 is adjusted, the flux supply is checked, the flux-retaining devices are installed, the rotator 6 is fixed in the pipe 1. The electrodes 19 are displaced in a horizontal plane of symmetry against the direction of rotation of the pipe 1 with a linear deviation from the "zenith" by 20-30 mm and an angular deviation from the "zenith" by 18-26 °, adjust the amplitude and frequency of oscillation of the electrodes 19 on the oscillating mechanism and development or control of surfacing modes.

When restoring the drill pipe 1, an automatic arc surfacing is performed under the submerged arc 24 on the surface of the worn part of the pipe 1 of the weld bead from longitudinal sections located along the pipe 1. The surfacing is carried out in direct polarity with a minus on the electrodes 19 and a plus on the pipe 1. All electrodes 19 for surfacing the nipple part of the pipe are recorded from one source of electric current, all electrodes 19 for surfacing the sleeve part of the pipe are electrically powered from the second source of current. Powering a group of electrodes from a single current source contributes to the equalization of the melting of the electrodes, their uniform consumption. The formation of longitudinal sections is performed by moving the electrodes 19 in the forward and reverse direction along the axis of the rotating pipe 1. The distance between the electrodes 19 is chosen equal to the value of the movement of the electrodes 19 in the longitudinal sections along the forming pipe 1. The movement of the electrodes 19 is combined with the supply of flux 24. During the welding process, the pipe 1 is cooled from the inside by air supply and from the ends by installing copper rings 30 at the ends, which also serve to hold the flux 24 on the surface of the pipe 1. To protect the weld rapid cooling and drafts on each coupling and nipple before laying them in the store finished products put on thermostats made of heat-resistant material such as asbestos.

Surfacing is possible to perform both simultaneously and separately nipple and coupling parts.

Recovered pipes are loaded into the finished product storage 4.

For surfacing, a filler wire is used, for example, grade Np 30KhGSA with a diameter of 1.8-2.0 mm, cleaned of rust and contaminants, washed with white spirit or A95 gasoline; flux grade ФВТ-1, calcined for 3 hours at a temperature of 400 ° C, or flux 48-OF-10; asbestos cord diameter 6 ÷ 8 mm.

Worn out parts of the nipple and drill pipe couplings with worn tool part diameters up to 148 ... 150 mm are welded. In this case, the maximum thickness of the deposited layer is 16 mm per diameter, taking into account the allowance for subsequent machining. The width of the restored layer is not lower than 180 mm, on the coupling - 350 mm. Surfacing is carried out by three to four electrodes simultaneously. The distance between the electrodes is set equal to the amplitude of the oscillations.

Application of the proposed method will allow surfacing on thin-walled pipes of small diameter.

Claims (1)

A device for restoring a drill pipe overlay containing nodes for storing, supplying and reloading the pipe, supports for placing the pipe, its rotation drive, an air supply unit inside the pipe, rings for cooling the pipe ends and holding the flux, devices for thermostating the weld points located in the surfacing head a group of electrodes for surfacing the nipple part of the pipe, powered from one source of electric current, and a group of electrodes for surfacing the coupling part of the pipe, placed in another surfacing head and made from a second source of electric current, with each surfacing head installed with the possibility of linear and angular deviations from the "zenith" and its longitudinal horizontal and vertical movements and is connected to the electrode feeding mechanism to the surfacing head and flux hopper, supports for placing the pipe are made with current-supplying with connection “Plus” to the pipe, and “minus” to the electrodes, in each surfacing head the electrodes are installed in a row parallel to the pipe forming with the possibility of changing the distance between they, and the site of the longitudinal movement of the electrodes made with the possibility of simultaneous supply of flux into the weld zone.

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