RU136570U1 - STAND FOR PNEUMATIC TESTS OF THREADED PIPE CONNECTIONS - Google Patents

Abstract

1. A stand for pneumatic testing of a threaded pipe connection, including a bed, a crimping head, connected with a working medium supply system, characterized in that the crimping head is longitudinally movable, the working medium is air, and air is supplied only to the space limited by the end rubber sleeve installed inside the pipe threaded joint, the inner surface of the pipe threaded joint and the end face of the crimping head. 2. The stand according to claim 1, characterized in that the sealing of the threaded connection of the pipe is carried out in one movement of the rod of the pneumatic cylinder connected to a movable rod moving relative to the fixed rod in order to compress in the axial direction of the rubber sleeve and seal the space. The stand according to claim 1, characterized in that the compression ratio of the rubber sleeve sealing the inner cylindrical surface of the pipe can be adjusted by the length of the groove of the movable rod.

Description

The utility model relates to devices for testing pipe connections for leaks and can be used to test the internal air pressure for density (tightness) of threaded connections of tubing or tubing to determine the need for their restoration during construction or overhaul of oil and gas gas wells.

A well-known stand for hydraulic testing of pipes, consisting of a frame in which the test pipe is located on the guides, a movable cart on which is installed with a carriage with a plug, a second carriage with a sealing head and a device for supplying test fluid, search mechanisms, centering, fixing the pipe and loading (patent for invention No. 27704, IPC G01M 3/02).

The disadvantages of this stand are:

- the presence of a large number of auxiliary equipment for carrying out hydraulic tests (high pressure pump, liquid tank, two carriages: one has a complex unit for sealing the end of the pipes, and the other has a plug, a hydraulic lock, centering clamps, etc.)

- the occurrence of large longitudinal loads in the cavity of the pipe, location over a large area,

- chain drive of a movable trolley,

- large metal consumption.

Also known is a device for hydraulic testing of tubing, consisting of a fixed frame with a support and supports, loading and unloading mechanisms, sealing and moving longitudinally stationary sealing units with fixing and crimping mechanisms with test fluid (patent for invention No. 2192627, IPC G01M 3 / 08).

This device contains a lot of mechanisms and assemblies for conducting a full test cycle, technological pairs of coaxial movable and stationary sealing assemblies, a high pressure pump, a fluid container, and the design of a movable sealing assembly (plug) reduces the reliability of this device. The ends of the pipes are sealed by screwing on the crimping heads and plugs. The stand is very metal-intensive.

A known installation for hydraulic testing of pipes with threaded ends and a crimping plug for the nipple end of the pipe (patent for invention No. 2360222, IPC G01M 3/08). The specified installation consists of a drive roller table for the longitudinal movement of the test pipe with a sleeve, stationary in the longitudinal direction of the crimping head, connected to the injection fluid supply system and equipped with a fixing unit in it of the sleeve end of the pipe. Opposite the crimping head on the other side of the roller conveyor, a second mounting unit of the crimping plug is installed on the rack at the nipple end of the pipe. The plug includes a housing in the form of a plug nut with a thread corresponding to the nipple thread and holes for communication with the pipe cavity. An elastic cuff is placed in the threaded part of the plug body in the form of a diametrically expanding cup under external influence with a massive base and inner shoulders. A movable hollow rod with holes for communicating the cavity of the pipe under test with the cavity of the cuff is installed in the housing.

The disadvantages of this device are:

- the availability of auxiliary equipment for conducting hydraulic tests (high pressure pump, fluid containers), the occurrence of large longitudinal loads in the pipe cavity;

- high fluid pressure during hydraulic tests, which requires additional safety measures for staff;

- large installation dimensions;

- significant complexity;

- the need to install additional equipment;

- jamming of pipes from two sides;

- long time for the hydraulic test cycle;

- pollution adjacent to the installation area of the working fluid;

- increased noise from the hydraulic pump,

- sealing of the nipple part of the pipe is carried out by screwing the plug nut.

Closest to the technical nature of the utility model is a stand for testing threaded pipe joints for gas tightness STG-1000 (http://vniitneft.ru/stend_isp.htm). The specified stand is designed to determine the tightness limits of threaded joints of various designs of casing and tubing when exposed to internal gas pressure, as well as to comparatively assess the ability of various materials (lubricants, sealants, etc.) to seal threaded joints of one or another design. Thus, this stand is intended exclusively for research work. This stand is a container with water, where the test samples of threaded connections with threaded technological plugs at the ends of no more than 1000 mm are placed. One threaded plug has a fitting for supplying gas under pressure from the plunger pump into the test cavity of the threaded connection. The container is closed by a sealed lid. The disadvantages of this stand, taken by us as a prototype, are:

- the impossibility of testing natural tubing;

- the presence of containers with liquid;

- jamming of samples of threaded joints, on both sides with technological threaded plugs;

- significant complexity and time of testing;

- the use of additional equipment (heating elements for heating the liquid in the test tank);

- the possibility of liquid contamination from the test capacity of the workshop;

- the possibility of use only in laboratory conditions, not the possibility of use in serial production on production lines.

The purpose of the utility model is to create a small-sized test bench easy to maintain and manage, reducing the number of components and mechanisms, reducing the testing time of threaded tubing connections and natural casing pipes.

This goal is achieved by the fact that air is supplied under pressure only into the space of a threaded tubing connection of a natural size without the use of technological threaded plugs.

The technical result achieved by the implementation of the claimed utility model is as follows. On a rigid frame there are: a pneumatic cylinder with a stem, electro-pneumatic valves with a control unit and a movable crimping head with a sealing element - a rubber ring that moves along the guides of the bed. The rod of the pneumatic cylinder is connected with a movable rod, which, due to the support of the spring and the spring itself, moves the crimping head with a sealing element located on the end of the crimping head along the stand along the guides of the stand until it contacts the end of the coupling screwed onto the tubing and seals the threaded connection on the side of the coupling end. The fixed rod inserted into the movable rod has a rubber sleeve at its end - a packer for sealing the inner surface of the tubing after a threaded connection to the coupling. In the crimping head there is an annular groove at the end with a diameter smaller than the inner diameter of the tubing sleeve for communication with the internal cavity of the sleeve and two holes perpendicular to the axis of the crimping head and communicating with the ring groove, one for supplying air to the test cavity of the threaded connection, and the second for installing a control gauge pressure of the forced air. If the pressure on the pressure gauge on the crimping head does not change, then the density of the threaded connection is provided. If the pressure drops, then additional measures must be taken to seal the threaded tubing connection.

The utility model "Stand for pneumatic testing of threaded pipe joints" is illustrated by drawings.

In FIG. 1 shows a General view of a pneumatic stand with additional equipment, containing a frame 1 on which a pneumatic cylinder 2 is fixed with a rod 3 connected through an adapter and rods passing through the housing 4 of the movable pressure head with a sealing rubber sleeve (acting as a packer, not shown in the drawing) The tubing 5, on which the sleeve 6 is screwed on. The control panel 7, the block of electro-pneumatic valves 8 are also fixed on the bed 1. The tubes 9 and 10 serve for supplying and removing air from the cavities of the pneumatic cylinder 2. The tube 11 is intended started to supply air to the threaded tubing connection. The pressure gauge 12 serves to control the tightness of the threaded tubing connection. The spring 13 helps to return the movable rod to its original position. The emphasis 14 (the fixing unit of the coupling 6 with the pipe 5) rigidly mounted on the frame 1 holds the coupling 6 from longitudinal movement during pneumatic testing. The stop 14 (fixation unit) is a metal bar milled from above along the longitudinal axis with a radius smaller than the radius of the pipe 5.

In FIG. 2 is a sectional view of a stand illustrating assembly. The assembly of the stand is as follows. An adapter 15 is screwed into the rod 3 of the pneumatic cylinder 2 (Fig. 2). A hollow movable rod 16 is installed in the housing 20 (Fig. 2) of the pressure head 4 (Fig. 1), in which two o-rings 21 and an o-ring 22 with a flange 23 are installed . The fixed rod 17 is inserted into the movable rod 16 with the through groove A. The pin 18 is installed in the groove A through the through hole in the housing 20, the sleeve 19 and the fixed rod 17. A spring 13 is installed on the rod 16, the spring support 24 with the adjusting nuts 25. Movable the rod 16 through the adapter 15 is connected to the rod 3 of the pneumatic cylinder 2. On the opposite side, screw the compression sleeve 26 into the rod 17. A rubber sleeve (packer) 27, a thrust washer 28 are mounted on the rod 17 and fixed with a nut 29 with a spring washer 30.

The work of the stand is carried out in the following sequence. On command from the control panel 7 (Fig. 1) to the control unit of the electro-pneumatic valves 8, air from the compressor or compressed air storage tank (not shown in the drawings), through the air pipe 9 is supplied to the pneumatic cylinder 2, while the rod 3, through the spring support 24 and the spring 13 moves the clamping head 4 (Fig. 1) with a sealing element 22 mounted on the housing 20 (Fig. 2), to the end of the coupling 6 (Fig. 2), the rubber sleeve 27 enters the inner cavity of the pipe 5 (Fig. 1) ) The sealing ring 22, held by the flange 23, is pressed against the end of the sleeve 6 (Fig. 2) and seals the space B (the space between the end of the rubber sleeve 27, the inner surface of the threaded connection of the pipe-sleeve, the end of the housing 20 due to the sealing ring 22, while the movement of the housing 20 and the fixed rod 17 is stopped. Further movement of the rod 3 causes the spring 13 to be completely compressed and the movable rod 16 with the pressure sleeve 26 relative to the fixed rod 17 to move at a distance equal to the length of the groove A, which leads to compression in the axial direction of the sleeve of the rubber (packer) 27 and the sealing of the space B (Fig. 2) along the inner cylindrical surface of the pipe 5 due to the rubber sleeve 27 and the sealing ring 22. Then, air under pressure is supplied to the housing 20 through the duct 11 (Fig. 1) the threaded connection B enters the channel G and then into the cavity B. The pressure is monitored by a pressure gauge 12 connected to the housing 20 through the threaded hole D connected to the channel D. The threaded connection is held for 10 seconds. If the pressure does not drop, then the threaded connection is tight, otherwise it must be repaired. Thus, the sealing of space B (Fig. 2) for testing is performed in one complete movement (extension) of the rod of the pneumatic cylinder 2. The mechanisms return to their original position in the reverse order: air through the control unit of the electric pneumatic valves 8 by a signal from the control panel 7, through the tube 10 (Fig. 1) enters the pneumatic cylinder 2, which retracts the rod 3, and with it the pressure head 4. The spring 13 is in a compressed state and its compression force acts on the housing 20 on the one hand and on the spring support 24 on the other and in my ent switching air supply direction in the air cylinder (pressing outlet head 4) expands and thereby helps rod of the air cylinder 3 to move the movable rod 16 relative to the stationary rod 17 through the housing 20 and the decompression of the rubber sleeve 27 in the axial direction, which facilitates its withdrawal from the threaded connection. Further movement of the rod 3 displays the clamping head together with the rubber sleeve 27 from the threaded connection and the stand is ready for pneumatic testing of the next threaded connection.

The compression ratio of the rubber sleeve 27 sealing the inner cylindrical surface of the pipe can be adjusted by the length of the groove A of the movable rod 17.

Feasibility or other efficiency:

1. High speed testing of threaded pipe joints in full size.

2. Environmentally friendly workplace.

3. The small size of the stand allows you to enter it in the area of the workshops.

4. Safety of the test

Claims (3)

1. A stand for pneumatic testing of a threaded pipe connection, including a bed, a crimping head, connected with a working medium supply system, characterized in that the crimping head is longitudinally movable, the working medium is air, and air is supplied only to the space limited by the end rubber sleeve installed inside the pipe threaded joint, the inner surface of the pipe threaded joint and the end face of the crimping head. 2. The stand according to claim 1, characterized in that the sealing of the threaded connection of the pipe is made in one movement of the rod of the pneumatic cylinder connected to a movable rod moving relative to the fixed rod in order to compress the rubber sleeve axially and seal the space. 3. The stand according to claim 1, characterized in that the compression ratio of the rubber sleeve, which seals the inner cylindrical surface of the pipe, can be adjusted by the length of the groove of the movable rod.

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