RU2750363C1 - Stand for hydraulic pipe tests - Google Patents

Abstract

FIELD: testing equipment.

SUBSTANCE: invention relates to testing equipment, namely to installations for hydraulic testing of pipeline elements for strength, tightness and durability. The stand for hydraulic testing of pipes contains a frame, a process pipe equipped with sealing plugs at the ends of the process pipe, adjustable supports ensuring the alignment of the test and process pipes, as well as a drive system and a system for creating a test pressure of the liquid in the annular cavity. The sealing plugs are equipped with clamping mechanisms, made with the possibility of pressing the flanges of the plugs to the welded ends of the tested pipe, and the process pipe is equipped with mechanized stops located inside the pipe at both its ends and excluding the displacement of the clamping mechanism and these pipes in the axial direction during testing.

EFFECT: increasing the reliability of the results of hydraulic tests of pipes by ensuring the necessary tightness of the stand elements when testing pipes with corrosive, mechanical damage to the outer surface and "cutting obliquity".

4 cl, 6 dwg

Description

The invention relates to testing equipment, namely to installations for hydraulic testing of pipeline elements for strength, tightness and durability.

A device for hydraulic testing of pipes is known (AS USSR No. 1370470, G01M 3/08, publ. 20.01.1988), containing a hingedly mounted on supports with the ability to rotate around the longitudinal axis of a rectangular frame with longitudinal guides on which a cart with cradle is located connected by longitudinal beams, two supports, movable and fixed plugs and a movable plug drive, made in the form of screw pairs, the nut of which is rigidly fixed on a movable plug connected to the frame with the possibility of longitudinal movement relative to it in the direction of the fixed plug, the latter is installed on one of the supports , and the drive of the movable plug is on the other support, and the hydraulic system is connected to one of the plugs.

The disadvantage of the known device is the unreliability of sealing the tested pipes, the laboriousness of the tests, high energy consumption and a long time of filling the test pipes with a working fluid.

Closest to the claimed stand is a stand for hydraulic testing of shells of revolution in the factory and in the field, including pipes (RU 2247957, G01M 3/08, publ. 03/10/2005), containing as a base frame with fixed and movable plugs installed on it ... The fixed plug is made in the form of a ring for free passage of the mandrel through it. A mandrel is rigidly fixed on the movable plug, which is introduced coaxially into the test pipe to form a cavity into which the liquid is supplied. The sealing of the formed cavity is performed using a hydraulic system by pressing the plugs. The cavity is filled with working fluid and a hydraulic test of the pipe is performed. The cavity is sealed by means of sealing collars on the outer surface of the tested pipe.

However, with the existing ovality at the ends of the pipes of real pipelines, which, in accordance with the specifications of the manufacturing plants, can be no more than 1% (for 01420 mm - 14.2 mm) of the outer diameter, as well as provided that the profile of the outer surface of the pipe deviates from the circumference in the area of the longitudinal weld, which can reach 1.5% of the outer diameter, the known system of sealing along the outer surface of the pipe will be unreliable.

In addition, in accordance with the requirements of the technical specifications for pipes of various manufacturing plants, the deviation from the perpendicularity of the pipe end ("cut angle") can reach 1.6 mm, regardless of the pipe diameter.

Such a sealing system will not work reliably when testing pipes with an "oblique cut" of up to 1.6 mm, as well as pipes that have been in operation, since the outer surface of these pipes, as a rule, has corrosion and mechanical damage. In addition, there is a rapid failure of the seals due to intense abrasive wear.

Therefore, the main disadvantage of the known stand is its unsuitability for hydraulic testing of pipes that have a "cut angle" and were in operation, i.e. having corrosion and mechanical damage to the outer surface, as a result of low sealing of plugs and cuffs along the outer surface of the pipe, which leads to unreliable test results.

The technical task is to create a stand for hydraulic testing of pipes, which provides high reliability of test results for pipes with corrosion, mechanical damage to the outer surface and "oblique cut".

The technical result is an increase in the reliability of the results of hydraulic tests of pipes by ensuring the necessary tightness of the stand elements during testing.

The technical result is achieved by the fact that a stand for hydraulic testing of pipes, containing a frame, a process pipe equipped with sealing plugs at the ends of the process pipe, adjustable supports ensuring the alignment of the test and process pipes, as well as a drive system and a system for creating a test fluid pressure in the annular cavity, According to the invention, the sealing plugs are equipped with clamping mechanisms made with the possibility of pressing the flanges of the plugs to the welded ends of the tested pipe, and the process pipe is equipped with mechanized stops placed inside the pipe at both ends and excluding the displacement of the clamping mechanism and these pipes in the axial direction during testing ...

Reliable sealing of the annular cavity, into which the liquid enters, is ensured properly in the case when the mechanisms that ensure the abutment and clamping of the ends and outer surfaces of the tested pipes against the sealing plugs are located at both ends of the pipes. The power stop is outside the test pipe. The regulation of the pressure created by these mechanisms allows each of the two ends of the pipe under test to be sealed and individually pressed against the plugs, regardless of surface defects. The tightness of the compression is guaranteed if the ends of the test pipe have been pre-welded.

In this case, the mechanized stop is made in the form of a rigidly fixed plate with a crank mechanism, along the circumference of which there are cylinders with fingers moving inside them.

The clamping mechanism can be made in the form of a ring with clamping screws evenly fixed around the circumference, which press the plug flange with a gasket to the prepared end of the tested pipe, sealing the cavity in the annular space.

In the case of insufficient length of the tested pipe, the clamping mechanism can be additionally equipped with an expansion joint consisting of two rings spaced at a distance from each other and rigidly connected to each other by fingers.

When tightening, the clamping screws press on the expansion joint and press it with protruding pins against the flanges of the plug.

The technological pipe is made with wheel supports, on which the technological pipe is quickly rolled inside the tested one, and the drive system is made by cable.

The invention is illustrated by the following figures.

FIG. 1 shows a general view of the inventive stand, FIG. 2 - clamping mechanism.

FIG. 3 shows the possible configurations of the machined ends of the tested pipe (two options).

FIG. 4 illustrates the point of contact between the machined pipe end and the sealing plug flange.

FIG. 5 shows the design of the mechanized stop.

FIG. 5a - fingers extended, FIG. 5b - fingers are pushed in.

FIG. 6 shows the structure of the compensator.

Figures 1-6 show the following structural elements of the proposed stand for hydraulic testing of pipes:

1 - stand frame;

2 - lodgment;

3 - adjustable supports;

4 - technological pipe;

5 - wheel supports of the technological pipe 4;

6 - powered stop;

7 - clamping mechanism;

8 - compensator;

9 - drive system;

10 - system for creating fluid pressure;

11 - test pipe;

12 - finger of the mechanized stop 6;

13 - crank mechanism;

14 - sealed cavity in the annular space;

15 - sealing plug;

16 - gasket of the sealing plug 15;

17 - clamping screw;

18 - plug flange 15;

19 - a ring of the clamping mechanism 7;

20 - compensator ring 8;

21 - a pin with an emphasis of the compensator 8;

23 - cylinder of the clamping mechanism 7;

24 - plate of the crank mechanism 13;

25 - hold-down washer;

26 - bolt;

27 - O-ring.

The technological pipe 4 is equipped with mechanized stops 6 located inside the pipe 4 at both ends (Fig. 1).

The mechanized stop 6 is made in the form of a rigidly fixed plate 24 with a crank mechanism 13, around the circumference of which cylinders 23 with fingers 12 moving inside them are installed (Fig. 5)

The clamping mechanism 7 is made in the form of a ring 19 with clamping screws 17 with nuts (not shown) uniformly fixed around the circumference. For sealing along the outer cylindrical surface of the process pipe 4, a clamping washer 25 is provided in the clamping mechanism 7, which, using bolts 26, clamps the sealing ring 27 (Fig. 2).

Test pipes 11 must have grooved ends for assembly for welding in accordance with the requirements of STO Gazprom 2-2.2-136-2007 "Instruction on welding technologies during the construction and repair of field and main gas pipelines." This requires machining the edges of the ends, as shown in FIG. 3.

If the pipe thickness is less than 15 mm, then the edge configuration should correspond to the variant shown in Fig. 3a, i.e. with an angle of inclination of 30 degrees. If the pipe thickness is 15 mm or more, then the edge configuration is carried out along a broken line (with inclination angles of 35 and 16 degrees), i.e. according to the variant shown in FIG. 3b). In both cases, the sealing will be equally high.

Placement of the tested pipe on the stand and hydraulic tests are carried out as follows.

The test pipe 11 is laid on the lodgments 2 rigidly fixed to the frame 1. Adjustable supports 3 installed on the frame 1 are adjusted to the height so that when the process pipe 4 is laid on them, the axis of the specified pipe 4 coincides with the axis of the test pipe 11, t .e. so that pipes 11 and 4 are coaxial.

Then, with the help of a drive system 9, for example a cable, the process pipe 4 is brought inside the test pipe 11. Thanks to the wheel bearings 5 installed in the process pipe 4, the latter is rolled into the required depth without hindrance.

The fingers 12 of the mechanized stops 6 are brought into the working position by means of the crank mechanism 13, preventing the movement of the clamping mechanism 7, pipes 4 and 11 in the axial direction during testing.

If the length of the test pipe 11 is less than the standard value, on the one hand, an expansion joint 8 is mounted between the clamping mechanism 7 and the test pipe 11 (Fig. 6). It consists of two rings 20 and fingers 21 located around the circumference with protruding stops (not shown). Pins 21 and rings 20 are connected by welding. The compensator 8 is freely put on the process pipe 4, because the inner diameter of the rings 20 is slightly larger than the outer diameter of the process pipe 4.

On the one hand, the clamping screws 17 of the clamping mechanism 7 are pressed against the fingers 21 with stops, and on the other side they abut against the flange 18 of the plug 15 with the gasket 16. When tightening, the clamping screws 17 press on the compensator 8 and press it together with the flange 18 to the process pipe four.

To create a sealed cavity 14 in the annular space, clamping mechanisms 7 and plugs 15 are installed on both sides of the process pipe 4. By twisting the clamping screws 17 alternately, the flange 18 of the plug 15 with the gasket 16 is pressed against the machined end of the test pipe 11. Due to the pretreatment of the ends (Fig. 3, 4) there is no gap between the end of the pipe 11 and the flange 18. The tightness of the cavity in the annular space 14 is ensured.

With the help of the system for creating a test pressure 10, a working fluid is supplied to the cavity 14 of the annular space and the pressure is raised to a predetermined value. After carrying out hydraulic tests, the pressure in the cavity 14 is released, the liquid is drained, then the clamping force is removed from the flange 18 of the plug 15 by loosening the clamping screws 17.

With the help of the crank mechanism 13, the fingers 12 of the mechanized stop 6 are removed inside the process pipe 4, allowing the clamping mechanisms 7 to be dismantled on both sides.

Process pipe 4 using the drive system 9 is removed from the test pipe 11.

Claims (7)

1. A stand for hydraulic testing of pipes, containing a frame, a process pipe equipped with sealing plugs at the ends of the process pipe, adjustable supports ensuring the alignment of the test and process pipes, as well as a drive system and a system for creating a test fluid pressure in the annular cavity, characterized in that the sealing plugs are equipped with clamping mechanisms made with the possibility of pressing the flanges of the plugs to the welded ends of the tested pipe, and the process pipe is equipped with mechanized stops located inside the pipe at both ends and excluding the displacement of the clamping mechanism and these pipes in the axial direction during testing. 2. The stand for hydraulic testing of pipes according to claim 1, characterized in that the powered stop is made in the form of a rigidly fixed plate with a crank mechanism, around the circumference of which cylinders with fingers moving inside them are fixed. 3. Stand for hydraulic testing of pipes according to claim 1, characterized in that the clamping mechanism is made in the form of a ring with clamping screws evenly fixed around the circumference. 4. Stand for hydraulic testing of pipes according to claim 1, characterized in that the clamping mechanism is additionally equipped with a compensator consisting of two rings spaced apart from each other and rigidly connected to each other by fingers. 5. Stand for hydraulic testing of pipes according to claim 1, characterized in that the process pipe is made with wheel bearings, and the drive system is made of cable.

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