RU2661420C2 - Closing system for pressurized pipelines - Google Patents

Abstract

FIELD: pipes.

SUBSTANCE: invention relates to a closing system for pressurized pipelines, in particular to the closing fitting fittings for the purpose of tie-in without lowering the pressure in the pipeline. Closing system comprises one fitting having a lower end, which is adapted to be connected around the opening of the conduit, and an upper end having an opening adapted to receive a closing plug therein. Plug is integrated with the fitting by means of fixing screws, each of which is adapted to engage with the stop surface of the plug. To interact with the protruding ends of the fixing screws, the stop surface of the plug is chamfered at the same angle as the screws, this allows to correct the deviations of the plug relative to the flange hole, while maintaining the reliability of the plug and flange connection. Guide surface of the plug has a conical shape, allowing, when plugging the plug hole in the fitting, to exclude deviations from the axis of the hole. After the completion of the work on the design of the closing system, a plug on the welding is installed.

EFFECT: invention improves the accuracy of fitting the plug into the fitting and the reliability of the installation process.

1 cl, 5 dwg

Description

The present invention relates to a closing system, in particular to closing shaped fittings with the aim of tapping without reducing the pressure in the fluid pipe, in particular gas. The present invention further relates to a method for installing a closure system used to block pipelines for transporting water, gas or other pressurized fluids. Closing systems are known in the art that are typically used to plug shaped fittings used to block pipelines for transporting water, gas, or other pressurized fluids.

A similar system is known from the patent for invention No. 2484355, F16L 41/04, publ. 06/10/2013

A closure system comprising at least one large fitting having a first end adapted to be connected around a pipe opening and a second end having an opening configured to accommodate at least one closure plug within it, the plug being combined with the fitting by means of at least three radial fastening pins, each of which is adapted to engage with at least one corresponding radial receptacle located on the perimeter bki, the locking pin is provided at least partially an outer thread adapted to grip a corresponding internal thread accommodating slot, and fastening the end protruding from the accommodating sockets for engagement with plug socket, the socket wall are chamfered to create mutual interference with the fixing of the pin end.

The disadvantages of this device are:

- when closing the hole with a stopper with at least three fixing pins, with their fixing ends, they must engage with the socket of the stopper. In this case, the entire cylindrical surface of the plug socket works, although the pressure of the transported medium affects only their lower part. As a result, the upper part of the lightly loaded inner surface of the plug socket is in danger of skewing due to clogging with dirt and stopping the further passage of the pins; when screwing at least three fastening pins into the plug socket, a greater degree of installation dimension accuracy is necessary, since with small distortions from dirt the upper edges of the mounting pins the ends of the pins may not align with the top edge of the inner surface of the plug socket. In this case, the cause can be eliminated only after removing and inspecting the surface condition of the socket, plug and pins;

- if dirt or other reasons get under the o-ring, it becomes necessary to ensure the tightness of the seal of the plug and fitting connection by screwing in at least one radial fastening pin, however, this is impossible, since the further movement of the fastening pins is limited by the back wall of the socket;

- in case of insufficiently accurate alignment of the shut-off valves or the device for drilling the pipe installed on the end of the fitting, the plug closing the hole may not sit in the seat;

- upon completion of work, protective covers are mounted on the threads in the empty seats of the accommodating sockets, which is not reliable enough to ensure safety during further operation of the gas pipeline as a result of failure of the gaskets or corrosion over time, gas leakage from the threaded joints of the pins and nests. GOST R 55472-2013 pp 8.3.2., 8.3.3 prohibits the use of such compounds in an underground gas pipeline.

To address these shortcomings, the following is provided:

- to eliminate the risk of skew when clogged with dirt and stop missing pins, the role of the plug socket in the proposed plug design is performed by a radial thrust surface. At the same time, each of the fixing screws has the ability to capture this radial thrust surface;

- the effect of each fastening screw on the radial thrust surface ensures a tight connection between the plug and fitting through the sealing ring as a whole, if necessary, it is possible to pull the bolts with different forces, since the conical end of the fastening screw is limited only by the radial thrust surface;

- to ensure a guaranteed fit of the plug into the fitting seat, the plug design of the closure system provided provides a guide surface that prevents jamming of the plug when passing through the fitting shoulder and corrects the spatial position of the plug with this surface;

- to prevent leaks through the closure system of the medium transported by the pipeline during operation, it is proposed to install a single plug on the fitting of the closure system by welding instead of at least three protective covers equipped with at least one threaded part configured to capture the internal thread of the accommodating nests, the heads of which are provided with at least one socket, in particular a hexagonal recess, for accommodating a twisting and unscrewing tool.

Therefore, the object of the present invention solves the aforementioned problems of the prior art by developing a closure system for a fitting in which a plug can be combined with a corresponding fitting without using a socket on the plug, which makes the plug closing operation more reliable and simple. The above and other objectives and advantages of the invention, as will be understood from the following description, are achieved by a closing system, as described in the claims.

The essence of the work of the present invention is shown through the drawings of the phased production of works on which:

FIG. 1 is a cross-sectional side view of a closure system, the interaction of fitting elements, plugs, fastening bolts and other elements and parts in creating the necessary tightness of the plug and fitting connection according to the present invention.

FIG. 2 is a sectional side view of the operation of a locking system in a pipeline drilling operation according to the present invention.

FIG. 3 is a sectional side view of the operation of the locking system when installing the locking plug after completion of drilling of a pipeline or blocking of pipelines for transporting water, gas or other pressurized fluids according to the present invention.

FIG. 4 is a sectional side view of the operation of the locking system when checking the tightness of the joints made after installing the locking plug according to the present invention.

FIG. 5 is a sectional side view of the state of the locking system after completion of all work according to the present invention.

List of parts and elements with digital designation

1 Inventory bolt

2 O-ring

3 Holding element

4 Fitting

5 Cork

6 O-ring

7 Fixing screw

7a External thread of the fixing screw 7

7b Tapered mounting end of the fixing screw 7

7c Mounting screw socket 7 for inserting a tool

8 cap

9 Crimping unit

10 safety bolt

11 Bottom end fitting

12 Upper end

13 Hole of the upper end

14 Radial thrust surface

15 Guide hole

16 shoulder shoulder

17 Guide conical surface

18 Mill

IMPLEMENTATION OF A CLOSING SYSTEM FOR PIPELINES UNDER PRESSURE

With reference to the drawings, it can be seen that the closure system according to the present invention comprises one fitting 4, the shape of which is cylindrical with an axis of symmetry indicated by a straight line S-S in FIG. 1, having a bottom end 11 configured to be welded around a hole in the pipeline, and an upper end 12, equipped with an opening 13, the shape of which is round, configured to place a closing plug 5 inside it, in alignment with the axis of symmetry SS, moreover, the plug 5 is combined with the fitting 4 and, in particular, inside the hole 13 of the upper end 12 of the fitting 4 by means of eight radial fixing screws 7, thus having an axis of symmetry PP, perpendicular to the axis of symmetry SS f of iting 4 and plug 5, each of which is capable of engaging with the radial abutment surface 14 located on the perimeter of plug 5, passing through one corresponding guide hole 15 of the radial fitting 4, also having an axis of symmetry coinciding with the axis of symmetry of the PP mounting screws 7 , and passing through the upper part of the fitting 4. It is obvious that if the fitting 4 should be combined with the curved surface of the pipeline, then its lower end 11 will be essentially shaped. In order to install the plug 5 in the hole 13 and in the seat of the fitting 4 completely, in particular, to align the guide holes 15 of the fitting 4 along the perimeter of the radial thrust surface 14 of the plug 5 without deviating from the axis of the PP and to ensure that the fixing screws are freely screwed in 7, the fitting 4 is equipped inside the shoulder of the protrusion 16 in the fitting 4 for stopping the plug 5 itself through the o-ring 6. The plug 5 is provided with a guide surface 17 which has a conical shape. The task of the guide surface 17 is to prevent the plug 5 from jamming when the shoulder 16 passes through the fitting 4. The plug 5 with the surface 17 starts to lower from the shoulder 16 with a gap of 3 mm in one direction, at the end of the movement and the stop in the shoulder 16, the gap is 0.5 mm. With inaccurate installation of the device for installing the plug 5, the correct fit is corrected by this surface.

In order to provide easier alignment between the guide hole 15 and the fixing screw 7 and engagement with the radial thrust surface 14 of the plug 5, the latter is made as one perimeter common edge in the plug 5: thus, the connection between the fixing screw 7 through the guide hole 15 and a radial thrust surface 14 can occur, whatever the angular orientation of the plug 5 around the axis of symmetry SS, as soon as the plug 5 rests on the shoulder 16. In this case, each of the fixing screws 7 is made with possibly grip by the radial thrust surface 14. The fastening screw 7 is equipped with an external thread 7a and a conical fastening end 7b protruding from the guide hole 15 for engagement with the radial thrust surface 14 of the plug 5. The end face of each fastening screw 7 corresponding to the guide hole 15 communicating with the outer side fitting 4, is equipped with a socket 7c for inserting a tool intended for screwing and unscrewing the fixing screw 7, necessary for combining the plug 5 with fitting 4, or, conversely, in the case after uyuschego removal tube 5. The upper end 12 of the fitting 4 is equipped with means for connection to the tripping armature, through which the device can be set plugging a pipeline or drilling pipe device, such connecting means comprises a connecting flange. Therefore, the dimensions of the upper end face 12 of fitting 4 are made in accordance with GOST 12820-80 “Flat welded steel flanges. Design and dimensions ”for the corresponding diameter of the stop valves. The fitting 4 is equipped with a holding element 3, through which it interacts with a pipe plugging device or a pipe drilling device.

Below in this document, steps are described for installing the plug 5 during an operation of blocking a pipe or a pressurized pipe drilling device.

At the first stage, the shaped fitting is welded to the pipeline, then the fixing screws 7 are removed from the guide holes 15, the inventory bolts 1 are screwed into their guide holes 15. As a result of the shoulders pressing the inventory bolts 1, the sealing rings 2 to the troughs of the guide holes 15 by means of a tool, the necessary sealing of the connections of the guide holes 15 and inventory bolts 1, which can withstand the pressure of the medium transported through the pipeline during drilling of the hole in the existing pipe the pipeline transporting the medium contained therein under operating pressure or when lowering the plug 5 to the opening of the fitting seat 4.

At the upper end 12 of the fitting 4, a temporary shut-off valve is installed, through which it is possible to drill a pipeline under pressure by means of a suitable device for drilling pipes.

In a second step, a fluid blocking system is assembled at the site of the pipe drilling apparatus, and then it operates on the pipeline. The third stage consists of removing the blocking system and preparing for the installation of plug 5.

The fourth step is to install the plug 5 in the hole 13 of the fitting 4 and to obtain an impermeable plugging of the shaped fitting 4 with the plug 5. By means of a suitable device for drilling pipes with a mechanical or hydraulic drive, the plug 5 is inserted through a temporary stop valve to the hole of the fitting seat 4, where at when the drive of the device is affected by mutual compression of the sealing ring 6 and the shoulder of the protrusion 16 of the fitting 4, the pipeline is plugged and the connection of the plug 5 with the fitting is completely sealed 4. Now, through the drain valve present in the device for drilling pipes, the residual pressure of the medium is released, after which the inventory bolts 1 are unscrewed and the fixing screws 7 are screwed into the guide holes 15 instead.

After that, the compression force created by the device for drilling pipes is removed. Through the drain valve of this device, check the tightness of the connection of the plug 5 and fitting 4, sealed with a sealing ring 6 with the fastening screws 7. In case of incomplete sealing of this connection with a tool, fasten the fastening screws 7 in the guide holes 15. The design of the fastening screws 7 and the contact surface 14 plugs 5 eliminates the distortion of the connection of the plug 5 and fitting 4.

When the tightening of the fixing screws 7 is successfully completed and through the drain valve of the device for drilling pipes for pressure leakage of the transported medium from the existing pipeline does not occur, this device, as well as the temporary disconnecting fittings from the upper end 12 of the fitting 4 are removed. In place of the removed valves on the upper end 12 of the fitting 4, a permanent plug 8 is installed in a special recess 8. The plug 8 protects against corrosion and mechanical damage, as well as from unexpected destruction of the sealing elements and depressurization of the installed closing system. Since the plug 8 is a permanent element of the pipeline and is designed for the entire period of its further existence, the plug 8 is welded by welding. After that, quality control of the performed connection is performed. For this purpose, a crimping unit 9 is screwed into a specially provided hole in the installed plug 8, air is pumped under a certain pressure, and after a specified time, the quality of the connection made is determined by a pressure gauge. After checking the quality of the joints, the crimping unit 9 is removed, the safety bolt 10 is screwed in its place and welded.

Claims (1)

A closure system comprising one fitting having a bottom end configured to attach around a pipe opening, and an upper end having a hole configured to receive a closure plug inside, the plug being integrated with the fitting by means of radial fastening screws, each of which is made with the possibility of adhesion to the stop surface of the tube, also the mounting screws are provided with an external thread, made with the possibility of capturing the corresponding internal thread of the guides holes, and a fastening conical end protruding from the guide holes for engaging with the stop surface of the stopper, the stop surface of the stopper being beveled at the same angle as the screws, characterized in that the radial stop surface plays the role of the stopper socket, with each fastening the screw on the radial thrust surface provides a tight connection of the plug and fitting through the o-ring as a whole, if necessary, they can be used to attract individual sections of the plug with different by force, the guiding surface ensures a guaranteed fit of the plug into the fitting seat, while avoiding jamming of the plug when passing through the fitting shoulder and correcting the spatial position of the plug with this surface, the fitting is equipped with a single plug protecting the closing system.

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