CN204604217U - A kind of stopping transportation pressure changes the device of high compression diameter ball valve - Google Patents

Abstract

A device for replacing a high-compression-diameter ball valve with pressure without stopping transmission, including a plugging head (1), an operating rod (8), a high-pressure sealing chamber (4), a split beam (7), a connecting screw (11), Ring clamp (2) and so on. The high-pressure sealed chamber (4) is connected to the ball valve (3) through the flange, one end of the connecting screw (11) is tightly connected to the pipeline (12) in front of the valve through the ring clamp (2), and the other end is connected to the split beam (7) Connected with each other, push the split beam (7), the operating rod (8) and the plugging head (1) to move together by twisting the nut (6) on the connecting screw rod. There are two split beams (7), and the other one is mainly placed between the valve and the pipeline flange after the valve is disassembled to play the role of secondary fixing the operating rod (8). The device of the utility model can realize the replacement of the high-compression-diameter ball valve safely and quickly without interruption and with pressure.

Description

A device for replacing high-compression-diameter ball valves under pressure without interruption

technical field

The device of the utility model belongs to the technical field of valve maintenance and emergency repair of oil and gas long-distance pipelines, and mainly provides a device required for replacing high-compression-diameter ball valves on-line with pressure without continuous transmission.

Background technique

Oil and gas long-distance pipelines often use various types of high-compression ball valves in bypass processes and branch pipes. During long-term operation, these valves often have valve body leakage, valve internal leakage, trachoma, flange leakage, and failure to maintain grease, etc. A series of potential safety hazards. In addition to taking temporary measures to temporarily alleviate these potential safety hazards on site, in order to completely solve the potential safety hazards at such valves, new valves need to be replaced. Since these valves are generally directly connected to the trunk line of long-distance oil and gas transmission, the pressure is high, and they are flammable and explosive media. Not only will it seriously affect the normal operation of the pipeline, but it will inevitably cause a lot of waste of resources, especially for high-pressure natural gas pipelines. Such an operation requires at least hundreds of thousands of cubic meters of natural gas to be vented. Although there is also a pressure opening and plugging technology at present, which can realize the replacement of valves under pressure without continuous transmission, but for this type of bypass valve, there are often problems with high pressure, thin pipe wall, valve diameter reduction, narrow working space, and direct failure. The length of the pipe section is small, and there is no opening and sealing position, etc., so it is impossible to realize the opening and sealing under pressure. However, this type of valve also has a characteristic, that is, one end is always under pressure when it is connected to the oil and gas main line, and the other end can generally be released to the air. According to this characteristic, this device for axially sealing and replacing the valve from one end of the valve has been developed.

Contents of the invention

The device of the utility model can replace the bypass connected to the main line and the ball valve on the branch pipe online under pressure without stopping the transmission, venting the main line, or welding the fire. less, easy installation, simple operation, high efficiency, short operating cycle, etc., and will not affect the normal operation of the main line, and more importantly, the device adopts the method of indirectly fixing the plugging head to solve the problem of small inner diameter of the valve and shrinking diameter. The resulting plugging head cannot be firmly blocked inside the pipeline. The new type of sealing structure specially developed for replacing the reduced-diameter ball valve can be thinned under the action of extrusion, so as to smoothly pass through the reduced-diameter valve with a smaller inner diameter, and can be squeezed and expanded to become thicker to seal the pipe with a thicker inner diameter. It solves the two relatively contradictory problems of how the plugging structure can smoothly pass through the reduced-diameter valve with a thinner inner diameter, and how to block the high pressure inside the pipeline with a thicker inner diameter.

The whole device mainly includes a plugging head (1), an operating rod (8), a high-pressure sealed chamber (4), a split beam (7), a connecting screw (11), an annular clamp (2), etc. The high-pressure sealed chamber is connected to the reduced-diameter ball valve (3) to be replaced through a high-pressure flange, and one end of the connecting screw (11) is always tightly connected to the pipeline (12) in front of the valve to be replaced through the lug on the ring clamp (2). Fixed connection.

The plugging head (1) is a new type of plugging structure specially developed for replacing the reduced-diameter ball valve. The plugging principle is that under the push of the operating rod (8), the plugging head (1) is moved to the front of the valve that needs to be replaced. Then turn the operating lever (8) to squeeze and expand the plugging head to seal off the pressure of the pipeline. The plugging head can become thinner under the action of extrusion, so that it can smoothly pass through the reduced-diameter valve with a smaller inner diameter. , and can be extruded and expanded to become thicker to block the internal pressure of the pipe with a thicker inner diameter.

The shape of the operating rod (8) is a gradually tapering step shape, and a section of the lower end is hollow, and is connected with the plugging head (1) through an inner thread, the middle part passes through the high-pressure sealing chamber (4), and the upper end is connected to the sealing head (1). The split beam (7) is connected by a thrust bearing. There is a section of outer thread on the upper end, which can be installed with a nut. A section of the top end has a cross-sectional shape of a regular hexagon, which is convenient for tools such as wrenches to block the rotating operating rod.

The high-pressure sealing chamber (4) has two upper and lower chambers, the lower chamber is used to accommodate the plugging head (1), the upper chamber is used to install the high-pressure mechanical seal assembly (9), and the uppermost end is provided with a sealing gland (5) , a grease nozzle (13) for sealing grease is provided on the upper cavity, and a vent port (10) with a valve is provided on the lower cavity. The high-pressure mechanical seal assembly (9) consists of two high-pressure Composed of an oil seal and a spring, the sealing performance is enhanced by injected sealant.

There are two split beams (7), each of which is provided with three large holes, the middle hole passes through the operating rod (8), and the two holes on both sides pass through the connecting screw rod (11). The three holes all adopt clearance fit, and the crossbeam There are a pair of small holes for assembly on the side. The two split beams are cut in the middle and divided into two halves. When in use, they are threaded with bolts and assembled together. The middle round hole of the other split beam is matched with the diameter of the middle part of the operating rod (8). ) for safety protection.

There are two connecting screws (11), one end of which is tightly connected to the pipeline (12) in front of the valve to be replaced through the ear wing on the ring clamp (2), and the other end is connected to the split beam ( 7) connected with each other, a thrust bearing is set between the nut and the split beam (7), and the split beam (7) is pushed to move by twisting the nut, thereby driving the operating rod (8) and the plugging head (1) Move up and down.

The ring clamp (2) is set according to the outer diameter of the pipe in front of the valve, and is divided into two half rings. There is a connecting ear with radial bolt holes on both sides of each half ring. When used, the two halves are encircled Tighten and fix the pipeline with bolts. In addition, there is an ear wing with an axial round hole in the middle of each half ring. The connecting screw (11) passes through the axial round hole and connects with the nuts at both ends. Ear fins are securely attached.

The utility model device has the following characteristics:

①The devices all adopt mechanical structure, which has high reliability and low safety risk.

②With few sealing points, the risk of medium leakage during operation is small.

③The whole device is fixed in front of the valve to be replaced, and under the obstruction of the pipeline flange, the operation process is relatively safe.

④The plugging head is always supported and fixed alternately by two split beams, which can ensure that the plugging head will not slip out of the pipeline.

⑤Using the device to replace the valve under pressure does not need to stop the transmission and vent a large amount of oil and gas resources, and the economic and social benefits are considerable.

⑥ The structure of the device is small and compact, which is very suitable for small diameter and narrow space on the job site.

⑦The axial sealing technology is adopted to avoid the safety risk of hot-fire welding with pressure opening.

⑧The method of fixing the plugging head on the outside solves the problem that the plugging head cannot be firmly blocked inside due to the shrinkage of the valve.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the device.

Fig. 2 is a structural schematic diagram of a high-pressure sealed chamber.

Fig. 3 is a structural schematic diagram of a split beam.

Fig. 4 is a schematic structural view of the ring clamp.

Fig. 5 is a schematic structural view of the operating rod.

The legend shows that in the figure: 1. Plugging head, 2. Ring clamp, 3. Ball valve to be replaced, 4. High-pressure sealing chamber, 5. Sealing gland, 6. Nut, 7. Split beam, 8. Operating rod, 9. High-pressure mechanical seal assembly, 10. Vent port, 11. Connecting screw, 12. Pipeline, 13. Grease nozzle.

Detailed ways

After the device was designed and manufactured according to the size of the DN50 reduced-diameter ball valve, a test platform was set up to simulate the actual situation on the site. Pressure test, etc., and finally achieved the successful replacement of the valve under pressure of 8.2MPa. Judging from the test results, the operation process is simple, safe and reliable, and there is no need to stop the transmission, vent, and fire, and the operation cycle can be completed within one hour. Among them, under the test conditions, the plugging pressure difference of the device can reach more than 10MPa, and when the plugging pressure difference is 8MPa, after 24 hours of steady pressure observation, the plugging effect is good, without any leakage and obvious displacement deformation. The specific implementation mode of device is as follows:

First, remove the flange and pipe on the side of the valve to be replaced that is not connected to the main line under the premise of venting and pressure relief, and install the assembled device in place as shown in Figure 1. The high-pressure sealing chamber (4) and the valve flange To connect, the ring clamp (2) is firmly stuck on the pipeline (12) in front of the valve to be replaced, and the plugging head (1) is in the lower cavity of the high-pressure sealing chamber.

Close the valve on the vent (10), slowly open the old valve to be replaced until the valve is fully open, use a ratchet wrench to twist the nut (6) on the connecting screw (11), and push the split beam (7 ) to move forward, thereby driving the operating rod (8) and the plugging head (1) to also move forward. When the flange surface on the pipeline is flush, stop twisting the nut (6) on the connecting screw rod. Generally, it can be judged whether the two are flush by measuring the moving distance of the operating rod and the actual size of the valve on site.

Turn the operating rod (8) with a wrench to squeeze and expand the plugging head (1) to seal off the pipeline pressure. After the pressure is blocked, open the control valve on the vent port to vent and release the pressure. Observe for 5 minutes. After confirming that there is no leakage, disassemble the flange connection between the valve to be replaced and the pipeline, and put the flange pad Remove the piece and the valve from the pipe flange together, and at the same time install another split beam in this gap to ensure that the split beam clamps the boss at the lower end of the operating rod (8), and connect the screw rod (11 ) to fasten the split beam, thereby ensuring that the operating rod and the plugging head are supported and fixed firmly by the split beam.

Remove the split beam (7) at the upper end of the device, pull out the old flange gasket, old valve, and high-pressure sealing chamber (4) from the operating rod, and then sequentially remove the new gasket, new valve, and high-pressure sealing chamber. Storehouse is passed on the operating bar again, and split type crossbeam (7) is installed again, supports and fixes operating bar.

Remove the split beam at the lower end of the device, fasten the two ends of the new valve to connect the pipe flange and the flange of the high-pressure sealed chamber, close the valve on the vent (10), and turn the operating rod (8) in the opposite direction with a wrench , so that the plugging head is no longer squeezed and expanded, and after the plugging of the pipeline is completely released, the nut (6) on the connecting screw rod is twisted in the opposite direction with a ratchet wrench. Under the action of the internal pressure of the pipeline, the plugging head, The operating rod and the split beam will move backward together, and when the plugging head completely enters the lower cavity of the high-pressure sealing chamber, close the replaced new ball valve.

Open the control valve on the vent (10) for venting and pressure relief, remove the entire device, and reinstall the flange and the pipeline on the side where the new valve is not connected to the main line to restore the original state.

Claims (6)

1. the device of a stopping transportation pressure replacing high compression diameter ball valve, comprise block head (1), action bars (8), high pressure sealing storehouse (4), split-type crossbeam (7), connecting screw rod (11), ring-shaped clip (2), the high pressure sealing storehouse of described device is coupled together with needing the reducing ball valve (3) changed by high pressure flange.

2. change the device of high compression diameter ball valve according to stopping transportation pressure described in claim 1, it is characterized in that:

The shape of described action bars (8) is the stepped ramp type progressively attenuated, lower end has one section to be hollow, and linked together by internal thread and block head (1), mid portion is through high pressure sealing storehouse (4), upper end is connected by thrust bearing with split-type crossbeam (7), and there is one section of outer silk upper part, can install nut, have one section of cross sectional shape to be regular hexagon topmost, the instruments such as convenient wrench block rotating operation bar.

3. change the device of high compression diameter ball valve according to stopping transportation pressure described in claim 1, it is characterized in that:

Described high pressure sealing storehouse (4) has upper and lower two cavitys, lower cavity is used for holding block head (1), upper chamber is used for installation high-voltage mechanical sealing assembly (9), be provided with sealing gland (5) topmost, upper chamber is provided with the greasing mouth (13) that is used for noting stop-leak compound, lower cavity is provided with the drain (10) of a band valve, high-pressure mechanical seal assembly (9) is made up of two High-pressure oil sealings and a spring, relies on the stop-leak compound of injection to strengthen sealing property further.

4. change the device of high compression diameter ball valve according to stopping transportation pressure described in claim 1, it is characterized in that:

Described split-type crossbeam (7) has two, every root is provided with three macropores, interstitial hole dress operation bar (8), connecting screw rod (11) is worn in two holes on both sides, three Kong Jun take matched in clearance, crossbeam side is provided with the aperture being used for for a pair assembling, two split-type crossbeams all cut dimidiation open along centre, wearing with bolt during use is assembled into together again, the middle circular hole of another root split-type crossbeam and the mid portion diameter of action bars (8) supporting, its main application is after valve dismounting, be placed between valve and underwater flange, secondary fixes action bars (8), play safety protection function.

5. change the device of high compression diameter ball valve according to stopping transportation pressure described in claim 1, it is characterized in that:

Described connecting screw rod (11) has two, its one end is fastenedly connected by the earflap on ring-shaped clip (2) and the pipeline (12) before valve to be replaced, the other end is connected with split-type crossbeam (7) by nut (6), thrust bearing is provided with between nut (6) and split-type crossbeam (7), promote split-type crossbeam (7) by twisting nut (6) mobile, thus drive action bars (8) and block head (1) to move up and down.

6. change the device of high compression diameter ball valve according to stopping transportation pressure described in claim 1, it is characterized in that:

Described ring-shaped clip (2) is arranged according to the outer diameter tube before valve, and subdivision is two semi-rings, there is a connection earflap being with radial bolts hole on the both sides of each semi-ring, encircled on pipeline two and half during use, tighten fixing with bolt, in the middle of each semi-ring, be also provided with the earflap of an axial circular hole of band in addition, connecting screw rod (11) through this axial circular hole, and is firmly connected with earflap by two ends nut.