CN115163961A - Fast plugging method for reserved interface of long-distance pipeline - Google Patents

Abstract

The invention discloses a quick plugging method for a reserved interface of a long-distance pipeline, and relates to the field of long-distance natural gas pipelines. The method includes the following steps: Step A, preprocessing the reserved interface; The shrinkage tape is laid flat on the reserved interface, and the heat shrinkable tape is wrapped around the end of the tube; then the fixing sheet is overlapped with the heat shrinkable tape along the pipe diameter direction; step C, use heating equipment to uniformly heat the reserved interface; step D, After the heating is completed, wait for the heat shrinkable tape to cool and shrink naturally, and the blocking is completed; in step E, after the blocking is completed, the blocking quality is checked. The invention has the advantages that the reserved interface of the long-distance pipeline can be blocked conveniently and quickly.

Description

Fast plugging method for reserved interface of long-distance pipeline

technical field

The invention relates to the field of long-distance natural gas transmission pipelines, in particular to a method for quick plugging of reserved interfaces of long-distance transmission pipelines.

Background technique

According to the requirements of the specification "GB/T50369-2014", long-distance laying of natural gas long-distance pipelines is strictly prohibited, so it is required to reserve joints at the pipe ends at intervals for welding the pipelines before the ditch. In order to prevent debris, accumulated water, etc. from entering the pipe through the interface, the pipe interface must be blocked in time. The general practice is to weld blind plates to block the ends. For example, the patent document with the publication number of CN204852761U discloses a quick-opening blind plate for temporary blocking of long-distance pipelines, including an open-close door and a fixed door, and the open-close door and the fixed door are composed of Round blind plates are welded to the pipe ends. The main disadvantages of the method of welding blind plates to block the ends include: heavy welding equipment needs to be called before welding, which is inconvenient for construction; the blind plate manufacturing process is complicated; it takes 50 minutes to weld one pipe end, which takes a long time and occupies pipeline engineering. Welding personnel will indirectly affect the welding progress of the main pipeline; flaw detection is required after welding, which increases the cost; the removal of the blind plate is cumbersome and requires acetylene gas cutting; there is a gap at the end of the pipe after gas cutting, which needs to be re-polished during welding, which wastes a lot of manpower and material resources and indirectly affects Welding quality; the pipe end is exposed in a humid environment after welding, and the outer wall is seriously corroded; temporary electricity is involved during welding, the construction process is cumbersome, and the safety threat is great.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is how to plug the reserved interface of the long-distance pipeline conveniently and quickly.

The present invention realizes and solves the above-mentioned technical problem through the following technical means: the quick plugging method of the reserved interface of the long-distance pipeline, comprising the following steps:

Step A, preprocessing the reserved interface;

Step B, using a heat shrinkable tape with a width larger than the diameter of the pipe to be laid on the reserved interface, wrapping the heat shrinkable tape around the pipe end; and then overlapping the fixing sheet with the heat shrinkable tape along the pipe diameter direction;

Step C, using heating equipment to evenly heat the reserved interface;

Step D, after the heating is completed, wait for the heat shrinkable tape to cool and shrink naturally, and the blocking is completed;

In step E, after the blocking is completed, the blocking quality is detected.

The invention uses lightweight heating equipment during construction, which is easy to carry; heat shrinkable tape is a commonly used material for construction and is easy to obtain; construction speed is fast, and it only takes 15 minutes to block one pipe end, saving a lot of time; construction does not need to occupy long-distance pipelines. ensure the continuous development of welding work of the main pipeline; no need to do flaw detection after blocking, which saves the cost of flaw detection; the heat shrinkable tape is easy to remove; Improve welding quality; after plugging, the pipe end is wrapped by heat shrinkable tape, which has good anti-corrosion effect and can be in a humid environment for a long time; compared with the traditional welding blind plate method, the construction process is simple, safe and reliable.

Preferably, step A specifically includes the following steps:

Step a1, use a portable liquefied gas tank gun to perform surface heat treatment on the reserved interface, so that the surface temperature of the reserved interface is preheated to at least 5°C above the dew point;

Step a2, after the heat treatment is completed, rust removal is performed on the surface of the reserved interface; if manual rust removal is used, the rust removal grade reaches St3 level; if sandblasting is used, the rust removal grade reaches Sa21/2 level;

Step a3, according to the product instructions, prepare the primer for anti-corrosion repair and evenly brush it to the reserved interface. The thickness of the primer is greater than or equal to 150um.

Preferably, in step B, the overlapping length of the heat shrinkable tape and the outer wall of the tube end is required to be greater than or equal to 100mm after shrinkage, and the overlap length of the fixing sheet and the heat shrinkable tape is required to be greater than or equal to 80mm after shrinkage.

Preferably, in step C, the heating device adopts a portable liquefied gas tank gun.

Preferably, in step D, the fluidity of the glue is checked by a finger pressure method during the shrinking process of the heat shrinkable tape, and it is qualified if the finger indentation disappears automatically.

Preferably, step E specifically includes the following steps:

Step e1, visually inspect the appearance of the reserved interface;

Step e2, use an electric spark leak detector to perform leak detection on the reserved interface, and the detection voltage is 15kV. If there is a leak, re-block and perform leak detection again until no leak is detected;

Step e3, use peel strength testing equipment to test the peel strength of the reserved interface, the temperature of the pipe body during the test is 15°C to 25°C, the qualified standard is that the peel strength at the plugging place is greater than or equal to 50N/cm, and when the peel strength is 50N /cm～100N/cm, at least 80% of the surface is cohesive failure, when the peel strength is greater than 100N/cm, it can be interface failure, and the peeling primer should be completely attached to the surface of the pipe.

Preferably, in step E, according to the actual number of repaired ports and blocked ports, at least one port is randomly inspected for every 100 ports. If it is unqualified, the sampling test is doubled.

Preferably, when one of the following conditions is encountered in the fast blocking method for the reserved interface of the long-distance pipeline, the open-air blocking is not performed: rainy, snowy or sandy days; the wind force reaches level 5 or above; the relative humidity is greater than 85%; the environment The temperature is below 0°C.

The advantages of the invention are as follows: lightweight heating equipment is used during construction, which is easy to carry; heat shrinkable tape is a commonly used material for construction and is easy to obtain; construction speed is fast, and it only takes 15 minutes to block one pipe end, saving a lot of time; construction does not need to occupy Welders who are in short supply of long-distance pipelines can ensure the continuous development of welding work of the main pipeline; no need to do flaw detection after blocking, which saves the cost of flaw detection; it is convenient to remove the heat shrinkable tape; The joints are paired to improve the welding quality; the pipe ends are wrapped by heat shrinkable tape after plugging, which has good anti-corrosion effect and can be kept in a humid environment for a long time; compared with the traditional method of welding blind plates, the construction process is simple, safe and reliable.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the present invention. examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The present embodiment discloses a method for quickly plugging a reserved interface of a long-distance pipeline, comprising the following steps:

Step A, preprocessing the reserved interface, which specifically includes the following steps:

Step a1, use a portable liquefied gas tank gun to perform surface heat treatment on the reserved interface, so that the surface temperature of the reserved interface is preheated to at least 5°C above the dew point.

Step a2, after the heat treatment is completed, remove rust on the surface of the reserved interface; if manual rust removal is used, the rust removal grade reaches St3; if sandblasting is used, the rust removal grade reaches Sa21/2; keep the surface dry , No loose rust, no dirt.

Step a3, according to the product instructions, prepare the primer for anti-corrosion repair and evenly brush it to the reserved interface. The thickness of the primer is greater than or equal to 150um.

Step B, use a heat shrinkable tape with a width larger than the diameter of the pipe to lay flat at the reserved interface, wrap the heat shrinkable tape around the pipe end, and the lap length of the shrinkage tape and the outer wall of the pipe end is required to be greater than or equal to 100mm after shrinking; The sheet overlaps with the heat shrinkable tape along the pipe diameter direction, and the overlap length of the fixing sheet and the heat shrinkable tape is required to be greater than or equal to 80mm after shrinkage.

Step C, use the portable liquefied gas tank gun to evenly heat the reserved interface, move the portable liquefied gas tank gun slowly during heating, and do not heat any point of the heat shrinkable tape for a long time.

Step D, after heating, wait for the heat-shrinkable tape to naturally cool and shrink; during the shrinkage process of the heat-shrinkable tape, a finger pressure method is used to check the fluidity of the glue, and it is qualified if the finger indentation disappears automatically.

Step E: After the plugging is completed, the quality of the plugging is checked. According to the actual filling and the number of plugging, at least one port is sampled for every 100. If it is unqualified, the sampling test will be doubled. step:

In step e1, visually inspect the appearance of the reserved interface, and it is required that the plugging part is flat, without wrinkles, no bubbles, and no charring and carbonization, and there is an even overflow of adhesive around the heat shrinkable tape. The displacement is less than or equal to 5mm.

Step e2, use an electric spark leak detector to perform leak detection on the reserved interface, and the detection voltage is 15kV. If there is a leak, re-block and perform leak detection again until no leak is detected;

Step e3, use peel strength testing equipment to test the peel strength of the reserved interface, the temperature of the pipe body during the test is 15°C to 25°C, the qualified standard is that the peel strength at the plugging place is greater than or equal to 50N/cm, and when the peel strength is 50N /cm～100N/cm, at least 80% of the surface is cohesive failure, when the peel strength is greater than 100N/cm, it can be interface failure, and the peeling primer should be completely attached to the surface of the pipe.

The quick blocking method for the reserved interface of the long-distance pipeline does not perform open-air blocking when one of the following conditions is encountered: rainy, snowy or sandy days; wind force reaches level 5 or above; relative humidity is greater than 85%; ambient temperature is lower than 0°C.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (8)

1. A rapid plugging method for a reserved connector of a long-distance pipeline is characterized by comprising the following steps: the method comprises the following steps:

step A, preprocessing a reserved interface;

b, using a heat-shrinkable belt with the width larger than the diameter of the pipeline to spread at the reserved interface, and wrapping the pipe end with the heat-shrinkable belt; then the stator is lapped with the thermal contraction belt along the pipe diameter direction;

step C, uniformly heating the reserved interface by using heating equipment;

d, after heating is finished, waiting for the natural cooling shrinkage of the heat shrinkable tape, and finishing plugging;

and E, detecting the plugging quality after plugging is finished.

2. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: the step A specifically comprises the following steps:

step a1, performing surface heat treatment on a reserved interface by using a portable liquefied gas tank gun to ensure that the surface temperature of the reserved interface is preheated to be at least 5 ℃ above a dew point;

step a2, after the heat treatment is finished, derusting the surface of the reserved connector; if a manual rust removing mode is adopted, the rust removing grade reaches St3 grade; if a sand blasting rust removal mode is adopted, the rust removal grade reaches Sa2 ¹ / ₂ A stage;

step a3, blending the primer for the anticorrosion repaired mouth according to the product specification, and uniformly coating the primer to the reserved interface, wherein the coating thickness of the primer is more than or equal to 150um.

3. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: in the step B, the lapping length of the thermal contraction belt and the outer wall of the pipe end is required to be more than or equal to 100mm after contraction, and the lapping length of the fixing piece and the thermal contraction belt is required to be more than or equal to 80mm after contraction.

4. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: in the step C, the heating equipment adopts a portable liquefied gas tank gun.

5. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: and D, checking the fluidity of the glue by adopting a finger pressing method in the shrinkage process of the heat shrinkable tape, and automatically eliminating the finger indentation to obtain the qualified product.

6. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: the step E specifically comprises the following steps:

step e1, visually inspecting the appearance of the reserved interface;

e2, using an electric spark leak detector to perform leakage point detection on the reserved interface, wherein the detection voltage is 15kV, if the leakage point exists, plugging again and performing leakage point detection again until no leakage point is detected;

and e3, detecting the peel strength of the reserved interface by using peel strength detection equipment, wherein the temperature of the pipe body is 15-25 ℃ during detection, the qualified standard is that the peel strength of the plugging part is greater than or equal to 50N/cm, at least 80% of the surface is in cohesive failure when the peel strength is 50N/cm-100N/cm, the surface can be in interfacial failure when the peel strength is greater than 100N/cm, and the peel surface primer is required to be completely attached to the surface of the pipeline.

7. The method for rapidly plugging the reserved connector of the long-distance pipeline according to claim 1, wherein the method comprises the following steps: and E, performing at least one sampling inspection on every 100 ports according to the actual number of repaired ports and plugged ports, performing double sampling inspection if the repaired ports are not qualified, and performing complete repair if the repaired ports are not qualified.

8. The rapid plugging method for the reserved connector of the long-distance pipeline according to claim 1, characterized in that: when the rapid plugging method for the reserved interface of the long-distance pipeline meets one of the following conditions, open plugging is not performed: rainy, snowy or sandy days; wind power reaches more than 5 grades; relative humidity greater than 85%; the ambient temperature is below 0 ℃.