Corrosion repair method for tail pipe of high-voltage single-core cable terminal

Abstract

The invention relates to a corrosion repair method for a high-voltage single-core cable terminal tail pipe. The method comprises the following steps: preprocessing the terminal tail pipe; original sealing lead or epoxy mud at the tail pipe is removed; cutting off the original metal sheath of the corrosion damage section; cable insulation shielding surface treatment and protection; pretreating a new metal sheath in a corrosion damage section; lead sealing connection of a new metal sheath; and finally, performing outer surface treatment and protection to finish corrosion repair of the tail pipe of the high-voltage single-core cable terminal. According to the invention, the electrical performance and the mechanical performance of the lead sealing part of the tail pipe of the cable terminal can be quickly and well recovered, the normal operation of the cable is ensured, and the potential engineering application value is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of cable operation, maintenance and repair, and in particular to a method for repairing corrosion of a high-voltage single-core cable terminal tail tube. Background Art

[0002] With the development of the power industry and the advancement of technology, high-voltage cables, as an important part of power transmission, have received more and more attention for their performance and safety. In the terminal structure of high-voltage power cables, the terminal tail tube mainly plays the role of grounding, current flow and sealing. When the terminal is installed, it is connected and sealed with sealing lead or epoxy mud to protect the internal insulation of the cable terminal from being damaged, and at the same time play a certain sealing role. The tail tube is mostly made of aluminum or copper. As a barrier, the tail tube can effectively prevent external moisture and humidity from invading the terminal, thereby ensuring the dryness and safety of the cable insulation; when a short-circuit fault occurs in the cable, the tail tube bears the short-circuit current and constitutes a channel for the short-circuit current discharge. At the same time, it also serves as a ground potential reference for the insulation layer of the cable terminal, which helps to ensure that the cable system can operate stably under different working conditions.

[0003] When the terminal tail pipe is poorly connected or the seal is defective, long-term operation will cause the cable metal sheath at the tail pipe to corrode, break and crack, resulting in poor grounding, internal moisture and other problems, making the normal function of the lead sealing connection at the tail pipe ineffective. Long-term operation will cause local water ingress and corrosion, damage the cable body insulation and other problems, causing breakdown failures. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a method for repairing corrosion of a high-voltage single-core cable terminal tail tube, which can quickly and well restore the electrical and mechanical properties of the lead sealing part of the cable terminal tail tube, ensure the normal operation of the cable, and has potential engineering application value.

[0005] The present invention solves the technical problem by adopting the following technical solutions:

[0006] A method for repairing corrosion of a high-voltage single-core cable terminal tail tube comprises the following steps:

[0007] Step 1: Pretreatment of the terminal tail pipe;

[0008] Step 2: Remove the original lead seal or epoxy mud at the tail pipe;

[0009] Step 3: removing the original metal sheath from the corroded and damaged section;

[0010] Step 4: Surface treatment and protection of cable insulation shielding;

[0011] Step 5: Pretreatment of new metal sheath in the corroded and damaged section;

[0012] Step 6: New metal sheath seal lead connection;

[0013] Step 7: External surface treatment and protection.

[0014] Moreover, the specific implementation method of step 1 is: use an electrician's knife to remove the heat shrink tube and the wrapping tape at the tail of the terminal tail tube in sequence, and avoid damaging the remaining components and cables of the terminal during the removal process.

[0015] Moreover, the specific implementation method of step 2 is: use special tools to remove the epoxy mud or sealing lead at the tail of the terminal, then remove the copper braided belt, use special tools to straighten the tail pipe end, remove the bolts on the terminal tail pipe flange, temporarily withdraw the tail pipe and sealing ring to the position below the break of the cable outer sheath and fix it.

[0016] Moreover, the specific implementation method of step 3 is: remove the metal sheath that is severely corroded or damaged locally, peel off 40mm of the cable outer sheath from the cut point downward to expose the metal sheath, and remove the graphite layer within 40mm below the outer sheath break.

[0017] Moreover, the specific implementation method of step 4 is: half-overlapping the newly exposed cable insulation shield with a semi-conductive tape, a lead tape, a copper mesh tape, and a transparent PVC adhesive tape in sequence, requiring that one end overlaps the metal sheath by no less than 20 mm, and the other end overlaps the originally wrapped semi-conductive tape, lead tape, copper mesh tape, and transparent PVC adhesive tape by no less than 20 mm.

[0018] Moreover, the specific implementation method of step 5 is: measure the distance between the broken end of the metal sheath and the tail pipe, cut off two new metal sheaths of the same specifications, the length of the new metal sheath should be able to meet the overlap with the metal sheath and tail pipe on the cable by not less than 100mm; saw the newly prepared metal sheath in half, use a file to neaten the broken end of the new metal sheath, and cover it on the metal sheath of the cable; then use a wire brush to clean the lead sealing, welding marks and oxide layer on the surface of the terminal tail pipe and the cable metal sheath, and then use a sand belt to polish it, requiring it to expose the original color of the metal and the surface to be bright, and then clean it.

[0019] Moreover, the specific implementation method of step 6 is: clean the sealing silicone remaining on the tail pipe sealing groove and the surface of the sealing ring and the lower surface of the stress cone cover flange, ensure that there is no impurity on the surface, re-apply new sealing silicone in the tail pipe sealing groove, put the sealing ring into the sealing groove, assemble the tail pipe, and tighten the tail pipe fixing bolts symmetrically and evenly;

[0020] Insert the two half-arc liners into the tail pipe, then use special tools to bend the tail end of the tail pipe and overlap it with the new metal sheath, and then use aluminum welding rods to prime the lead sealing part of the metal sheath to improve the bonding degree between the lead sealing welding base material and the metal sheath;

[0021] Insert the lead welding rod into the two ports of the metal sheath and the broken end of the metal sheath, use a liquefied gas spray gun to heat the lead welding rod, use a special lead-lined cloth to fill the semi-molten solder into the overlapping joints at both ends of the metal sheath, and gradually expand the shape. The overlapping surfaces of the two sections of the metal sheath and the overlapping sections of the new metal sheath and the tail pipe should be completely covered by the lead seal.

[0022] Moreover, the specific implementation method of step 7 is: use copper braided tape to connect the end of the tail pipe to the surface of the cable metal sheath, which is required to be evenly distributed in a semicircle; then wrap the insulating tape and waterproof tape around the surface of the sealing lead and copper braided tape, requiring one end to cover the terminal tail pipe welding position and the other end to overlap the outer sheath of the cable; wrap the PVC adhesive tape around the waterproof tape, requiring it to completely cover the waterproof tape, and then wrap the armor tape around the PVC adhesive tape, and wrap the waterproof tape and PVC adhesive tape around the armor tape in turn.

[0023] The advantages and positive effects of the present invention are:

[0024] The present invention completes the corrosion repair of the high-voltage single-core cable terminal tail tube through pretreatment of the terminal tail tube; removal of the original lead sealing or epoxy mud at the tail tube; removal of the original metal sheath in the corroded and damaged section; surface treatment and protection of the cable insulation shield; pretreatment of the new metal sheath in the corroded and damaged section; lead sealing and connection of the new metal sheath; and final outer surface treatment and protection. The present invention can quickly and well restore the electrical and mechanical properties of the lead sealing of the cable terminal tail tube, ensure the normal operation of the cable, and has potential engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the present invention;

[0026] Figure 2 It is a schematic diagram of the tail pipe lead sealing repair structure of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings.

[0028] A method for repairing corrosion of a high-voltage single-core cable terminal tail tube, such as Figure 1 and Figure 2 As shown, the following steps are included:

[0029] A method for repairing corrosion of a high-voltage single-core cable terminal tail tube comprises the following steps:

[0030] Step 1: Pretreatment of the terminal tail pipe.

[0031] Use an electrician's knife to remove the heat shrink tube and wrapping tape at the end of the terminal tail tube in sequence, avoiding damage to other terminal components and cables during the removal process.

[0032] Step 2: Remove the original lead seal or epoxy mud from the tail pipe.

[0033] Use special tools to remove the epoxy mud / sealing lead at the tail of the terminal, then remove the copper braid, use special tools to straighten the end of the tail pipe, remove the bolts on the terminal tail pipe flange, temporarily withdraw the tail pipe and sealing ring to the position below the break of the cable outer sheath and fix it.

[0034] Step 3: Remove the original metal sheath from the corroded and damaged section.

[0035] Remove the metal sheath that is severely corroded or damaged locally, peel off the cable outer sheath 40mm downward from the cut-off point to expose the metal sheath, and remove the graphite layer within 40mm below the outer sheath break.

[0036] Step 4: Surface treatment and protection of cable insulation shielding.

[0037] Half-overlap semi-conductive tape, lead tape, copper mesh tape and transparent PVC adhesive tape in sequence on the newly exposed cable insulation shield. One end is required to overlap with the metal sheath by no less than 20mm, and the other end should overlap with the original semi-conductive tape, lead tape, copper mesh tape and transparent PVC adhesive tape by no less than 20mm.

[0038] Step 5: Pre-treat the new metal sheath in the corroded and damaged section.

[0039] Measure the distance between the broken end of the metal sheath and the tail tube, and cut two new metal sheaths of the same specifications. The length of the new metal sheath should be able to overlap the metal sheath and tail tube on the cable by no less than 100mm.

[0040] Saw the newly prepared metal sheath in half, use a file to neatly cut the new metal sheath, and cover it on the metal sheath of the cable. Then use a wire brush to clean the lead seal, welding marks and oxide layer on the tail of the terminal tail tube and the surface of the cable metal sheath, and then use an abrasive belt to polish it until the original color of the metal is exposed and the surface is bright, and then clean it.

[0041] Step 6: Seal the lead connection with the new metal sheath.

[0042] Clean the sealing silicone remaining on the tail pipe sealing groove, the surface of the sealing ring, and the lower surface of the stress cone cover flange. After ensuring that there is no impurity on the surface, re-apply new sealing silicone to the tail pipe sealing groove, put the sealing ring into the sealing groove, assemble the tail pipe, and tighten the tail pipe fixing bolts symmetrically and evenly.

[0043] Insert the two semi-arc liners into the tail pipe, then use special tools to bend the tail end of the tail pipe and overlap it with the new metal sheath, and then use aluminum welding rods to prime the lead sealing part of the metal sheath to improve the bonding degree between the lead sealing welding base material and the metal sheath.

[0044] Insert the lead welding rod into the two ports of the metal sheath and the broken end of the metal sheath, use a liquefied gas spray gun to heat the lead welding rod, use a special lead-lined cloth to fill the semi-molten solder into the overlapping joints at both ends of the metal sheath, and gradually expand the shape. The overlapping surfaces of the two sections of the metal sheath and the overlapping sections of the new metal sheath and the tail pipe should be completely covered by the lead seal.

[0045] Please note that reinstallation requires secondary lead sealing, which poses a risk of scalding the cable body and affecting the stable operation of the line. Pay attention to the risk of scalding the cable body when performing secondary lead sealing.

[0046] Step 7: External surface treatment and protection.

[0047] Use copper braided tape to connect the end of the tail tube to the surface of the cable metal sheath, which is required to be evenly distributed in a semicircle. Then wrap the insulation tape and waterproof tape on the surface of the lead seal and copper braided tape, with one end covering the terminal tail tube welding position and the other end overlapping the cable outer sheath.

[0048] Wrap the PVC adhesive tape around the waterproof tape, requiring it to completely cover the waterproof tape, and then wrap the armor tape around the PVC adhesive tape, and then wrap the waterproof tape and PVC adhesive tape around the armor tape.

[0049] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube, characterized in that: The following steps are involved: Step 1: Pretreatment of the terminal tail pipe; Step 2: Remove the original lead seal or epoxy mud at the tail pipe; Step 3: removing the original metal sheath from the corroded and damaged section; Step 4: Surface treatment and protection of cable insulation shielding; Step 5: Pretreatment of new metal sheath in the corroded and damaged section; Step 6: New metal sheath seal lead connection; Step 7: External surface treatment and protection.

2. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 1 is: use an electrician's knife to remove the heat shrink tube and the wrapping tape at the tail of the terminal tail tube in sequence, and avoid damaging the remaining components and cables of the terminal during the removal process.

3. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 2 is: use special tools to remove the epoxy mud or sealing lead at the tail of the terminal, then remove the copper braided belt, use special tools to straighten the tail pipe end, remove the bolts on the terminal tail pipe flange, temporarily withdraw the tail pipe and sealing ring to the position below the break of the cable outer sheath and fix it.

4. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 3 is: remove the metal sheath that is severely corroded or damaged locally, peel off 40 mm of the cable outer sheath from the cut-off point downward to expose the metal sheath, and remove the graphite layer within 40 mm below the outer sheath break.

5. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 4 is: half-overlapping the newly exposed cable insulation shield with a semi-conductive tape, a lead tape, a copper mesh tape, and a transparent PVC adhesive tape in sequence, requiring that one end overlaps the metal sheath by no less than 20 mm, and the other end overlaps the original semi-conductive tape, lead tape, copper mesh tape, and transparent PVC adhesive tape by no less than 20 mm.

6. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 5 is as follows: measure the distance between the broken end of the metal sheath and the tail pipe, cut off two new metal sheaths of the same specifications, the length of the new metal sheath should be able to meet the overlap with the metal sheath and tail pipe on the cable by not less than 100mm; saw the newly prepared metal sheath in half, use a file to neaten the broken end of the new metal sheath, and cover it on the metal sheath of the cable; then use a wire brush to clean the lead sealing, welding marks and oxide layer on the surface of the terminal tail pipe and the cable metal sheath, and then use an abrasive belt to polish it, requiring it to expose the original color of the metal and have a bright surface, and then clean it.

7. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 6 is: clean the sealing silicone remaining on the tail pipe sealing groove and the surface of the sealing ring and the lower surface of the stress cone cover flange, ensure that there is no impurities on the surface, re-apply new sealing silicone to the tail pipe sealing groove, put the sealing ring into the sealing groove, assemble the tail pipe, and tighten the tail pipe fixing bolts symmetrically and evenly; Insert the two half-arc liners into the tail pipe, then use special tools to bend the tail end of the tail pipe and overlap it with the new metal sheath, and then use aluminum welding rods to prime the lead sealing part of the metal sheath to improve the bonding degree between the lead sealing welding base material and the metal sheath; Insert the lead welding rod into the two ports of the metal sheath and the broken end of the metal sheath, use a liquefied gas spray gun to heat the lead welding rod, use a special lead-lined cloth to fill the semi-molten solder into the overlapping joints at both ends of the metal sheath, and gradually expand the shape. The overlapping surfaces of the two sections of the metal sheath and the overlapping sections of the new metal sheath and the tail pipe should be completely covered by the lead seal.

8. A method for repairing corrosion of a high-voltage single-core cable terminal tail tube according to claim 1, characterized in that: The specific implementation method of step 7 is: use copper braided tape to connect the end of the tail tube to the surface of the cable metal sheath, which is required to be evenly distributed in a semicircle; then wrap the insulating tape and waterproof tape on the surface of the sealing lead and copper braided tape, requiring one end to cover the terminal tail tube welding position and the other end to overlap the outer sheath of the cable; wrap the PVC adhesive tape outside the waterproof tape, requiring it to completely cover the waterproof tape, and then wrap the armor tape outside the PVC adhesive tape, and wrap the waterproof tape and PVC adhesive tape outside the armor tape in turn.

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