How to treat oil leakage from transformer weld on site?

Most of the seals of the transformer are in the upper part, and under normal circumstances, only a little oil is needed to repair the replacement seals on the spot. Draining oil to replace seals requires clean oil tanks, oil pumps, vacuum pumps, etc., which is very troublesome. The sealing surface should be cleaned, and no grease and debris are allowed to adhere to it, because these small defects often form a very fine oil seepage channel.

Before placing the seal, the insulating oil on the seal surface needs to be wiped clean.

There are two methods of on-site repair welding, one is oil drain repair welding, which requires sufficient downtime and clean special equipment, which is more troublesome. Therefore, another method is often used --- repair welding with oil for treatment. Gas welding is generally prohibited for oil repair welding, but in the case of electric welding, in order to prevent penetrating fire, the welding time should be controlled within 30 seconds each time, and the welding should be stopped for a few minutes to avoid burning and **.

When welding around the sealant gasket and rubber strip, the asbestos rope should be dipped in water and surrounded by the sealant gasket and rubber strip for cooling, and intermittent welding should be carried out to prevent the rubber pad from aging or burning, resulting in aggravated oil leakage on the sealing surface; For radiators, heat pipes and thin-walled containers, it is not recommended to weld and repair them on site due to safety factors.

1) The chemical bond connection force formed after the curing of the polymer composite material makes it form an excellent adhesion with the repaired metal parts, which meets the requirements of the equipment to withstand various composite forces in operation. The material has good chemical properties of various media and various oils and good anti-aging properties, which can provide a long-term protective layer for the parts. Compared with traditional welding or replacement parts, polymer composite materials have the characteristics of simple construction, low cost, high safety and good treatment effect.

2) Repair process.

a. Treat the bonded surface with mechanical methods such as grinding to expose the original color of the metal and roughen the bonded surface.

b. Clean the surface with absolute ethanol to make the surface clean and free of debris.

c. Mix 25551 polymer material evenly in proportion to make it quickly plug the leakage point.

d. Proportionally blend 2211F polymer composites evenly and cover 25551 and extend 1cm outward.

e. Wait for the material to solidify.

There are two ways to deal with it:

1.If the leakage point is not very large, you can wipe the transformer oil at the leakage point first. After that, use the two brothers to glue it well.

2.If the leakage point is on the transformer box, then you can use a Yang Chong at the leakage point first, flush the leakage point with Yang Chong, and then glue it with Brother Lianghao. Both methods are possible.

When dealing with it, it is necessary to ensure that the transformer on the site is in a state of power failure, and to hang up the primary and secondary grounding wires, so as to ensure personal safety.

For transformer oil leakage, it is recommended to try to use Soray SD2240 carbon nanomaterial technology to treat leakage without disassembly on site, and directly treat it from the leakage site.

There seems to be no good way for flange oil to seep, so you can only tighten the flange bolts to try. If the oil seal rubber is rotten, not only is the fastening bolt useless and even the oil leakage will be aggravated, and this situation must be replaced.

Two carbon nanopolymer materials, SD2240 and SD3010, were used together to repair the oil leakage problem of the joint surface of the transformer flange in the field.

1. Oil leakage at the weld.

Mainly due to poor welding quality, there are virtual welding, desoldering, pinholes, sand holes and other defects in the weld, the transformer is covered with flux and paint when it leaves the factory, and the hidden dangers will be exposed after operation, and the electromagnetic vibration will cause welding cracks, resulting in leakage. For those who have leakage, first find out the leakage point, and do not omit it. For the serious leakage parts, metal tools such as flat shovels or sharp punches can be used to rivet the leakage point, and the treatment surface will be cleaned after controlling the amount of leakage, and polymer composite materials can be used for curing, and the purpose of long-term leakage treatment can be achieved after curing.

2. Oil leakage from the seal.

The reason for poor sealing, usually the sealing of the box edge and the box cover is sealed with oil-resistant rubber rods or rubber pads, if the joint is not handled well, it will cause oil leakage failure, some are tied with plastic tape, and some directly press the two ends together, due to the rolling during installation, the interface can not be pressed, and it can not be sealed, and it is still leaking oil. Fushilan material can be used for bonding, so that the joint forms a whole, and the oil leakage phenomenon is greatly controlled; If the operation is convenient, the metal shell can also be bonded at the same time to achieve the purpose of leakage control.

3. Oil leakage at the flange connection.

The flange surface is uneven, the fastening bolt is loose, and the installation process is incorrect, so that the bolt is not fastened well, resulting in oil leakage. After the loose bolts are tightened first, the flanges are sealed, and the bolts that may leak are also treated to achieve complete treatment. The tightening of loose bolts must be carried out in strict accordance with the operation process.

4. Oil leakage from iron castings.

The main cause of oil leakage is sand holes and cracks in iron castings. For crack leakage, drilling crack stops is the best way to relieve stress and avoid elongation. According to the condition of the crack, the lead wire can be driven into the leakage point or riveted with a hand hammer.

The leak point is then cleaned with acetone and sealed with material. Cast sand holes can be sealed directly with the material.

5. Oil leakage from bolts or pipe threads.

When leaving the factory, the processing is rough, the sealing is poor, and the transformer will leak oil failure after a period of time of sealing. Polymer materials are used to seal the bolts to achieve the purpose of leakage control. Another method is to screw out the bolt (nut), apply the surface with Fushilan release agent, and then tighten it after applying the material on the surface, and then achieve the purpose of treatment after curing.

6. Oil leakage from radiator.

The heat pipe of the radiator is usually made of stamping after flattening the steel pipe with seams, and the oil leakage often occurs in the bent part and the welded part of the heat pipe, which is because when the heat pipe is stamped, the outer wall of the pipe is under tension, and its inner wall is under pressure, and there is residual stress. Close the upper and lower plate valves (butterfly valves) of the radiator to isolate the oil in the radiator from the oil in the box to reduce the pressure and leakage. After determining the leakage site, appropriate surface treatment is carried out, and then the sealing treatment is carried out with Fushi Blue material.

7. Leakage of oil from porcelain bottles and glass oil labels.

This is usually caused by improper installation or seal failure. Polymer composite materials can be well bonded to metal, ceramic, glass and other materials, so as to achieve the fundamental treatment of oil leakage.

Find out why and where.

Before dealing with oil seepage, it must be carefully analyzed to find out the cause of the leak and the exact leakage point. For the existing oil stains, first clean them with a small flat shovel and wire brush, then clean them with xylene, rinse them with clean water, and finally wipe them repeatedly with a clean cloth to find the exact location of the leakage point.

Handling scenarios. Transformer leakage can be roughly divided into sealing leakage and welding leakage. Dealing with seal leakage, mainly to improve the quality of sealing, such as casing, oil mark, radiator valve, large cover, on-load switch and other places containing seals, if the fastening screw is invalid, the sealing ring can be replaced or re-glued and sealed; To deal with welding leakage, repair welding can be adopted. Regardless of the type of oil that is being treated, it is forbidden to use the thick material method or the lashing method.

The pressure-bearing area of the sealing rubber of the seal should be adapted to the force of the screw, otherwise it is difficult to compress; When replacing the oil plug rubber sealing ring, the valves and channels at the inlet of the part should be closed, and the seal should be replaced under the condition that the negative pressure is maintained to a large amount of oil, and the seal should have good oil resistance and anti-aging performance, good elasticity and mechanical properties, and the sealing material should avoid using materials such as asbestos packing and cork mat as much as possible.

Parts with poor structure or unreasonable sealing methods, such as radiator and oil purifier connection flange strength is not enough, easy to deform when tightening bolts, so that the flange can not be tightly pressed gasket, should be modified or replaced. The crimping plane at the seal should be smooth and clean, and it is best to apply a layer of adhesive glue such as PVC, varnish, etc. when placing the rubber pad.

When a leak is found in the upper part of the welding transformer oil tank, only a small amount of oil needs to be discharged to weld it; When leakage is found in the lower part of the oil tank, due to the large waste of oil discharge in the core and limited by the on-site conditions, it can be welded with oil. Repair welding with oil should be carried out under the condition that the oil leakage is not significant, otherwise the vacuum should be welded after the vacuum discharge method caused by negative pressure, and the vacuum degree of negative pressure should not be too high, and the internal and external pressure should be equal to avoid inhaling molten iron.

Gas welding is generally forbidden to be used for oil repair welding; Welding selection of thinner electrodes, such as electrodes is appropriate; When repairing welding, the oil stains on the welding part should be cleaned, and it is best to rinse with alkaline water and then wipe dry; During the welding process, attention should be paid to prevent penetration and ignition, and the welding part must be below the oil level; Intermittent and rapid spot welding is used when welding, and the arc time should be controlled within 10s and 20s, and long-term continuous welding is absolutely not allowed.

When the pores with serious oil leakage can be plugged or riveted with iron wires before welding; Cooling and protection measures should be taken when welding near sealing rubber gaskets or other vulnerable parts.

The sand hole on the sand hole casting can be plugged by pressure with Diyou No. 1 plugging glue, and after the blockage, pay attention to reinforcement, and then use a hair dryer to blow and bake for 5min 15min until it is cured. When plugging the leak, the oil stains should be wiped clean first.

1. Observe first, whether it is oil leakage or oil seepage, the key to the difference is that whether the oil is dripping and only attached to the surface, oil seepage can be temporarily left untreated, continue to run, 2, handle work tickets, power outage applications, operation tickets and other management safety measures 3, technical safety measures, power outages, power inspection, and grounding.

4. Check the oil leakage part, if it is the shell oil leakage, it will be sent to the factory for repair, but most of the cases are oil leakage at the pillar porcelain bottle of the pile head, the usual treatment measure is to replace the aging rubber gasket, sometimes the oil leakage is at the gas relay, depending on the situation, or tighten the screw or replace the relay.

Just replace the gasket. If you are in Jinan, look for me. If it's too far. You can find your local power supply bureau.

There are several possible causes of transformer oil leakage.

1. Welding quality problems of the same material, such as oil tank and body, radiator and body, etc

2. There is trachoma in the steel plate of the box body, and oil seepage occurs.

3. The screws of the large cover and the main body are not tight or the tightness of the screws is uneven, and the sealing gasket is not properly placed or the gasket fails, resulting in oil leakage between the large cover and the main body.

4. The connection parts of a variety of materials are not real, resulting in oil leakage, such as the gas relay flange of the transformer, the transformer bushing, the transformer oil standard, etc.

5. The transformer porcelain bushing is deformed, the installation is not correct, the crack or the gasket has problems, resulting in the unreal oil seepage between the bushing and the body.

6. The transformer bushing is not matched with the conductive rod or the gasket is not tightly sealed, resulting in oil leakage at the conductive rod on the bushing.

7. The transformer oil drain valve is not closed tightly.

8. Oil seepage caused by other reasons, such as short circuit, overload, etc.

1.Poor product quality.

The transformers produced in the early days of China use ordinary plate butterfly valves, which may have rough connection surfaces and single-layer seals, which are particularly easy to cause oil leakage and other phenomena. They have now been phased out. In the manufacturing process of today's transformers, there are many welding joints in the fuel tank, and the welding process is difficult.

And there are many factors that affect the quality of welding. It is easy to cause porosity, false welding, desoldering and sand holes.

2.Improper transportation.

During each transportation process, the various parts of the transformer collide and cause damage. Violent transportation will cause some parts to deform, crack and even open and unweld some welding places.

3.Improper installation.

In the case of high quality products and meticulous transportation, if the installation is not done properly, the previous efforts are almost in vain. There are often workers who install violently, or lack of professional skills in installation, the flange connection will be uneven, resulting in uneven force on the gasket and unable to achieve the sealing effect; secondly, the bolts around the gasket are artificially stressed unevenly, and the results are the same as above; The third flange joint is deformed and misplaced, and the force at both ends of the gasket is different, resulting in insufficient compression. Finally, the installation of the gasket is that insufficient compression can easily lead to oil leakage, and excessive compression can easily lead to accelerated aging of the sealing ring.

4.Seal failure or crack weld.

As mentioned above, the transformer has many welding joints and long welds, so in the process of use, its seals will fail or its welding may crack, porosity and other problems.

5.Seals are aged and deformed.

Oil leaks from transformers often occur at the joints, and the majority of these leaks are due to seals. Whether the seal is susceptible to aging and deformation depends mainly on its oil resistance. If the oil resistance is good, the aging rate will be slower.

From the common sense of life, we can guide that rubber rings are easy to age when exposed to high temperatures and exposure to the sun. Therefore, the sealing ring deteriorates quickly at high temperatures, which can easily lead to deformation of the area, which may eventually lead to failure.

In view of the above causes of transformer oil leakage, please refer to the article "Transformer Oil Leakage Countermeasures" for corresponding measures.

As the most important and indispensable equipment in the power supply system, the normal operation of the transformer has an important impact on the power system, so the transformer tester can be used to test the performance of the transformer before the transformer is put into operation. Screen out inferior transformers, improve the defects of transformers, and ensure the safe operation of the power grid.