Various problems of transformer oil leakage

1. Treatment of oil leakage at welding points
Causes of the problem:
Mainly due to poor welding quality, false welding, desoldering, pinholes, sand holes and other defects in the welds. The transformer is covered with flux and paint when it leaves the factory, and the hidden dangers are exposed after operation. In addition, electromagnetic vibration will cause welding vibration and cracking, causing leakage.
Solutions:
For leakage, first find the leakage point and do not miss it. It is necessary to clean it continuously, find the source of the leakage along the oil trace, and use water-oil compatible supplements to seal the leakage point. After curing, the purpose of long-term leakage control can be achieved.

2. Oil leakage of cast iron parts
Causes of the problem:
The main reason for oil leakage is sand holes and cracks in cast iron parts.
Solutions:
①For crack leakage, drilling crack stop holes is a method to eliminate stress and avoid extension. When treating, according to the situation of the crack, lead wire can be driven into the leakage point or riveted with a hand hammer. Then clean the leak with acetone, and seal it with water-oil compatibility supplement and titanium steel glue.

3. Radiator oil leakage
Cause of the problem:
The heat pipe of the radiator is usually made by flattening the seamed steel pipe and then stamping it. Oil leakage often occurs in the bending and welding parts of the heat pipe. This is because when stamping the heat pipe, the outer wall of the pipe is under tension and the inner wall is under pressure, resulting in residual stress.

Technical solution to the problem:
After determining the leakage site, appropriate surface treatment is carried out. First, titanium steel glue is used for rapid sealing and sealing treatment. After curing, water-oil compatible repair agent is used for windowing No. 2·Transformer operation and maintenance

4. Oil leakage at the flange connection
Cause of the problem
The flange surface is uneven, the fastening bolts are loose, and the installation process is incorrect, which makes the bolts poorly tightened and the seals age and crack, causing oil leakage.
Technical solution to the problem
First tighten the loose bolts, use water-oil compatible repair agent to seal the bolts, and then treat the leaking flange surface to achieve the purpose of complete treatment. Tighten the loose bolts
Seal oil leakage

5. ColorCause of the problem
Poor sealing causes, usually the seal between the box edge and the box cover is sealed with oil-resistant rubber rods or rubber gaskets. If the joints are not handled well, it will cause oil leakage. Due to installation reasons, the interface cannot be pressed firmly and cannot play a sealing role, and it still leaks oil.
Technical solution to the problem: Use water-oil compatible repair agent for bonding to make the joint form 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, including the bolt part, to achieve the purpose of leakage control.

With the development of the power industry, how to improve the performance of power equipment and ensure the reliable operation of the power system is an urgent problem to be solved in power production. Therefore, whether the oil leakage problem of the transformer can be dealt with in a timely and thorough manner has gradually become an important technical indicator for measuring the development of the power industry. The phenomenon of oil leakage in oil-immersed power transformers is relatively common in the power system. If there is oil leakage in the transformer, it may affect the safe and stable operation of the transformer.

How to solve the problem of transformer oil leakage has been a major problem in the actual production of the power department for many years. Analysis of the causes of transformer oil leakage According to operating experience, transformer oil leakage generally occurs in the following 7 main parts: ① the connection surface of the main cover; ② radiator; ③ sampling valve: ④ casing: oil pipe flange surface: transformer base interface; ⑦ gas relay, etc. It can be found that most of the leakage points are flange joint surfaces, seals and valves. Unreasonable flange structure, poor quality of seal materials, poor processing technology, changes in external ambient temperature, pressure size, etc. can cause transformer leakage. These factors complement each other and have a common impact. When there is a problem in any of the links, it will cause a chain reaction and lead to oil leakage. The following specific analyses were conducted in practice:
First, the flange manufacturing process is unreasonable, and the leakage points at the oil drain plug of the transformer radiator interface account for more than half of the total leakage points. The reasons for the leakage are:

(1) There are rust, burrs, grooves and other phenomena on the contact surface;

(2) There are no sealing grooves and no limit pins;

 (3) There are paint and other dirt on the contact surface; when handling paint and debris, scars may be scratched on the sealing surface;

(4) The position and tightness of the sealing rubber ring are completely determined by experience. Too loose or too tight may cause leakage.
Second, the most commonly used sealing material is nitrile rubber. The sealing rings and gaskets made of it have poor oil resistance and age quickly. Especially at high temperatures, they are very easy to cause aging cracks and lose elasticity. In addition, during the installation process, the uneven finish of the sealing surface leads to increased compression and leakage.

With the development of the transformer industry, how to improve the performance of special transformer equipment and ensure the reliable operation of special transformers is an urgent problem to be solved in transformer production. Therefore, whether the oil leakage problem of special transformers can be dealt with in a timely and thorough manner has gradually become an important technical indicator for measuring the development of the transformer industry.